From fe6fb7135b7a0d74b179789838feae8bc1d3c71f Mon Sep 17 00:00:00 2001 From: Shay Banon Date: Wed, 10 Jul 2013 13:09:04 -0700 Subject: [PATCH] update to latest jsr166 --- src/main/java/jsr166e/CompletableFuture.java | 1598 +++- .../java/jsr166e/ConcurrentHashMapV8.java | 8325 ++++++++--------- src/main/java/jsr166e/CountedCompleter.java | 126 +- src/main/java/jsr166e/ForkJoinPool.java | 1424 ++- src/main/java/jsr166e/ForkJoinTask.java | 100 +- .../java/jsr166e/ForkJoinWorkerThread.java | 18 +- src/main/java/jsr166e/StampedLock.java | 137 +- src/main/java/jsr166e/extra/AtomicDouble.java | 11 +- .../java/jsr166e/extra/AtomicDoubleArray.java | 11 +- src/main/java/jsr166e/package-info.java | 9 - src/main/java/jsr166y/package-info.java | 2 +- 11 files changed, 5838 insertions(+), 5923 deletions(-) delete mode 100644 src/main/java/jsr166e/package-info.java diff --git a/src/main/java/jsr166e/CompletableFuture.java b/src/main/java/jsr166e/CompletableFuture.java index fbb3853e691..0d83582cc9e 100644 --- a/src/main/java/jsr166e/CompletableFuture.java +++ b/src/main/java/jsr166e/CompletableFuture.java @@ -5,11 +5,11 @@ */ package jsr166e; -import jsr166y.ThreadLocalRandom; - import java.util.concurrent.Future; +import java.util.concurrent.FutureTask; import java.util.concurrent.TimeUnit; import java.util.concurrent.Executor; +import java.util.concurrent.ThreadLocalRandom; import java.util.concurrent.ExecutionException; import java.util.concurrent.TimeoutException; import java.util.concurrent.CancellationException; @@ -19,52 +19,69 @@ import java.util.concurrent.locks.LockSupport; /** * A {@link Future} that may be explicitly completed (setting its * value and status), and may include dependent functions and actions - * that trigger upon its completion. Methods are available for adding - * those based on Functions, Blocks, and Runnables, depending on - * whether they require arguments and/or produce results, as well as - * those triggered after either or both the current and another - * CompletableFuture complete. Functions and actions supplied for - * dependent completions (mainly using methods with prefix {@code - * then}) may be performed by the thread that completes the current + * that trigger upon its completion. + * + *

When two or more threads attempt to + * {@link #complete complete}, + * {@link #completeExceptionally completeExceptionally}, or + * {@link #cancel cancel} + * a CompletableFuture, only one of them succeeds. + * + *

Methods are available for adding dependents based on + * user-provided Functions, Actions, or Runnables. The appropriate + * form to use depends on whether actions require arguments and/or + * produce results. Completion of a dependent action will trigger the + * completion of another CompletableFuture. Actions may also be + * triggered after either or both the current and another + * CompletableFuture complete. Multiple CompletableFutures may also + * be grouped as one using {@link #anyOf(CompletableFuture...)} and + * {@link #allOf(CompletableFuture...)}. + * + *

CompletableFutures themselves do not execute asynchronously. + * However, actions supplied for dependent completions of another + * CompletableFuture may do so, depending on whether they are provided + * via one of the async methods (that is, methods with names + * of the form xxxAsync). The async + * methods provide a way to commence asynchronous processing of an + * action using either a given {@link Executor} or by default the + * {@link ForkJoinPool#commonPool()}. To simplify monitoring, + * debugging, and tracking, all generated asynchronous tasks are + * instances of the marker interface {@link AsynchronousCompletionTask}. + * + *

Actions supplied for dependent completions of non-async + * methods may be performed by the thread that completes the current * CompletableFuture, or by any other caller of these methods. There * are no guarantees about the order of processing completions unless * constrained by these methods. * - *

When two or more threads attempt to {@link #complete} or {@link - * #completeExceptionally} a CompletableFuture, only one of them - * succeeds. + *

Since (unlike {@link FutureTask}) this class has no direct + * control over the computation that causes it to be completed, + * cancellation is treated as just another form of exceptional completion. + * Method {@link #cancel cancel} has the same effect as + * {@code completeExceptionally(new CancellationException())}. * - *

Upon exceptional completion, or when a completion entails - * computation of a function or action, and it terminates abruptly - * with an (unchecked) exception or error, then further completions - * act as {@code completeExceptionally} with a {@link - * CompletionException} holding that exception as its cause. If a - * CompletableFuture completes exceptionally, and is not followed by a - * {@link #exceptionally} or {@link #handle} completion, then all of - * its dependents (and their dependents) also complete exceptionally - * with CompletionExceptions holding the ultimate cause. In case of a - * CompletionException, methods {@link #get()} and {@link #get(long, - * TimeUnit)} throw an {@link ExecutionException} with the same cause - * as would be held in the corresponding CompletionException. However, - * in these cases, methods {@link #join()} and {@link #getNow} throw - * the CompletionException, which simplifies usage especially within - * other completion functions. + *

Upon exceptional completion (including cancellation), or when a + * completion entails an additional computation which terminates + * abruptly with an (unchecked) exception or error, then all of their + * dependent completions (and their dependents in turn) generally act + * as {@code completeExceptionally} with a {@link CompletionException} + * holding that exception as its cause. However, the {@link + * #exceptionally exceptionally} and {@link #handle handle} + * completions are able to handle exceptional completions of + * the CompletableFutures they depend on. * - *

CompletableFutures themselves do not execute asynchronously. - * However, the {@code async} methods provide commonly useful ways to - * commence asynchronous processing, using either a given {@link - * Executor} or by default the {@link ForkJoinPool#commonPool()}, of a - * function or action that will result in the completion of a new - * CompletableFuture. To simplify monitoring, debugging, and tracking, - * all generated asynchronous tasks are instances of the tagging - * interface {@link AsynchronousCompletionTask}. + *

In case of exceptional completion with a CompletionException, + * methods {@link #get()} and {@link #get(long, TimeUnit)} throw an + * {@link ExecutionException} with the same cause as held in the + * corresponding CompletionException. However, in these cases, + * methods {@link #join()} and {@link #getNow} throw the + * CompletionException, which simplifies usage. * - *

jsr166e note: During transition, this class - * uses nested functional interfaces with different names but the - * same forms as those expected for JDK8. + *

Arguments used to pass a completion result (that is, for parameters + * of type {@code T}) may be null, but passing a null value for any other + * parameter will result in a {@link NullPointerException} being thrown. * * @author Doug Lea - * @since 1.8 */ public class CompletableFuture implements Future { // jsr166e nested interfaces @@ -111,9 +128,10 @@ public class CompletableFuture implements Future { * extends AtomicInteger so callers can claim the action via * compareAndSet(0, 1). The Completion.run methods are all * written a boringly similar uniform way (that sometimes includes - * unnecessary-looking checks, kept to maintain uniformity). There - * are enough dimensions upon which they differ that factoring to - * use common code isn't worthwhile. + * unnecessary-looking checks, kept to maintain uniformity). + * There are enough dimensions upon which they differ that + * attempts to factor commonalities while maintaining efficiency + * require more lines of code than they would save. * * 4. The exported then/and/or methods do support a bit of * factoring (see doThenApply etc). They must cope with the @@ -170,7 +188,7 @@ public class CompletableFuture implements Future { * CompletionException unless it is one already. Otherwise uses * the given result, boxed as NIL if null. */ - final void internalComplete(Object v, Throwable ex) { + final void internalComplete(T v, Throwable ex) { if (result == null) UNSAFE.compareAndSwapObject (this, RESULT, null, @@ -190,11 +208,14 @@ public class CompletableFuture implements Future { /* ------------- waiting for completions -------------- */ + /** Number of processors, for spin control */ + static final int NCPU = Runtime.getRuntime().availableProcessors(); + /** * Heuristic spin value for waitingGet() before blocking on * multiprocessors */ - static final int WAITING_GET_SPINS = 256; + static final int SPINS = (NCPU > 1) ? 1 << 8 : 0; /** * Linked nodes to record waiting threads in a Treiber stack. See @@ -249,7 +270,7 @@ public class CompletableFuture implements Future { private Object waitingGet(boolean interruptible) { WaitNode q = null; boolean queued = false; - int h = 0, spins = 0; + int spins = SPINS; for (Object r;;) { if ((r = result) != null) { if (q != null) { // suppress unpark @@ -265,15 +286,9 @@ public class CompletableFuture implements Future { postComplete(); // help release others return r; } - else if (h == 0) { - h = ThreadLocalRandom.current().nextInt(); - if (Runtime.getRuntime().availableProcessors() > 1) - spins = WAITING_GET_SPINS; - } else if (spins > 0) { - h ^= h << 1; // xorshift - h ^= h >>> 3; - if ((h ^= h << 10) >= 0) + int rnd = ThreadLocalRandom.current().nextInt(); + if (rnd >= 0) --spins; } else if (q == null) @@ -381,9 +396,11 @@ public class CompletableFuture implements Future { /* ------------- Async tasks -------------- */ /** - * A tagging interface identifying asynchronous tasks produced by + * A marker interface identifying asynchronous tasks produced by * {@code async} methods. This may be useful for monitoring, * debugging, and tracking asynchronous activities. + * + * @since 1.8 */ public static interface AsynchronousCompletionTask { } @@ -442,11 +459,11 @@ public class CompletableFuture implements Future { } static final class AsyncApply extends Async { - final Fun fn; final T arg; + final Fun fn; final CompletableFuture dst; AsyncApply(T arg, Fun fn, - CompletableFuture dst) { + CompletableFuture dst) { this.arg = arg; this.fn = fn; this.dst = dst; } public final boolean exec() { @@ -466,14 +483,14 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class AsyncBiApply extends Async { - final BiFun fn; + static final class AsyncCombine extends Async { final T arg1; final U arg2; + final BiFun fn; final CompletableFuture dst; - AsyncBiApply(T arg1, U arg2, - BiFun fn, - CompletableFuture dst) { + AsyncCombine(T arg1, U arg2, + BiFun fn, + CompletableFuture dst) { this.arg1 = arg1; this.arg2 = arg2; this.fn = fn; this.dst = dst; } public final boolean exec() { @@ -494,11 +511,11 @@ public class CompletableFuture implements Future { } static final class AsyncAccept extends Async { - final Action fn; final T arg; + final Action fn; final CompletableFuture dst; AsyncAccept(T arg, Action fn, - CompletableFuture dst) { + CompletableFuture dst) { this.arg = arg; this.fn = fn; this.dst = dst; } public final boolean exec() { @@ -517,14 +534,14 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class AsyncBiAccept extends Async { - final BiAction fn; + static final class AsyncAcceptBoth extends Async { final T arg1; final U arg2; + final BiAction fn; final CompletableFuture dst; - AsyncBiAccept(T arg1, U arg2, - BiAction fn, - CompletableFuture dst) { + AsyncAcceptBoth(T arg1, U arg2, + BiAction fn, + CompletableFuture dst) { this.arg1 = arg1; this.arg2 = arg2; this.fn = fn; this.dst = dst; } public final boolean exec() { @@ -543,6 +560,47 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } + static final class AsyncCompose extends Async { + final T arg; + final Fun> fn; + final CompletableFuture dst; + AsyncCompose(T arg, + Fun> fn, + CompletableFuture dst) { + this.arg = arg; this.fn = fn; this.dst = dst; + } + public final boolean exec() { + CompletableFuture d, fr; U u; Throwable ex; + if ((d = this.dst) != null && d.result == null) { + try { + fr = fn.apply(arg); + ex = (fr == null) ? new NullPointerException() : null; + } catch (Throwable rex) { + ex = rex; + fr = null; + } + if (ex != null) + u = null; + else { + Object r = fr.result; + if (r == null) + r = fr.waitingGet(false); + if (r instanceof AltResult) { + ex = ((AltResult)r).ex; + u = null; + } + else { + @SuppressWarnings("unchecked") U ur = (U) r; + u = ur; + } + } + d.internalComplete(u, ex); + } + return true; + } + private static final long serialVersionUID = 5232453952276885070L; + } + /* ------------- Completions -------------- */ /** @@ -561,14 +619,15 @@ public class CompletableFuture implements Future { abstract static class Completion extends AtomicInteger implements Runnable { } - static final class ApplyCompletion extends Completion { + static final class ThenApply extends Completion { final CompletableFuture src; final Fun fn; final CompletableFuture dst; final Executor executor; - ApplyCompletion(CompletableFuture src, - Fun fn, - CompletableFuture dst, Executor executor) { + ThenApply(CompletableFuture src, + Fun fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.fn = fn; this.dst = dst; this.executor = executor; } @@ -610,14 +669,15 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class AcceptCompletion extends Completion { + static final class ThenAccept extends Completion { final CompletableFuture src; final Action fn; final CompletableFuture dst; final Executor executor; - AcceptCompletion(CompletableFuture src, - Action fn, - CompletableFuture dst, Executor executor) { + ThenAccept(CompletableFuture src, + Action fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.fn = fn; this.dst = dst; this.executor = executor; } @@ -658,20 +718,20 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class RunCompletion extends Completion { - final CompletableFuture src; + static final class ThenRun extends Completion { + final CompletableFuture src; final Runnable fn; final CompletableFuture dst; final Executor executor; - RunCompletion(CompletableFuture src, - Runnable fn, - CompletableFuture dst, - Executor executor) { + ThenRun(CompletableFuture src, + Runnable fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.fn = fn; this.dst = dst; this.executor = executor; } public final void run() { - final CompletableFuture a; + final CompletableFuture a; final Runnable fn; final CompletableFuture dst; Object r; Throwable ex; @@ -702,16 +762,17 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class BiApplyCompletion extends Completion { + static final class ThenCombine extends Completion { final CompletableFuture src; final CompletableFuture snd; final BiFun fn; final CompletableFuture dst; final Executor executor; - BiApplyCompletion(CompletableFuture src, - CompletableFuture snd, - BiFun fn, - CompletableFuture dst, Executor executor) { + ThenCombine(CompletableFuture src, + CompletableFuture snd, + BiFun fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.snd = snd; this.fn = fn; this.dst = dst; this.executor = executor; @@ -753,7 +814,7 @@ public class CompletableFuture implements Future { if (ex == null) { try { if (e != null) - e.execute(new AsyncBiApply(t, u, fn, dst)); + e.execute(new AsyncCombine(t, u, fn, dst)); else v = fn.apply(t, u); } catch (Throwable rex) { @@ -767,16 +828,17 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class BiAcceptCompletion extends Completion { + static final class ThenAcceptBoth extends Completion { final CompletableFuture src; final CompletableFuture snd; final BiAction fn; final CompletableFuture dst; final Executor executor; - BiAcceptCompletion(CompletableFuture src, - CompletableFuture snd, - BiAction fn, - CompletableFuture dst, Executor executor) { + ThenAcceptBoth(CompletableFuture src, + CompletableFuture snd, + BiAction fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.snd = snd; this.fn = fn; this.dst = dst; this.executor = executor; @@ -817,7 +879,7 @@ public class CompletableFuture implements Future { if (ex == null) { try { if (e != null) - e.execute(new AsyncBiAccept(t, u, fn, dst)); + e.execute(new AsyncAcceptBoth(t, u, fn, dst)); else fn.accept(t, u); } catch (Throwable rex) { @@ -831,22 +893,23 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class BiRunCompletion extends Completion { - final CompletableFuture src; + static final class RunAfterBoth extends Completion { + final CompletableFuture src; final CompletableFuture snd; final Runnable fn; final CompletableFuture dst; final Executor executor; - BiRunCompletion(CompletableFuture src, - CompletableFuture snd, - Runnable fn, - CompletableFuture dst, Executor executor) { + RunAfterBoth(CompletableFuture src, + CompletableFuture snd, + Runnable fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.snd = snd; this.fn = fn; this.dst = dst; this.executor = executor; } public final void run() { - final CompletableFuture a; + final CompletableFuture a; final CompletableFuture b; final Runnable fn; final CompletableFuture dst; @@ -882,16 +945,49 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class OrApplyCompletion extends Completion { + static final class AndCompletion extends Completion { + final CompletableFuture src; + final CompletableFuture snd; + final CompletableFuture dst; + AndCompletion(CompletableFuture src, + CompletableFuture snd, + CompletableFuture dst) { + this.src = src; this.snd = snd; this.dst = dst; + } + public final void run() { + final CompletableFuture a; + final CompletableFuture b; + final CompletableFuture dst; + Object r, s; Throwable ex; + if ((dst = this.dst) != null && + (a = this.src) != null && + (r = a.result) != null && + (b = this.snd) != null && + (s = b.result) != null && + compareAndSet(0, 1)) { + if (r instanceof AltResult) + ex = ((AltResult)r).ex; + else + ex = null; + if (ex == null && (s instanceof AltResult)) + ex = ((AltResult)s).ex; + dst.internalComplete(null, ex); + } + } + private static final long serialVersionUID = 5232453952276885070L; + } + + static final class ApplyToEither extends Completion { final CompletableFuture src; final CompletableFuture snd; final Fun fn; final CompletableFuture dst; final Executor executor; - OrApplyCompletion(CompletableFuture src, - CompletableFuture snd, - Fun fn, - CompletableFuture dst, Executor executor) { + ApplyToEither(CompletableFuture src, + CompletableFuture snd, + Fun fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.snd = snd; this.fn = fn; this.dst = dst; this.executor = executor; @@ -935,16 +1031,17 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class OrAcceptCompletion extends Completion { + static final class AcceptEither extends Completion { final CompletableFuture src; final CompletableFuture snd; final Action fn; final CompletableFuture dst; final Executor executor; - OrAcceptCompletion(CompletableFuture src, - CompletableFuture snd, - Action fn, - CompletableFuture dst, Executor executor) { + AcceptEither(CompletableFuture src, + CompletableFuture snd, + Action fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.snd = snd; this.fn = fn; this.dst = dst; this.executor = executor; @@ -987,22 +1084,23 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class OrRunCompletion extends Completion { - final CompletableFuture src; + static final class RunAfterEither extends Completion { + final CompletableFuture src; final CompletableFuture snd; final Runnable fn; final CompletableFuture dst; final Executor executor; - OrRunCompletion(CompletableFuture src, - CompletableFuture snd, - Runnable fn, - CompletableFuture dst, Executor executor) { + RunAfterEither(CompletableFuture src, + CompletableFuture snd, + Runnable fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.snd = snd; this.fn = fn; this.dst = dst; this.executor = executor; } public final void run() { - final CompletableFuture a; + final CompletableFuture a; final CompletableFuture b; final Runnable fn; final CompletableFuture dst; @@ -1034,6 +1132,38 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } + static final class OrCompletion extends Completion { + final CompletableFuture src; + final CompletableFuture snd; + final CompletableFuture dst; + OrCompletion(CompletableFuture src, + CompletableFuture snd, + CompletableFuture dst) { + this.src = src; this.snd = snd; this.dst = dst; + } + public final void run() { + final CompletableFuture a; + final CompletableFuture b; + final CompletableFuture dst; + Object r, t; Throwable ex; + if ((dst = this.dst) != null && + (((a = this.src) != null && (r = a.result) != null) || + ((b = this.snd) != null && (r = b.result) != null)) && + compareAndSet(0, 1)) { + if (r instanceof AltResult) { + ex = ((AltResult)r).ex; + t = null; + } + else { + ex = null; + t = r; + } + dst.internalComplete(t, ex); + } + } + private static final long serialVersionUID = 5232453952276885070L; + } + static final class ExceptionCompletion extends Completion { final CompletableFuture src; final Fun fn; @@ -1054,7 +1184,7 @@ public class CompletableFuture implements Future { (r = a.result) != null && compareAndSet(0, 1)) { if ((r instanceof AltResult) && - (ex = ((AltResult)r).ex) != null) { + (ex = ((AltResult)r).ex) != null) { try { t = fn.apply(ex); } catch (Throwable rex) { @@ -1072,16 +1202,16 @@ public class CompletableFuture implements Future { } static final class ThenCopy extends Completion { - final CompletableFuture src; + final CompletableFuture src; final CompletableFuture dst; - ThenCopy(CompletableFuture src, + ThenCopy(CompletableFuture src, CompletableFuture dst) { this.src = src; this.dst = dst; } public final void run() { - final CompletableFuture a; + final CompletableFuture a; final CompletableFuture dst; - Object r; Object t; Throwable ex; + Object r; T t; Throwable ex; if ((dst = this.dst) != null && (a = this.src) != null && (r = a.result) != null && @@ -1092,7 +1222,8 @@ public class CompletableFuture implements Future { } else { ex = null; - t = r; + @SuppressWarnings("unchecked") T tr = (T) r; + t = tr; } dst.internalComplete(t, ex); } @@ -1100,13 +1231,39 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } + // version of ThenCopy for CompletableFuture dst + static final class ThenPropagate extends Completion { + final CompletableFuture src; + final CompletableFuture dst; + ThenPropagate(CompletableFuture src, + CompletableFuture dst) { + this.src = src; this.dst = dst; + } + public final void run() { + final CompletableFuture a; + final CompletableFuture dst; + Object r; Throwable ex; + if ((dst = this.dst) != null && + (a = this.src) != null && + (r = a.result) != null && + compareAndSet(0, 1)) { + if (r instanceof AltResult) + ex = ((AltResult)r).ex; + else + ex = null; + dst.internalComplete(null, ex); + } + } + private static final long serialVersionUID = 5232453952276885070L; + } + static final class HandleCompletion extends Completion { final CompletableFuture src; final BiFun fn; final CompletableFuture dst; HandleCompletion(CompletableFuture src, BiFun fn, - final CompletableFuture dst) { + CompletableFuture dst) { this.src = src; this.fn = fn; this.dst = dst; } public final void run() { @@ -1140,20 +1297,23 @@ public class CompletableFuture implements Future { private static final long serialVersionUID = 5232453952276885070L; } - static final class ComposeCompletion extends Completion { + static final class ThenCompose extends Completion { final CompletableFuture src; final Fun> fn; final CompletableFuture dst; - ComposeCompletion(CompletableFuture src, - Fun> fn, - final CompletableFuture dst) { + final Executor executor; + ThenCompose(CompletableFuture src, + Fun> fn, + CompletableFuture dst, + Executor executor) { this.src = src; this.fn = fn; this.dst = dst; + this.executor = executor; } public final void run() { final CompletableFuture a; final Fun> fn; final CompletableFuture dst; - Object r; T t; Throwable ex; + Object r; T t; Throwable ex; Executor e; if ((dst = this.dst) != null && (fn = this.fn) != null && (a = this.src) != null && @@ -1172,17 +1332,18 @@ public class CompletableFuture implements Future { U u = null; boolean complete = false; if (ex == null) { - try { - c = fn.apply(t); - } catch (Throwable rex) { - ex = rex; + if ((e = executor) != null) + e.execute(new AsyncCompose(t, fn, dst)); + else { + try { + if ((c = fn.apply(t)) == null) + ex = new NullPointerException(); + } catch (Throwable rex) { + ex = rex; + } } } - if (ex != null || c == null) { - if (ex == null) - ex = new NullPointerException(); - } - else { + if (c != null) { ThenCopy d = null; Object s; if ((s = c.result) == null) { @@ -1224,13 +1385,13 @@ public class CompletableFuture implements Future { } /** - * Asynchronously executes in the {@link - * ForkJoinPool#commonPool()}, a task that completes the returned - * CompletableFuture with the result of the given Supplier. + * Returns a new CompletableFuture that is asynchronously completed + * by a task running in the {@link ForkJoinPool#commonPool()} with + * the value obtained by calling the given Generator. * * @param supplier a function returning the value to be used * to complete the returned CompletableFuture - * @return the CompletableFuture + * @return the new CompletableFuture */ public static CompletableFuture supplyAsync(Generator supplier) { if (supplier == null) throw new NullPointerException(); @@ -1241,14 +1402,14 @@ public class CompletableFuture implements Future { } /** - * Asynchronously executes using the given executor, a task that - * completes the returned CompletableFuture with the result of the - * given Supplier. + * Returns a new CompletableFuture that is asynchronously completed + * by a task running in the given executor with the value obtained + * by calling the given Generator. * * @param supplier a function returning the value to be used * to complete the returned CompletableFuture * @param executor the executor to use for asynchronous execution - * @return the CompletableFuture + * @return the new CompletableFuture */ public static CompletableFuture supplyAsync(Generator supplier, Executor executor) { @@ -1260,13 +1421,13 @@ public class CompletableFuture implements Future { } /** - * Asynchronously executes in the {@link - * ForkJoinPool#commonPool()} a task that runs the given action, - * and then completes the returned CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * by a task running in the {@link ForkJoinPool#commonPool()} after + * it runs the given action. * * @param runnable the action to run before completing the * returned CompletableFuture - * @return the CompletableFuture + * @return the new CompletableFuture */ public static CompletableFuture runAsync(Runnable runnable) { if (runnable == null) throw new NullPointerException(); @@ -1277,14 +1438,14 @@ public class CompletableFuture implements Future { } /** - * Asynchronously executes using the given executor, a task that - * runs the given action, and then completes the returned - * CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * by a task running in the given executor after it runs the given + * action. * * @param runnable the action to run before completing the * returned CompletableFuture * @param executor the executor to use for asynchronous execution - * @return the CompletableFuture + * @return the new CompletableFuture */ public static CompletableFuture runAsync(Runnable runnable, Executor executor) { @@ -1295,6 +1456,19 @@ public class CompletableFuture implements Future { return f; } + /** + * Returns a new CompletableFuture that is already completed with + * the given value. + * + * @param value the value + * @return the completed CompletableFuture + */ + public static CompletableFuture completedFuture(U value) { + CompletableFuture f = new CompletableFuture(); + f.result = (value == null) ? NIL : value; + return f; + } + /** * Returns {@code true} if completed in any fashion: normally, * exceptionally, or via cancellation. @@ -1306,13 +1480,12 @@ public class CompletableFuture implements Future { } /** - * Waits if necessary for the computation to complete, and then - * retrieves its result. + * Waits if necessary for this future to complete, and then + * returns its result. * - * @return the computed result - * @throws CancellationException if the computation was cancelled - * @throws ExecutionException if the computation threw an - * exception + * @return the result value + * @throws CancellationException if this future was cancelled + * @throws ExecutionException if this future completed exceptionally * @throws InterruptedException if the current thread was interrupted * while waiting */ @@ -1335,15 +1508,14 @@ public class CompletableFuture implements Future { } /** - * Waits if necessary for at most the given time for completion, - * and then retrieves its result, if available. + * Waits if necessary for at most the given time for this future + * to complete, and then returns its result, if available. * * @param timeout the maximum time to wait * @param unit the time unit of the timeout argument - * @return the computed result - * @throws CancellationException if the computation was cancelled - * @throws ExecutionException if the computation threw an - * exception + * @return the result value + * @throws CancellationException if this future was cancelled + * @throws ExecutionException if this future completed exceptionally * @throws InterruptedException if the current thread was interrupted * while waiting * @throws TimeoutException if the wait timed out @@ -1381,8 +1553,8 @@ public class CompletableFuture implements Future { * * @return the result value * @throws CancellationException if the computation was cancelled - * @throws CompletionException if a completion computation threw - * an exception + * @throws CompletionException if this future completed + * exceptionally or a completion computation threw an exception */ public T join() { Object r; Throwable ex; @@ -1408,8 +1580,8 @@ public class CompletableFuture implements Future { * @param valueIfAbsent the value to return if not completed * @return the result value, if completed, else the given valueIfAbsent * @throws CancellationException if the computation was cancelled - * @throws CompletionException if a completion computation threw - * an exception + * @throws CompletionException if this future completed + * exceptionally or a completion computation threw an exception */ public T getNow(T valueIfAbsent) { Object r; Throwable ex; @@ -1461,12 +1633,14 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed with - * the result of the given function of this CompletableFuture. - * If this CompletableFuture completes exceptionally, - * then the returned CompletableFuture also does so, - * with a CompletionException holding this exception as - * its cause. + * Returns a new CompletableFuture that is completed + * when this CompletableFuture completes, with the result of the + * given function of this CompletableFuture's result. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied function throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param fn the function to use to compute the value of * the returned CompletableFuture @@ -1477,49 +1651,58 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the {@link ForkJoinPool#commonPool()} with the - * result of the given function of this CompletableFuture. If - * this CompletableFuture completes exceptionally, then the - * returned CompletableFuture also does so, with a - * CompletionException holding this exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when this CompletableFuture completes, with the result of the + * given function of this CompletableFuture's result from a + * task running in the {@link ForkJoinPool#commonPool()}. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied function throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param fn the function to use to compute the value of * the returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture thenApplyAsync(Fun fn) { + public CompletableFuture thenApplyAsync + (Fun fn) { return doThenApply(fn, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the given executor with the result of the given - * function of this CompletableFuture. If this CompletableFuture - * completes exceptionally, then the returned CompletableFuture - * also does so, with a CompletionException holding this exception as - * its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when this CompletableFuture completes, with the result of the + * given function of this CompletableFuture's result from a + * task running in the given executor. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied function throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param fn the function to use to compute the value of * the returned CompletableFuture * @param executor the executor to use for asynchronous execution * @return the new CompletableFuture */ - public CompletableFuture thenApplyAsync(Fun fn, - Executor executor) { + public CompletableFuture thenApplyAsync + (Fun fn, + Executor executor) { if (executor == null) throw new NullPointerException(); return doThenApply(fn, executor); } - private CompletableFuture doThenApply(Fun fn, - Executor e) { + private CompletableFuture doThenApply + (Fun fn, + Executor e) { if (fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - ApplyCompletion d = null; + ThenApply d = null; Object r; if ((r = result) == null) { CompletionNode p = new CompletionNode - (d = new ApplyCompletion(this, fn, dst, e)); + (d = new ThenApply(this, fn, dst, e)); while ((r = result) == null) { if (UNSAFE.compareAndSwapObject (this, COMPLETIONS, p.next = completions, p)) @@ -1556,12 +1739,14 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed after - * performing the given action with this CompletableFuture's - * result when it completes. If this CompletableFuture - * completes exceptionally, then the returned CompletableFuture - * also does so, with a CompletionException holding this exception as - * its cause. + * Returns a new CompletableFuture that is completed + * when this CompletableFuture completes, after performing the given + * action with this CompletableFuture's result. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied action throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param block the action to perform before completing the * returned CompletableFuture @@ -1572,12 +1757,15 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the {@link ForkJoinPool#commonPool()} with this - * CompletableFuture's result when it completes. If this - * CompletableFuture completes exceptionally, then the returned - * CompletableFuture also does so, with a CompletionException holding - * this exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when this CompletableFuture completes, after performing the given + * action with this CompletableFuture's result from a task running + * in the {@link ForkJoinPool#commonPool()}. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied action throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param block the action to perform before completing the * returned CompletableFuture @@ -1588,12 +1776,15 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the given executor with this - * CompletableFuture's result when it completes. If this - * CompletableFuture completes exceptionally, then the returned - * CompletableFuture also does so, with a CompletionException holding - * this exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when this CompletableFuture completes, after performing the given + * action with this CompletableFuture's result from a task running + * in the given executor. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied action throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param block the action to perform before completing the * returned CompletableFuture @@ -1610,11 +1801,11 @@ public class CompletableFuture implements Future { Executor e) { if (fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - AcceptCompletion d = null; + ThenAccept d = null; Object r; if ((r = result) == null) { CompletionNode p = new CompletionNode - (d = new AcceptCompletion(this, fn, dst, e)); + (d = new ThenAccept(this, fn, dst, e)); while ((r = result) == null) { if (UNSAFE.compareAndSwapObject (this, COMPLETIONS, p.next = completions, p)) @@ -1650,11 +1841,14 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed after - * performing the given action when this CompletableFuture - * completes. If this CompletableFuture completes exceptionally, - * then the returned CompletableFuture also does so, with a - * CompletionException holding this exception as its cause. + * Returns a new CompletableFuture that is completed + * when this CompletableFuture completes, after performing the given + * action. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied action throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param action the action to perform before completing the * returned CompletableFuture @@ -1665,12 +1859,14 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the {@link ForkJoinPool#commonPool()} after - * performing the given action when this CompletableFuture - * completes. If this CompletableFuture completes exceptionally, - * then the returned CompletableFuture also does so, with a - * CompletionException holding this exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when this CompletableFuture completes, after performing the given + * action from a task running in the {@link ForkJoinPool#commonPool()}. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied action throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param action the action to perform before completing the * returned CompletableFuture @@ -1681,12 +1877,14 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the given executor after performing the given - * action when this CompletableFuture completes. If this - * CompletableFuture completes exceptionally, then the returned - * CompletableFuture also does so, with a CompletionException holding - * this exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when this CompletableFuture completes, after performing the given + * action from a task running in the given executor. + * + *

If this CompletableFuture completes exceptionally, or the + * supplied action throws an exception, then the returned + * CompletableFuture completes exceptionally with a + * CompletionException holding the exception as its cause. * * @param action the action to perform before completing the * returned CompletableFuture @@ -1703,11 +1901,11 @@ public class CompletableFuture implements Future { Executor e) { if (action == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - RunCompletion d = null; + ThenRun d = null; Object r; if ((r = result) == null) { CompletionNode p = new CompletionNode - (d = new RunCompletion(this, action, dst, e)); + (d = new ThenRun(this, action, dst, e)); while ((r = result) == null) { if (UNSAFE.compareAndSwapObject (this, COMPLETIONS, p.next = completions, p)) @@ -1738,50 +1936,60 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed with - * the result of the given function of this and the other given - * CompletableFuture's results when both complete. If this or - * the other CompletableFuture complete exceptionally, then the - * returned CompletableFuture also does so, with a - * CompletionException holding the exception as its cause. + * Returns a new CompletableFuture that is completed + * when both this and the other given CompletableFuture complete, + * with the result of the given function of the results of the two + * CompletableFutures. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied function throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param fn the function to use to compute the value of * the returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture thenCombine(CompletableFuture other, - BiFun fn) { - return doThenBiApply(other, fn, null); + public CompletableFuture thenCombine + (CompletableFuture other, + BiFun fn) { + return doThenCombine(other, fn, null); } /** - * Creates and returns a CompletableFuture that is asynchronously - * completed using the {@link ForkJoinPool#commonPool()} with - * the result of the given function of this and the other given - * CompletableFuture's results when both complete. If this or - * the other CompletableFuture complete exceptionally, then the - * returned CompletableFuture also does so, with a - * CompletionException holding the exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when both this and the other given CompletableFuture complete, + * with the result of the given function of the results of the two + * CompletableFutures from a task running in the + * {@link ForkJoinPool#commonPool()}. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied function throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param fn the function to use to compute the value of * the returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture thenCombineAsync(CompletableFuture other, - BiFun fn) { - return doThenBiApply(other, fn, ForkJoinPool.commonPool()); + public CompletableFuture thenCombineAsync + (CompletableFuture other, + BiFun fn) { + return doThenCombine(other, fn, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is - * asynchronously completed using the given executor with the - * result of the given function of this and the other given - * CompletableFuture's results when both complete. If this or - * the other CompletableFuture complete exceptionally, then the - * returned CompletableFuture also does so, with a - * CompletionException holding the exception as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when both this and the other given CompletableFuture complete, + * with the result of the given function of the results of the two + * CompletableFutures from a task running in the given executor. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied function throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param fn the function to use to compute the value of @@ -1789,22 +1997,24 @@ public class CompletableFuture implements Future { * @param executor the executor to use for asynchronous execution * @return the new CompletableFuture */ - public CompletableFuture thenCombineAsync(CompletableFuture other, - BiFun fn, - Executor executor) { + public CompletableFuture thenCombineAsync + (CompletableFuture other, + BiFun fn, + Executor executor) { if (executor == null) throw new NullPointerException(); - return doThenBiApply(other, fn, executor); + return doThenCombine(other, fn, executor); } - private CompletableFuture doThenBiApply(CompletableFuture other, - BiFun fn, - Executor e) { + private CompletableFuture doThenCombine + (CompletableFuture other, + BiFun fn, + Executor e) { if (other == null || fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - BiApplyCompletion d = null; + ThenCombine d = null; Object r, s = null; if ((r = result) == null || (s = other.result) == null) { - d = new BiApplyCompletion(this, other, fn, dst, e); + d = new ThenCombine(this, other, fn, dst, e); CompletionNode q = null, p = new CompletionNode(d); while ((r == null && (r = result) == null) || (s == null && (s = other.result) == null)) { @@ -1848,7 +2058,7 @@ public class CompletableFuture implements Future { if (ex == null) { try { if (e != null) - e.execute(new AsyncBiApply(t, u, fn, dst)); + e.execute(new AsyncCombine(t, u, fn, dst)); else v = fn.apply(t, u); } catch (Throwable rex) { @@ -1864,50 +2074,60 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed with - * the results of this and the other given CompletableFuture if - * both complete. If this and/or the other CompletableFuture - * complete exceptionally, then the returned CompletableFuture - * also does so, with a CompletionException holding one of these - * exceptions as its cause. + * Returns a new CompletableFuture that is completed + * when both this and the other given CompletableFuture complete, + * after performing the given action with the results of the two + * CompletableFutures. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied action throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param block the action to perform before completing the * returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture thenAcceptBoth(CompletableFuture other, - BiAction block) { - return doThenBiAccept(other, block, null); + public CompletableFuture thenAcceptBoth + (CompletableFuture other, + BiAction block) { + return doThenAcceptBoth(other, block, null); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the {@link ForkJoinPool#commonPool()} with - * the results of this and the other given CompletableFuture when - * both complete. If this and/or the other CompletableFuture - * complete exceptionally, then the returned CompletableFuture - * also does so, with a CompletionException holding one of these - * exceptions as its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when both this and the other given CompletableFuture complete, + * after performing the given action with the results of the two + * CompletableFutures from a task running in the {@link + * ForkJoinPool#commonPool()}. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied action throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param block the action to perform before completing the * returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture thenAcceptBothAsync(CompletableFuture other, - BiAction block) { - return doThenBiAccept(other, block, ForkJoinPool.commonPool()); + public CompletableFuture thenAcceptBothAsync + (CompletableFuture other, + BiAction block) { + return doThenAcceptBoth(other, block, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the given executor with the results of - * this and the other given CompletableFuture when both complete. - * If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture also does - * so, with a CompletionException holding one of these exceptions as - * its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when both this and the other given CompletableFuture complete, + * after performing the given action with the results of the two + * CompletableFutures from a task running in the given executor. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied action throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param block the action to perform before completing the @@ -1915,22 +2135,24 @@ public class CompletableFuture implements Future { * @param executor the executor to use for asynchronous execution * @return the new CompletableFuture */ - public CompletableFuture thenAcceptBothAsync(CompletableFuture other, - BiAction block, - Executor executor) { + public CompletableFuture thenAcceptBothAsync + (CompletableFuture other, + BiAction block, + Executor executor) { if (executor == null) throw new NullPointerException(); - return doThenBiAccept(other, block, executor); + return doThenAcceptBoth(other, block, executor); } - private CompletableFuture doThenBiAccept(CompletableFuture other, - BiAction fn, - Executor e) { + private CompletableFuture doThenAcceptBoth + (CompletableFuture other, + BiAction fn, + Executor e) { if (other == null || fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - BiAcceptCompletion d = null; + ThenAcceptBoth d = null; Object r, s = null; if ((r = result) == null || (s = other.result) == null) { - d = new BiAcceptCompletion(this, other, fn, dst, e); + d = new ThenAcceptBoth(this, other, fn, dst, e); CompletionNode q = null, p = new CompletionNode(d); while ((r == null && (r = result) == null) || (s == null && (s = other.result) == null)) { @@ -1973,7 +2195,7 @@ public class CompletableFuture implements Future { if (ex == null) { try { if (e != null) - e.execute(new AsyncBiAccept(t, u, fn, dst)); + e.execute(new AsyncAcceptBoth(t, u, fn, dst)); else fn.accept(t, u); } catch (Throwable rex) { @@ -1989,12 +2211,14 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed - * when this and the other given CompletableFuture both - * complete. If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture also does - * so, with a CompletionException holding one of these exceptions as - * its cause. + * Returns a new CompletableFuture that is completed + * when both this and the other given CompletableFuture complete, + * after performing the given action. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied action throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param action the action to perform before completing the @@ -2003,17 +2227,19 @@ public class CompletableFuture implements Future { */ public CompletableFuture runAfterBoth(CompletableFuture other, Runnable action) { - return doThenBiRun(other, action, null); + return doRunAfterBoth(other, action, null); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the {@link ForkJoinPool#commonPool()} - * when this and the other given CompletableFuture both - * complete. If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture also does - * so, with a CompletionException holding one of these exceptions as - * its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when both this and the other given CompletableFuture complete, + * after performing the given action from a task running in the + * {@link ForkJoinPool#commonPool()}. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied action throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param action the action to perform before completing the @@ -2022,17 +2248,19 @@ public class CompletableFuture implements Future { */ public CompletableFuture runAfterBothAsync(CompletableFuture other, Runnable action) { - return doThenBiRun(other, action, ForkJoinPool.commonPool()); + return doRunAfterBoth(other, action, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the given executor - * when this and the other given CompletableFuture both - * complete. If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture also does - * so, with a CompletionException holding one of these exceptions as - * its cause. + * Returns a new CompletableFuture that is asynchronously completed + * when both this and the other given CompletableFuture complete, + * after performing the given action from a task running in the + * given executor. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, or the supplied action throws an exception, + * then the returned CompletableFuture completes exceptionally + * with a CompletionException holding the exception as its cause. * * @param other the other CompletableFuture * @param action the action to perform before completing the @@ -2044,18 +2272,18 @@ public class CompletableFuture implements Future { Runnable action, Executor executor) { if (executor == null) throw new NullPointerException(); - return doThenBiRun(other, action, executor); + return doRunAfterBoth(other, action, executor); } - private CompletableFuture doThenBiRun(CompletableFuture other, - Runnable action, - Executor e) { + private CompletableFuture doRunAfterBoth(CompletableFuture other, + Runnable action, + Executor e) { if (other == null || action == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - BiRunCompletion d = null; + RunAfterBoth d = null; Object r, s = null; if ((r = result) == null || (s = other.result) == null) { - d = new BiRunCompletion(this, other, action, dst, e); + d = new RunAfterBoth(this, other, action, dst, e); CompletionNode q = null, p = new CompletionNode(d); while ((r == null && (r = result) == null) || (s == null && (s = other.result) == null)) { @@ -2101,56 +2329,73 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed with - * the result of the given function of either this or the other - * given CompletableFuture's results when either complete. If - * this and/or the other CompletableFuture complete exceptionally, - * then the returned CompletableFuture may also do so, with a - * CompletionException holding one of these exceptions as its cause. - * No guarantees are made about which result or exception is used - * in the returned CompletableFuture. + * Returns a new CompletableFuture that is completed + * when either this or the other given CompletableFuture completes, + * with the result of the given function of either this or the other + * CompletableFuture's result. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied function + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param fn the function to use to compute the value of * the returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture applyToEither(CompletableFuture other, - Fun fn) { - return doOrApply(other, fn, null); + public CompletableFuture applyToEither + (CompletableFuture other, + Fun fn) { + return doApplyToEither(other, fn, null); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the {@link ForkJoinPool#commonPool()} with - * the result of the given function of either this or the other - * given CompletableFuture's results when either complete. If - * this and/or the other CompletableFuture complete exceptionally, - * then the returned CompletableFuture may also do so, with a - * CompletionException holding one of these exceptions as its cause. - * No guarantees are made about which result or exception is used - * in the returned CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * when either this or the other given CompletableFuture completes, + * with the result of the given function of either this or the other + * CompletableFuture's result from a task running in the + * {@link ForkJoinPool#commonPool()}. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied function + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param fn the function to use to compute the value of * the returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture applyToEitherAsync(CompletableFuture other, - Fun fn) { - return doOrApply(other, fn, ForkJoinPool.commonPool()); + public CompletableFuture applyToEitherAsync + (CompletableFuture other, + Fun fn) { + return doApplyToEither(other, fn, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the given executor with the result of the - * given function of either this or the other given - * CompletableFuture's results when either complete. If this - * and/or the other CompletableFuture complete exceptionally, then - * the returned CompletableFuture may also do so, with a - * CompletionException holding one of these exceptions as its cause. - * No guarantees are made about which result or exception is used - * in the returned CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * when either this or the other given CompletableFuture completes, + * with the result of the given function of either this or the other + * CompletableFuture's result from a task running in the + * given executor. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied function + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param fn the function to use to compute the value of @@ -2158,22 +2403,24 @@ public class CompletableFuture implements Future { * @param executor the executor to use for asynchronous execution * @return the new CompletableFuture */ - public CompletableFuture applyToEitherAsync(CompletableFuture other, - Fun fn, - Executor executor) { + public CompletableFuture applyToEitherAsync + (CompletableFuture other, + Fun fn, + Executor executor) { if (executor == null) throw new NullPointerException(); - return doOrApply(other, fn, executor); + return doApplyToEither(other, fn, executor); } - private CompletableFuture doOrApply(CompletableFuture other, - Fun fn, - Executor e) { + private CompletableFuture doApplyToEither + (CompletableFuture other, + Fun fn, + Executor e) { if (other == null || fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - OrApplyCompletion d = null; + ApplyToEither d = null; Object r; if ((r = result) == null && (r = other.result) == null) { - d = new OrApplyCompletion(this, other, fn, dst, e); + d = new ApplyToEither(this, other, fn, dst, e); CompletionNode q = null, p = new CompletionNode(d); while ((r = result) == null && (r = other.result) == null) { if (q != null) { @@ -2217,56 +2464,73 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed after - * performing the given action with the result of either this or the - * other given CompletableFuture's result, when either complete. - * If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture may also do - * so, with a CompletionException holding one of these exceptions as - * its cause. No guarantees are made about which exception is - * used in the returned CompletableFuture. + * Returns a new CompletableFuture that is completed + * when either this or the other given CompletableFuture completes, + * after performing the given action with the result of either this + * or the other CompletableFuture's result. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied action + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param block the action to perform before completing the * returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture acceptEither(CompletableFuture other, - Action block) { - return doOrAccept(other, block, null); + public CompletableFuture acceptEither + (CompletableFuture other, + Action block) { + return doAcceptEither(other, block, null); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the {@link ForkJoinPool#commonPool()}, - * performing the given action with the result of either this or - * the other given CompletableFuture's result, when either - * complete. If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture may also do - * so, with a CompletionException holding one of these exceptions as - * its cause. No guarantees are made about which exception is - * used in the returned CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * when either this or the other given CompletableFuture completes, + * after performing the given action with the result of either this + * or the other CompletableFuture's result from a task running in + * the {@link ForkJoinPool#commonPool()}. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied action + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param block the action to perform before completing the * returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture acceptEitherAsync(CompletableFuture other, - Action block) { - return doOrAccept(other, block, ForkJoinPool.commonPool()); + public CompletableFuture acceptEitherAsync + (CompletableFuture other, + Action block) { + return doAcceptEither(other, block, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the given executor, - * performing the given action with the result of either this or - * the other given CompletableFuture's result, when either - * complete. If this and/or the other CompletableFuture complete - * exceptionally, then the returned CompletableFuture may also do - * so, with a CompletionException holding one of these exceptions as - * its cause. No guarantees are made about which exception is - * used in the returned CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * when either this or the other given CompletableFuture completes, + * after performing the given action with the result of either this + * or the other CompletableFuture's result from a task running in + * the given executor. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied action + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param block the action to perform before completing the @@ -2274,22 +2538,24 @@ public class CompletableFuture implements Future { * @param executor the executor to use for asynchronous execution * @return the new CompletableFuture */ - public CompletableFuture acceptEitherAsync(CompletableFuture other, - Action block, - Executor executor) { + public CompletableFuture acceptEitherAsync + (CompletableFuture other, + Action block, + Executor executor) { if (executor == null) throw new NullPointerException(); - return doOrAccept(other, block, executor); + return doAcceptEither(other, block, executor); } - private CompletableFuture doOrAccept(CompletableFuture other, - Action fn, - Executor e) { + private CompletableFuture doAcceptEither + (CompletableFuture other, + Action fn, + Executor e) { if (other == null || fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - OrAcceptCompletion d = null; + AcceptEither d = null; Object r; if ((r = result) == null && (r = other.result) == null) { - d = new OrAcceptCompletion(this, other, fn, dst, e); + d = new AcceptEither(this, other, fn, dst, e); CompletionNode q = null, p = new CompletionNode(d); while ((r = result) == null && (r = other.result) == null) { if (q != null) { @@ -2332,13 +2598,18 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed - * after this or the other given CompletableFuture complete. If - * this and/or the other CompletableFuture complete exceptionally, - * then the returned CompletableFuture may also do so, with a - * CompletionException holding one of these exceptions as its cause. - * No guarantees are made about which exception is used in the - * returned CompletableFuture. + * Returns a new CompletableFuture that is completed + * when either this or the other given CompletableFuture completes, + * after performing the given action. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied action + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param action the action to perform before completing the @@ -2347,38 +2618,49 @@ public class CompletableFuture implements Future { */ public CompletableFuture runAfterEither(CompletableFuture other, Runnable action) { - return doOrRun(other, action, null); + return doRunAfterEither(other, action, null); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the {@link ForkJoinPool#commonPool()} - * after this or the other given CompletableFuture complete. If - * this and/or the other CompletableFuture complete exceptionally, - * then the returned CompletableFuture may also do so, with a - * CompletionException holding one of these exceptions as its cause. - * No guarantees are made about which exception is used in the - * returned CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * when either this or the other given CompletableFuture completes, + * after performing the given action from a task running in the + * {@link ForkJoinPool#commonPool()}. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied action + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param action the action to perform before completing the * returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture runAfterEitherAsync(CompletableFuture other, - Runnable action) { - return doOrRun(other, action, ForkJoinPool.commonPool()); + public CompletableFuture runAfterEitherAsync + (CompletableFuture other, + Runnable action) { + return doRunAfterEither(other, action, ForkJoinPool.commonPool()); } /** - * Creates and returns a CompletableFuture that is completed - * asynchronously using the given executor after this or the other - * given CompletableFuture complete. If this and/or the other - * CompletableFuture complete exceptionally, then the returned - * CompletableFuture may also do so, with a CompletionException - * holding one of these exceptions as its cause. No guarantees are - * made about which exception is used in the returned - * CompletableFuture. + * Returns a new CompletableFuture that is asynchronously completed + * when either this or the other given CompletableFuture completes, + * after performing the given action from a task running in the + * given executor. + * + *

If this and/or the other CompletableFuture complete + * exceptionally, then the returned CompletableFuture may also do so, + * with a CompletionException holding one of these exceptions as its + * cause. No guarantees are made about which result or exception is + * used in the returned CompletableFuture. If the supplied action + * throws an exception, then the returned CompletableFuture completes + * exceptionally with a CompletionException holding the exception as + * its cause. * * @param other the other CompletableFuture * @param action the action to perform before completing the @@ -2386,22 +2668,24 @@ public class CompletableFuture implements Future { * @param executor the executor to use for asynchronous execution * @return the new CompletableFuture */ - public CompletableFuture runAfterEitherAsync(CompletableFuture other, - Runnable action, - Executor executor) { + public CompletableFuture runAfterEitherAsync + (CompletableFuture other, + Runnable action, + Executor executor) { if (executor == null) throw new NullPointerException(); - return doOrRun(other, action, executor); + return doRunAfterEither(other, action, executor); } - private CompletableFuture doOrRun(CompletableFuture other, - Runnable action, - Executor e) { + private CompletableFuture doRunAfterEither + (CompletableFuture other, + Runnable action, + Executor e) { if (other == null || action == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); - OrRunCompletion d = null; + RunAfterEither d = null; Object r; if ((r = result) == null && (r = other.result) == null) { - d = new OrRunCompletion(this, other, action, dst, e); + d = new RunAfterEither(this, other, action, dst, e); CompletionNode q = null, p = new CompletionNode(d); while ((r = result) == null && (r = other.result) == null) { if (q != null) { @@ -2439,27 +2723,77 @@ public class CompletableFuture implements Future { } /** - * Returns a CompletableFuture (or an equivalent one) produced by - * the given function of the result of this CompletableFuture when - * completed. If this CompletableFuture completes exceptionally, - * then the returned CompletableFuture also does so, with a + * Returns a CompletableFuture that upon completion, has the same + * value as produced by the given function of the result of this + * CompletableFuture. + * + *

If this CompletableFuture completes exceptionally, then the + * returned CompletableFuture also does so, with a * CompletionException holding this exception as its cause. + * Similarly, if the computed CompletableFuture completes + * exceptionally, then so does the returned CompletableFuture. * * @param fn the function returning a new CompletableFuture - * @return the CompletableFuture, that {@code isDone()} upon - * return if completed by the given function, or an exception - * occurs + * @return the CompletableFuture */ - public CompletableFuture thenCompose(Fun> fn) { + public CompletableFuture thenCompose + (Fun> fn) { + return doThenCompose(fn, null); + } + + /** + * Returns a CompletableFuture that upon completion, has the same + * value as that produced asynchronously using the {@link + * ForkJoinPool#commonPool()} by the given function of the result + * of this CompletableFuture. + * + *

If this CompletableFuture completes exceptionally, then the + * returned CompletableFuture also does so, with a + * CompletionException holding this exception as its cause. + * Similarly, if the computed CompletableFuture completes + * exceptionally, then so does the returned CompletableFuture. + * + * @param fn the function returning a new CompletableFuture + * @return the CompletableFuture + */ + public CompletableFuture thenComposeAsync + (Fun> fn) { + return doThenCompose(fn, ForkJoinPool.commonPool()); + } + + /** + * Returns a CompletableFuture that upon completion, has the same + * value as that produced asynchronously using the given executor + * by the given function of this CompletableFuture. + * + *

If this CompletableFuture completes exceptionally, then the + * returned CompletableFuture also does so, with a + * CompletionException holding this exception as its cause. + * Similarly, if the computed CompletableFuture completes + * exceptionally, then so does the returned CompletableFuture. + * + * @param fn the function returning a new CompletableFuture + * @param executor the executor to use for asynchronous execution + * @return the CompletableFuture + */ + public CompletableFuture thenComposeAsync + (Fun> fn, + Executor executor) { + if (executor == null) throw new NullPointerException(); + return doThenCompose(fn, executor); + } + + private CompletableFuture doThenCompose + (Fun> fn, + Executor e) { if (fn == null) throw new NullPointerException(); CompletableFuture dst = null; - ComposeCompletion d = null; + ThenCompose d = null; Object r; if ((r = result) == null) { dst = new CompletableFuture(); CompletionNode p = new CompletionNode - (d = new ComposeCompletion(this, fn, dst)); + (d = new ThenCompose(this, fn, dst, e)); while ((r = result) == null) { if (UNSAFE.compareAndSwapObject (this, COMPLETIONS, p.next = completions, p)) @@ -2478,18 +2812,23 @@ public class CompletableFuture implements Future { t = tr; } if (ex == null) { - try { - dst = fn.apply(t); - } catch (Throwable rex) { - ex = rex; + if (e != null) { + if (dst == null) + dst = new CompletableFuture(); + e.execute(new AsyncCompose(t, fn, dst)); + } + else { + try { + if ((dst = fn.apply(t)) == null) + ex = new NullPointerException(); + } catch (Throwable rex) { + ex = rex; + } } } - if (dst == null) { + if (dst == null) dst = new CompletableFuture(); - if (ex == null) - ex = new NullPointerException(); - } - if (ex != null) + if (e == null || ex != null) dst.internalComplete(null, ex); } helpPostComplete(); @@ -2498,19 +2837,20 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed with - * the result of the given function of the exception triggering - * this CompletableFuture's completion when it completes - * exceptionally; Otherwise, if this CompletableFuture completes - * normally, then the returned CompletableFuture also completes - * normally with the same value. + * Returns a new CompletableFuture that is completed when this + * CompletableFuture completes, with the result of the given + * function of the exception triggering this CompletableFuture's + * completion when it completes exceptionally; otherwise, if this + * CompletableFuture completes normally, then the returned + * CompletableFuture also completes normally with the same value. * * @param fn the function to use to compute the value of the * returned CompletableFuture if this CompletableFuture completed * exceptionally * @return the new CompletableFuture */ - public CompletableFuture exceptionally(Fun fn) { + public CompletableFuture exceptionally + (Fun fn) { if (fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); ExceptionCompletion d = null; @@ -2527,7 +2867,7 @@ public class CompletableFuture implements Future { if (r != null && (d == null || d.compareAndSet(0, 1))) { T t = null; Throwable ex, dx = null; if (r instanceof AltResult) { - if ((ex = ((AltResult)r).ex) != null) { + if ((ex = ((AltResult)r).ex) != null) { try { t = fn.apply(ex); } catch (Throwable rex) { @@ -2546,18 +2886,19 @@ public class CompletableFuture implements Future { } /** - * Creates and returns a CompletableFuture that is completed with - * the result of the given function of the result and exception of - * this CompletableFuture's completion when it completes. The - * given function is invoked with the result (or {@code null} if - * none) and the exception (or {@code null} if none) of this - * CompletableFuture when complete. + * Returns a new CompletableFuture that is completed when this + * CompletableFuture completes, with the result of the given + * function of the result and exception of this CompletableFuture's + * completion. The given function is invoked with the result (or + * {@code null} if none) and the exception (or {@code null} if none) + * of this CompletableFuture when complete. * * @param fn the function to use to compute the value of the * returned CompletableFuture * @return the new CompletableFuture */ - public CompletableFuture handle(BiFun fn) { + public CompletableFuture handle + (BiFun fn) { if (fn == null) throw new NullPointerException(); CompletableFuture dst = new CompletableFuture(); HandleCompletion d = null; @@ -2596,9 +2937,230 @@ public class CompletableFuture implements Future { return dst; } + + /* ------------- Arbitrary-arity constructions -------------- */ + + /* + * The basic plan of attack is to recursively form binary + * completion trees of elements. This can be overkill for small + * sets, but scales nicely. The And/All vs Or/Any forms use the + * same idea, but details differ. + */ + /** - * Attempts to complete this CompletableFuture with - * a {@link CancellationException}. + * Returns a new CompletableFuture that is completed when all of + * the given CompletableFutures complete. If any of the given + * CompletableFutures complete exceptionally, then the returned + * CompletableFuture also does so, with a CompletionException + * holding this exception as its cause. Otherwise, the results, + * if any, of the given CompletableFutures are not reflected in + * the returned CompletableFuture, but may be obtained by + * inspecting them individually. If no CompletableFutures are + * provided, returns a CompletableFuture completed with the value + * {@code null}. + * + *

Among the applications of this method is to await completion + * of a set of independent CompletableFutures before continuing a + * program, as in: {@code CompletableFuture.allOf(c1, c2, + * c3).join();}. + * + * @param cfs the CompletableFutures + * @return a new CompletableFuture that is completed when all of the + * given CompletableFutures complete + * @throws NullPointerException if the array or any of its elements are + * {@code null} + */ + public static CompletableFuture allOf(CompletableFuture... cfs) { + int len = cfs.length; // Directly handle empty and singleton cases + if (len > 1) + return allTree(cfs, 0, len - 1); + else { + CompletableFuture dst = new CompletableFuture(); + CompletableFuture f; + if (len == 0) + dst.result = NIL; + else if ((f = cfs[0]) == null) + throw new NullPointerException(); + else { + ThenPropagate d = null; + CompletionNode p = null; + Object r; + while ((r = f.result) == null) { + if (d == null) + d = new ThenPropagate(f, dst); + else if (p == null) + p = new CompletionNode(d); + else if (UNSAFE.compareAndSwapObject + (f, COMPLETIONS, p.next = f.completions, p)) + break; + } + if (r != null && (d == null || d.compareAndSet(0, 1))) + dst.internalComplete(null, (r instanceof AltResult) ? + ((AltResult)r).ex : null); + f.helpPostComplete(); + } + return dst; + } + } + + /** + * Recursively constructs an And'ed tree of CompletableFutures. + * Called only when array known to have at least two elements. + */ + private static CompletableFuture allTree(CompletableFuture[] cfs, + int lo, int hi) { + CompletableFuture fst, snd; + int mid = (lo + hi) >>> 1; + if ((fst = (lo == mid ? cfs[lo] : allTree(cfs, lo, mid))) == null || + (snd = (hi == mid+1 ? cfs[hi] : allTree(cfs, mid+1, hi))) == null) + throw new NullPointerException(); + CompletableFuture dst = new CompletableFuture(); + AndCompletion d = null; + CompletionNode p = null, q = null; + Object r = null, s = null; + while ((r = fst.result) == null || (s = snd.result) == null) { + if (d == null) + d = new AndCompletion(fst, snd, dst); + else if (p == null) + p = new CompletionNode(d); + else if (q == null) { + if (UNSAFE.compareAndSwapObject + (fst, COMPLETIONS, p.next = fst.completions, p)) + q = new CompletionNode(d); + } + else if (UNSAFE.compareAndSwapObject + (snd, COMPLETIONS, q.next = snd.completions, q)) + break; + } + if ((r != null || (r = fst.result) != null) && + (s != null || (s = snd.result) != null) && + (d == null || d.compareAndSet(0, 1))) { + Throwable ex; + if (r instanceof AltResult) + ex = ((AltResult)r).ex; + else + ex = null; + if (ex == null && (s instanceof AltResult)) + ex = ((AltResult)s).ex; + dst.internalComplete(null, ex); + } + fst.helpPostComplete(); + snd.helpPostComplete(); + return dst; + } + + /** + * Returns a new CompletableFuture that is completed when any of + * the given CompletableFutures complete, with the same result. + * Otherwise, if it completed exceptionally, the returned + * CompletableFuture also does so, with a CompletionException + * holding this exception as its cause. If no CompletableFutures + * are provided, returns an incomplete CompletableFuture. + * + * @param cfs the CompletableFutures + * @return a new CompletableFuture that is completed with the + * result or exception of any of the given CompletableFutures when + * one completes + * @throws NullPointerException if the array or any of its elements are + * {@code null} + */ + public static CompletableFuture anyOf(CompletableFuture... cfs) { + int len = cfs.length; // Same idea as allOf + if (len > 1) + return anyTree(cfs, 0, len - 1); + else { + CompletableFuture dst = new CompletableFuture(); + CompletableFuture f; + if (len == 0) + ; // skip + else if ((f = cfs[0]) == null) + throw new NullPointerException(); + else { + ThenCopy d = null; + CompletionNode p = null; + Object r; + while ((r = f.result) == null) { + if (d == null) + d = new ThenCopy(f, dst); + else if (p == null) + p = new CompletionNode(d); + else if (UNSAFE.compareAndSwapObject + (f, COMPLETIONS, p.next = f.completions, p)) + break; + } + if (r != null && (d == null || d.compareAndSet(0, 1))) { + Throwable ex; Object t; + if (r instanceof AltResult) { + ex = ((AltResult)r).ex; + t = null; + } + else { + ex = null; + t = r; + } + dst.internalComplete(t, ex); + } + f.helpPostComplete(); + } + return dst; + } + } + + /** + * Recursively constructs an Or'ed tree of CompletableFutures. + */ + private static CompletableFuture anyTree(CompletableFuture[] cfs, + int lo, int hi) { + CompletableFuture fst, snd; + int mid = (lo + hi) >>> 1; + if ((fst = (lo == mid ? cfs[lo] : anyTree(cfs, lo, mid))) == null || + (snd = (hi == mid+1 ? cfs[hi] : anyTree(cfs, mid+1, hi))) == null) + throw new NullPointerException(); + CompletableFuture dst = new CompletableFuture(); + OrCompletion d = null; + CompletionNode p = null, q = null; + Object r; + while ((r = fst.result) == null && (r = snd.result) == null) { + if (d == null) + d = new OrCompletion(fst, snd, dst); + else if (p == null) + p = new CompletionNode(d); + else if (q == null) { + if (UNSAFE.compareAndSwapObject + (fst, COMPLETIONS, p.next = fst.completions, p)) + q = new CompletionNode(d); + } + else if (UNSAFE.compareAndSwapObject + (snd, COMPLETIONS, q.next = snd.completions, q)) + break; + } + if ((r != null || (r = fst.result) != null || + (r = snd.result) != null) && + (d == null || d.compareAndSet(0, 1))) { + Throwable ex; Object t; + if (r instanceof AltResult) { + ex = ((AltResult)r).ex; + t = null; + } + else { + ex = null; + t = r; + } + dst.internalComplete(t, ex); + } + fst.helpPostComplete(); + snd.helpPostComplete(); + return dst; + } + + /* ------------- Control and status methods -------------- */ + + /** + * If not already completed, completes this CompletableFuture with + * a {@link CancellationException}. Dependent CompletableFutures + * that have not already completed will also complete + * exceptionally, with a {@link CompletionException} caused by + * this {@code CancellationException}. * * @param mayInterruptIfRunning this value has no effect in this * implementation because interrupts are not used to control @@ -2607,16 +3169,11 @@ public class CompletableFuture implements Future { * @return {@code true} if this task is now cancelled */ public boolean cancel(boolean mayInterruptIfRunning) { - Object r; - while ((r = result) == null) { - r = new AltResult(new CancellationException()); - if (UNSAFE.compareAndSwapObject(this, RESULT, null, r)) { - postComplete(); - return true; - } - } - return ((r instanceof AltResult) && - (((AltResult)r).ex instanceof CancellationException)); + boolean cancelled = (result == null) && + UNSAFE.compareAndSwapObject + (this, RESULT, null, new AltResult(new CancellationException())); + postComplete(); + return cancelled || isCancelled(); } /** @@ -2663,6 +3220,44 @@ public class CompletableFuture implements Future { postComplete(); } + /** + * Returns the estimated number of CompletableFutures whose + * completions are awaiting completion of this CompletableFuture. + * This method is designed for use in monitoring system state, not + * for synchronization control. + * + * @return the number of dependent CompletableFutures + */ + public int getNumberOfDependents() { + int count = 0; + for (CompletionNode p = completions; p != null; p = p.next) + ++count; + return count; + } + + /** + * Returns a string identifying this CompletableFuture, as well as + * its completion state. The state, in brackets, contains the + * String {@code "Completed Normally"} or the String {@code + * "Completed Exceptionally"}, or the String {@code "Not + * completed"} followed by the number of CompletableFutures + * dependent upon its completion, if any. + * + * @return a string identifying this CompletableFuture, as well as its state + */ + public String toString() { + Object r = result; + int count; + return super.toString() + + ((r == null) ? + (((count = getNumberOfDependents()) == 0) ? + "[Not completed]" : + "[Not completed, " + count + " dependents]") : + (((r instanceof AltResult) && ((AltResult)r).ex != null) ? + "[Completed exceptionally]" : + "[Completed normally]")); + } + // Unsafe mechanics private static final sun.misc.Unsafe UNSAFE; private static final long RESULT; @@ -2683,7 +3278,6 @@ public class CompletableFuture implements Future { } } - /** * Returns a sun.misc.Unsafe. Suitable for use in a 3rd party package. * Replace with a simple call to Unsafe.getUnsafe when integrating diff --git a/src/main/java/jsr166e/ConcurrentHashMapV8.java b/src/main/java/jsr166e/ConcurrentHashMapV8.java index eb307bdb155..5706cd04d76 100644 --- a/src/main/java/jsr166e/ConcurrentHashMapV8.java +++ b/src/main/java/jsr166e/ConcurrentHashMapV8.java @@ -6,25 +6,28 @@ package jsr166e; -import java.util.Comparator; -import java.util.Arrays; -import java.util.Map; -import java.util.Set; -import java.util.Collection; -import java.util.AbstractMap; -import java.util.AbstractSet; -import java.util.AbstractCollection; -import java.util.Hashtable; -import java.util.HashMap; -import java.util.Iterator; -import java.util.Enumeration; -import java.util.ConcurrentModificationException; -import java.util.NoSuchElementException; -import java.util.concurrent.ConcurrentMap; -import java.util.concurrent.locks.AbstractQueuedSynchronizer; -import java.util.concurrent.atomic.AtomicInteger; -import java.util.concurrent.atomic.AtomicReference; +import jsr166e.ForkJoinPool; + +import java.io.ObjectStreamField; import java.io.Serializable; +import java.lang.reflect.ParameterizedType; +import java.lang.reflect.Type; +import java.util.Arrays; +import java.util.Collection; +import java.util.Comparator; +import java.util.ConcurrentModificationException; +import java.util.Enumeration; +import java.util.HashMap; +import java.util.Hashtable; +import java.util.Iterator; +import java.util.Map; +import java.util.NoSuchElementException; +import java.util.Set; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.atomic.AtomicReference; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.locks.LockSupport; +import java.util.concurrent.locks.ReentrantLock; /** * A hash table supporting full concurrency of retrievals and @@ -78,7 +81,8 @@ import java.io.Serializable; * expected {@code concurrencyLevel} as an additional hint for * internal sizing. Note that using many keys with exactly the same * {@code hashCode()} is a sure way to slow down performance of any - * hash table. + * hash table. To ameliorate impact, when keys are {@link Comparable}, + * this class may use comparison order among keys to help break ties. * *

A {@link Set} projection of a ConcurrentHashMapV8 may be created * (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed @@ -86,13 +90,6 @@ import java.io.Serializable; * mapped values are (perhaps transiently) not used or all take the * same mapping value. * - *

A ConcurrentHashMapV8 can be used as scalable frequency map (a - * form of histogram or multiset) by using {@link LongAdder} values - * and initializing via {@link #computeIfAbsent}. For example, to add - * a count to a {@code ConcurrentHashMapV8 freqs}, you - * can use {@code freqs.computeIfAbsent(k -> new - * LongAdder()).increment();} - * *

This class and its views and iterators implement all of the * optional methods of the {@link Map} and {@link Iterator} * interfaces. @@ -100,23 +97,21 @@ import java.io.Serializable; *

Like {@link Hashtable} but unlike {@link HashMap}, this class * does not allow {@code null} to be used as a key or value. * - *

ConcurrentHashMapV8s support sequential and parallel operations - * bulk operations. (Parallel forms use the {@link - * ForkJoinPool#commonPool()}). Tasks that may be used in other - * contexts are available in class {@link ForkJoinTasks}. These - * operations are designed to be safely, and often sensibly, applied - * even with maps that are being concurrently updated by other - * threads; for example, when computing a snapshot summary of the - * values in a shared registry. There are three kinds of operation, - * each with four forms, accepting functions with Keys, Values, - * Entries, and (Key, Value) arguments and/or return values. Because - * the elements of a ConcurrentHashMapV8 are not ordered in any - * particular way, and may be processed in different orders in - * different parallel executions, the correctness of supplied - * functions should not depend on any ordering, or on any other - * objects or values that may transiently change while computation is - * in progress; and except for forEach actions, should ideally be - * side-effect-free. + *

ConcurrentHashMapV8s support a set of sequential and parallel bulk + * operations that are designed + * to be safely, and often sensibly, applied even with maps that are + * being concurrently updated by other threads; for example, when + * computing a snapshot summary of the values in a shared registry. + * There are three kinds of operation, each with four forms, accepting + * functions with Keys, Values, Entries, and (Key, Value) arguments + * and/or return values. Because the elements of a ConcurrentHashMapV8 + * are not ordered in any particular way, and may be processed in + * different orders in different parallel executions, the correctness + * of supplied functions should not depend on any ordering, or on any + * other objects or values that may transiently change while + * computation is in progress; and except for forEach actions, should + * ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry} + * objects do not support method {@code setValue}. * *

    *
  • forEach: Perform a given action on each element. @@ -143,9 +138,20 @@ import java.io.Serializable; *
  • Reductions to scalar doubles, longs, and ints, using a * given basis value.
    • * + *
* * - * + * + *

These bulk operations accept a {@code parallelismThreshold} + * argument. Methods proceed sequentially if the current map size is + * estimated to be less than the given threshold. Using a value of + * {@code Long.MAX_VALUE} suppresses all parallelism. Using a value + * of {@code 1} results in maximal parallelism by partitioning into + * enough subtasks to fully utilize the {@link + * ForkJoinPool#commonPool()} that is used for all parallel + * computations. Normally, you would initially choose one of these + * extreme values, and then measure performance of using in-between + * values that trade off overhead versus throughput. * *

The concurrency properties of bulk operations follow * from those of ConcurrentHashMapV8: Any non-null result returned @@ -217,74 +223,58 @@ public class ConcurrentHashMapV8 private static final long serialVersionUID = 7249069246763182397L; /** - * A partitionable iterator. A Spliterator can be traversed - * directly, but can also be partitioned (before traversal) by - * creating another Spliterator that covers a non-overlapping - * portion of the elements, and so may be amenable to parallel - * execution. - * - *

This interface exports a subset of expected JDK8 - * functionality. - * - *

Sample usage: Here is one (of the several) ways to compute - * the sum of the values held in a map using the ForkJoin - * framework. As illustrated here, Spliterators are well suited to - * designs in which a task repeatedly splits off half its work - * into forked subtasks until small enough to process directly, - * and then joins these subtasks. Variants of this style can also - * be used in completion-based designs. - * - * 

-     * {@code ConcurrentHashMapV8 m = ...
-     * // split as if have 8 * parallelism, for load balance
-     * int n = m.size();
-     * int p = aForkJoinPool.getParallelism() * 8;
-     * int split = (n < p)? n : p;
-     * long sum = aForkJoinPool.invoke(new SumValues(m.valueSpliterator(), split, null));
-     * // ...
-     * static class SumValues extends RecursiveTask {
-     *   final Spliterator s;
-     *   final int split;             // split while > 1
-     *   final SumValues nextJoin;    // records forked subtasks to join
-     *   SumValues(Spliterator s, int depth, SumValues nextJoin) {
-     *     this.s = s; this.depth = depth; this.nextJoin = nextJoin;
-     *   }
-     *   public Long compute() {
-     *     long sum = 0;
-     *     SumValues subtasks = null; // fork subtasks
-     *     for (int s = split >>> 1; s > 0; s >>>= 1)
-     *       (subtasks = new SumValues(s.split(), s, subtasks)).fork();
-     *     while (s.hasNext())        // directly process remaining elements
-     *       sum += s.next();
-     *     for (SumValues t = subtasks; t != null; t = t.nextJoin)
-     *       sum += t.join();         // collect subtask results
-     *     return sum;
-     *   }
-     * }
-     * }
+ * An object for traversing and partitioning elements of a source. + * This interface provides a subset of the functionality of JDK8 + * java.util.Spliterator. */ - public static interface Spliterator extends Iterator { + public static interface ConcurrentHashMapSpliterator { /** - * Returns a Spliterator covering approximately half of the - * elements, guaranteed not to overlap with those subsequently - * returned by this Spliterator. After invoking this method, - * the current Spliterator will not produce any of - * the elements of the returned Spliterator, but the two - * Spliterators together will produce all of the elements that - * would have been produced by this Spliterator had this - * method not been called. The exact number of elements - * produced by the returned Spliterator is not guaranteed, and - * may be zero (i.e., with {@code hasNext()} reporting {@code - * false}) if this Spliterator cannot be further split. - * - * @return a Spliterator covering approximately half of the - * elements - * @throws IllegalStateException if this Spliterator has - * already commenced traversing elements + * If possible, returns a new spliterator covering + * approximately one half of the elements, which will not be + * covered by this spliterator. Returns null if cannot be + * split. */ - Spliterator split(); + ConcurrentHashMapSpliterator trySplit(); + /** + * Returns an estimate of the number of elements covered by + * this Spliterator. + */ + long estimateSize(); + + /** Applies the action to each untraversed element */ + void forEachRemaining(Action action); + /** If an element remains, applies the action and returns true. */ + boolean tryAdvance(Action action); } + // Sams + /** Interface describing a void action of one argument */ + public interface Action { void apply(A a); } + /** Interface describing a void action of two arguments */ + public interface BiAction { void apply(A a, B b); } + /** Interface describing a function of one argument */ + public interface Fun { T apply(A a); } + /** Interface describing a function of two arguments */ + public interface BiFun { T apply(A a, B b); } + /** Interface describing a function mapping its argument to a double */ + public interface ObjectToDouble { double apply(A a); } + /** Interface describing a function mapping its argument to a long */ + public interface ObjectToLong { long apply(A a); } + /** Interface describing a function mapping its argument to an int */ + public interface ObjectToInt {int apply(A a); } + /** Interface describing a function mapping two arguments to a double */ + public interface ObjectByObjectToDouble { double apply(A a, B b); } + /** Interface describing a function mapping two arguments to a long */ + public interface ObjectByObjectToLong { long apply(A a, B b); } + /** Interface describing a function mapping two arguments to an int */ + public interface ObjectByObjectToInt {int apply(A a, B b); } + /** Interface describing a function mapping two doubles to a double */ + public interface DoubleByDoubleToDouble { double apply(double a, double b); } + /** Interface describing a function mapping two longs to a long */ + public interface LongByLongToLong { long apply(long a, long b); } + /** Interface describing a function mapping two ints to an int */ + public interface IntByIntToInt { int apply(int a, int b); } + /* * Overview: * @@ -295,16 +285,21 @@ public class ConcurrentHashMapV8 * the same or better than java.util.HashMap, and to support high * initial insertion rates on an empty table by many threads. * - * Each key-value mapping is held in a Node. Because Node key - * fields can contain special values, they are defined using plain - * Object types (not type "K"). This leads to a lot of explicit - * casting (and many explicit warning suppressions to tell - * compilers not to complain about it). It also allows some of the - * public methods to be factored into a smaller number of internal - * methods (although sadly not so for the five variants of - * put-related operations). The validation-based approach - * explained below leads to a lot of code sprawl because - * retry-control precludes factoring into smaller methods. + * This map usually acts as a binned (bucketed) hash table. Each + * key-value mapping is held in a Node. Most nodes are instances + * of the basic Node class with hash, key, value, and next + * fields. However, various subclasses exist: TreeNodes are + * arranged in balanced trees, not lists. TreeBins hold the roots + * of sets of TreeNodes. ForwardingNodes are placed at the heads + * of bins during resizing. ReservationNodes are used as + * placeholders while establishing values in computeIfAbsent and + * related methods. The types TreeBin, ForwardingNode, and + * ReservationNode do not hold normal user keys, values, or + * hashes, and are readily distinguishable during search etc + * because they have negative hash fields and null key and value + * fields. (These special nodes are either uncommon or transient, + * so the impact of carrying around some unused fields is + * insignificant.) * * The table is lazily initialized to a power-of-two size upon the * first insertion. Each bin in the table normally contains a @@ -312,17 +307,12 @@ public class ConcurrentHashMapV8 * Table accesses require volatile/atomic reads, writes, and * CASes. Because there is no other way to arrange this without * adding further indirections, we use intrinsics - * (sun.misc.Unsafe) operations. The lists of nodes within bins - * are always accurately traversable under volatile reads, so long - * as lookups check hash code and non-nullness of value before - * checking key equality. + * (sun.misc.Unsafe) operations. * * We use the top (sign) bit of Node hash fields for control * purposes -- it is available anyway because of addressing - * constraints. Nodes with negative hash fields are forwarding - * nodes to either TreeBins or resized tables. The lower 31 bits - * of each normal Node's hash field contain a transformation of - * the key's hash code. + * constraints. Nodes with negative hash fields are specially + * handled or ignored in map methods. * * Insertion (via put or its variants) of the first node in an * empty bin is performed by just CASing it to the bin. This is @@ -339,10 +329,7 @@ public class ConcurrentHashMapV8 * validate that it is still the first node after locking it, and * retry if not. Because new nodes are always appended to lists, * once a node is first in a bin, it remains first until deleted - * or the bin becomes invalidated (upon resizing). However, - * operations that only conditionally update may inspect nodes - * until the point of update. This is a converse of sorts to the - * lazy locking technique described by Herlihy & Shavit. + * or the bin becomes invalidated (upon resizing). * * The main disadvantage of per-bin locks is that other update * operations on other nodes in a bin list protected by the same @@ -375,15 +362,12 @@ public class ConcurrentHashMapV8 * sometimes deviate significantly from uniform randomness. This * includes the case when N > (1<<30), so some keys MUST collide. * Similarly for dumb or hostile usages in which multiple keys are - * designed to have identical hash codes. Also, although we guard - * against the worst effects of this (see method spread), sets of - * hashes may differ only in bits that do not impact their bin - * index for a given power-of-two mask. So we use a secondary - * strategy that applies when the number of nodes in a bin exceeds - * a threshold, and at least one of the keys implements - * Comparable. These TreeBins use a balanced tree to hold nodes - * (a specialized form of red-black trees), bounding search time - * to O(log N). Each search step in a TreeBin is around twice as + * designed to have identical hash codes or ones that differs only + * in masked-out high bits. So we use a secondary strategy that + * applies when the number of nodes in a bin exceeds a + * threshold. These TreeBins use a balanced tree to hold nodes (a + * specialized form of red-black trees), bounding search time to + * O(log N). Each search step in a TreeBin is at least twice as * slow as in a regular list, but given that N cannot exceed * (1<<64) (before running out of addresses) this bounds search * steps, lock hold times, etc, to reasonable constants (roughly @@ -456,9 +440,41 @@ public class ConcurrentHashMapV8 * bin already holding two or more nodes. Under uniform hash * distributions, the probability of this occurring at threshold * is around 13%, meaning that only about 1 in 8 puts check - * threshold (and after resizing, many fewer do so). The bulk - * putAll operation further reduces contention by only committing - * count updates upon these size checks. + * threshold (and after resizing, many fewer do so). + * + * TreeBins use a special form of comparison for search and + * related operations (which is the main reason we cannot use + * existing collections such as TreeMaps). TreeBins contain + * Comparable elements, but may contain others, as well as + * elements that are Comparable but not necessarily Comparable + * for the same T, so we cannot invoke compareTo among them. To + * handle this, the tree is ordered primarily by hash value, then + * by Comparable.compareTo order if applicable. On lookup at a + * node, if elements are not comparable or compare as 0 then both + * left and right children may need to be searched in the case of + * tied hash values. (This corresponds to the full list search + * that would be necessary if all elements were non-Comparable and + * had tied hashes.) The red-black balancing code is updated from + * pre-jdk-collections + * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java) + * based in turn on Cormen, Leiserson, and Rivest "Introduction to + * Algorithms" (CLR). + * + * TreeBins also require an additional locking mechanism. While + * list traversal is always possible by readers even during + * updates, tree traversal is not, mainly because of tree-rotations + * that may change the root node and/or its linkages. TreeBins + * include a simple read-write lock mechanism parasitic on the + * main bin-synchronization strategy: Structural adjustments + * associated with an insertion or removal are already bin-locked + * (and so cannot conflict with other writers) but must wait for + * ongoing readers to finish. Since there can be only one such + * waiter, we use a simple scheme using a single "waiter" field to + * block writers. However, readers need never block. If the root + * lock is held, they proceed along the slow traversal path (via + * next-pointers) until the lock becomes available or the list is + * exhausted, whichever comes first. These cases are not fast, but + * maximize aggregate expected throughput. * * Maintaining API and serialization compatibility with previous * versions of this class introduces several oddities. Mainly: We @@ -468,6 +484,13 @@ public class ConcurrentHashMapV8 * time that we can guarantee to honor it.) We also declare an * unused "Segment" class that is instantiated in minimal form * only when serializing. + * + * This file is organized to make things a little easier to follow + * while reading than they might otherwise: First the main static + * declarations and utilities, then fields, then main public + * methods (with a few factorings of multiple public methods into + * internal ones), then sizing methods, trees, traversers, and + * bulk operations. */ /* ---------------- Constants -------------- */ @@ -510,10 +533,28 @@ public class ConcurrentHashMapV8 /** * The bin count threshold for using a tree rather than list for a - * bin. The value reflects the approximate break-even point for - * using tree-based operations. + * bin. Bins are converted to trees when adding an element to a + * bin with at least this many nodes. The value must be greater + * than 2, and should be at least 8 to mesh with assumptions in + * tree removal about conversion back to plain bins upon + * shrinkage. */ - private static final int TREE_THRESHOLD = 8; + static final int TREEIFY_THRESHOLD = 8; + + /** + * The bin count threshold for untreeifying a (split) bin during a + * resize operation. Should be less than TREEIFY_THRESHOLD, and at + * most 6 to mesh with shrinkage detection under removal. + */ + static final int UNTREEIFY_THRESHOLD = 6; + + /** + * The smallest table capacity for which bins may be treeified. + * (Otherwise the table is resized if too many nodes in a bin.) + * The value should be at least 4 * TREEIFY_THRESHOLD to avoid + * conflicts between resizing and treeification thresholds. + */ + static final int MIN_TREEIFY_CAPACITY = 64; /** * Minimum number of rebinnings per transfer step. Ranges are @@ -527,50 +568,178 @@ public class ConcurrentHashMapV8 /* * Encodings for Node hash fields. See above for explanation. */ - static final int MOVED = 0x80000000; // hash field for forwarding nodes + static final int MOVED = -1; // hash for forwarding nodes + static final int TREEBIN = -2; // hash for roots of trees + static final int RESERVED = -3; // hash for transient reservations static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash /** Number of CPUS, to place bounds on some sizings */ static final int NCPU = Runtime.getRuntime().availableProcessors(); - /* ---------------- Counters -------------- */ + /** For serialization compatibility. */ + private static final ObjectStreamField[] serialPersistentFields = { + new ObjectStreamField("segments", Segment[].class), + new ObjectStreamField("segmentMask", Integer.TYPE), + new ObjectStreamField("segmentShift", Integer.TYPE) + }; - // Adapted from LongAdder and Striped64. - // See their internal docs for explanation. + /* ---------------- Nodes -------------- */ - // A padded cell for distributing counts - static final class CounterCell { - volatile long p0, p1, p2, p3, p4, p5, p6; - volatile long value; - volatile long q0, q1, q2, q3, q4, q5, q6; - CounterCell(long x) { value = x; } + /** + * Key-value entry. This class is never exported out as a + * user-mutable Map.Entry (i.e., one supporting setValue; see + * MapEntry below), but can be used for read-only traversals used + * in bulk tasks. Subclasses of Node with a negative hash field + * are special, and contain null keys and values (but are never + * exported). Otherwise, keys and vals are never null. + */ + static class Node implements Map.Entry { + final int hash; + final K key; + volatile V val; + volatile Node next; + + Node(int hash, K key, V val, Node next) { + this.hash = hash; + this.key = key; + this.val = val; + this.next = next; + } + + public final K getKey() { return key; } + public final V getValue() { return val; } + public final int hashCode() { return key.hashCode() ^ val.hashCode(); } + public final String toString(){ return key + "=" + val; } + public final V setValue(V value) { + throw new UnsupportedOperationException(); + } + + public final boolean equals(Object o) { + Object k, v, u; Map.Entry e; + return ((o instanceof Map.Entry) && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + (k == key || k.equals(key)) && + (v == (u = val) || v.equals(u))); + } + + /** + * Virtualized support for map.get(); overridden in subclasses. + */ + Node find(int h, Object k) { + Node e = this; + if (k != null) { + do { + K ek; + if (e.hash == h && + ((ek = e.key) == k || (ek != null && k.equals(ek)))) + return e; + } while ((e = e.next) != null); + } + return null; + } + } + + /* ---------------- Static utilities -------------- */ + + /** + * Spreads (XORs) higher bits of hash to lower and also forces top + * bit to 0. Because the table uses power-of-two masking, sets of + * hashes that vary only in bits above the current mask will + * always collide. (Among known examples are sets of Float keys + * holding consecutive whole numbers in small tables.) So we + * apply a transform that spreads the impact of higher bits + * downward. There is a tradeoff between speed, utility, and + * quality of bit-spreading. Because many common sets of hashes + * are already reasonably distributed (so don't benefit from + * spreading), and because we use trees to handle large sets of + * collisions in bins, we just XOR some shifted bits in the + * cheapest possible way to reduce systematic lossage, as well as + * to incorporate impact of the highest bits that would otherwise + * never be used in index calculations because of table bounds. + */ + static final int spread(int h) { + return (h ^ (h >>> 16)) & HASH_BITS; } /** - * Holder for the thread-local hash code determining which - * CounterCell to use. The code is initialized via the - * counterHashCodeGenerator, but may be moved upon collisions. + * Returns a power of two table size for the given desired capacity. + * See Hackers Delight, sec 3.2 */ - static final class CounterHashCode { - int code; + private static final int tableSizeFor(int c) { + int n = c - 1; + n |= n >>> 1; + n |= n >>> 2; + n |= n >>> 4; + n |= n >>> 8; + n |= n >>> 16; + return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1; } /** - * Generates initial value for per-thread CounterHashCodes + * Returns x's Class if it is of the form "class C implements + * Comparable", else null. */ - static final AtomicInteger counterHashCodeGenerator = new AtomicInteger(); + static Class comparableClassFor(Object x) { + if (x instanceof Comparable) { + Class c; Type[] ts, as; Type t; ParameterizedType p; + if ((c = x.getClass()) == String.class) // bypass checks + return c; + if ((ts = c.getGenericInterfaces()) != null) { + for (int i = 0; i < ts.length; ++i) { + if (((t = ts[i]) instanceof ParameterizedType) && + ((p = (ParameterizedType)t).getRawType() == + Comparable.class) && + (as = p.getActualTypeArguments()) != null && + as.length == 1 && as[0] == c) // type arg is c + return c; + } + } + } + return null; + } /** - * Increment for counterHashCodeGenerator. See class ThreadLocal - * for explanation. + * Returns k.compareTo(x) if x matches kc (k's screened comparable + * class), else 0. */ - static final int SEED_INCREMENT = 0x61c88647; + @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable + static int compareComparables(Class kc, Object k, Object x) { + return (x == null || x.getClass() != kc ? 0 : + ((Comparable)k).compareTo(x)); + } - /** - * Per-thread counter hash codes. Shared across all instances. + /* ---------------- Table element access -------------- */ + + /* + * Volatile access methods are used for table elements as well as + * elements of in-progress next table while resizing. All uses of + * the tab arguments must be null checked by callers. All callers + * also paranoically precheck that tab's length is not zero (or an + * equivalent check), thus ensuring that any index argument taking + * the form of a hash value anded with (length - 1) is a valid + * index. Note that, to be correct wrt arbitrary concurrency + * errors by users, these checks must operate on local variables, + * which accounts for some odd-looking inline assignments below. + * Note that calls to setTabAt always occur within locked regions, + * and so in principle require only release ordering, not need + * full volatile semantics, but are currently coded as volatile + * writes to be conservative. */ - static final ThreadLocal threadCounterHashCode = - new ThreadLocal(); + + @SuppressWarnings("unchecked") + static final Node tabAt(Node[] tab, int i) { + return (Node)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE); + } + + static final boolean casTabAt(Node[] tab, int i, + Node c, Node v) { + return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v); + } + + static final void setTabAt(Node[] tab, int i, Node v) { + U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v); + } /* ---------------- Fields -------------- */ @@ -578,12 +747,12 @@ public class ConcurrentHashMapV8 * The array of bins. Lazily initialized upon first insertion. * Size is always a power of two. Accessed directly by iterators. */ - transient volatile Node[] table; + transient volatile Node[] table; /** * The next table to use; non-null only while resizing. */ - private transient volatile Node[] nextTable; + private transient volatile Node[] nextTable; /** * Base counter value, used mainly when there is no contention, @@ -613,9 +782,9 @@ public class ConcurrentHashMapV8 private transient volatile int transferOrigin; /** - * Spinlock (locked via CAS) used when resizing and/or creating Cells. + * Spinlock (locked via CAS) used when resizing and/or creating CounterCells. */ - private transient volatile int counterBusy; + private transient volatile int cellsBusy; /** * Table of counter cells. When non-null, size is a power of 2. @@ -627,1775 +796,6 @@ public class ConcurrentHashMapV8 private transient ValuesView values; private transient EntrySetView entrySet; - /** For serialization compatibility. Null unless serialized; see below */ - private Segment[] segments; - - /* ---------------- Table element access -------------- */ - - /* - * Volatile access methods are used for table elements as well as - * elements of in-progress next table while resizing. Uses are - * null checked by callers, and implicitly bounds-checked, relying - * on the invariants that tab arrays have non-zero size, and all - * indices are masked with (tab.length - 1) which is never - * negative and always less than length. Note that, to be correct - * wrt arbitrary concurrency errors by users, bounds checks must - * operate on local variables, which accounts for some odd-looking - * inline assignments below. - */ - - @SuppressWarnings("unchecked") static final Node tabAt - (Node[] tab, int i) { // used by Traverser - return (Node)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE); - } - - private static final boolean casTabAt - (Node[] tab, int i, Node c, Node v) { - return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v); - } - - private static final void setTabAt - (Node[] tab, int i, Node v) { - U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v); - } - - /* ---------------- Nodes -------------- */ - - /** - * Key-value entry. Note that this is never exported out as a - * user-visible Map.Entry (see MapEntry below). Nodes with a hash - * field of MOVED are special, and do not contain user keys or - * values. Otherwise, keys are never null, and null val fields - * indicate that a node is in the process of being deleted or - * created. For purposes of read-only access, a key may be read - * before a val, but can only be used after checking val to be - * non-null. - */ - static class Node { - final int hash; - final Object key; - volatile V val; - volatile Node next; - - Node(int hash, Object key, V val, Node next) { - this.hash = hash; - this.key = key; - this.val = val; - this.next = next; - } - } - - /* ---------------- TreeBins -------------- */ - - /** - * Nodes for use in TreeBins - */ - static final class TreeNode extends Node { - TreeNode parent; // red-black tree links - TreeNode left; - TreeNode right; - TreeNode prev; // needed to unlink next upon deletion - boolean red; - - TreeNode(int hash, Object key, V val, Node next, TreeNode parent) { - super(hash, key, val, next); - this.parent = parent; - } - } - - /** - * A specialized form of red-black tree for use in bins - * whose size exceeds a threshold. - * - * TreeBins use a special form of comparison for search and - * related operations (which is the main reason we cannot use - * existing collections such as TreeMaps). TreeBins contain - * Comparable elements, but may contain others, as well as - * elements that are Comparable but not necessarily Comparable - * for the same T, so we cannot invoke compareTo among them. To - * handle this, the tree is ordered primarily by hash value, then - * by getClass().getName() order, and then by Comparator order - * among elements of the same class. On lookup at a node, if - * elements are not comparable or compare as 0, both left and - * right children may need to be searched in the case of tied hash - * values. (This corresponds to the full list search that would be - * necessary if all elements were non-Comparable and had tied - * hashes.) The red-black balancing code is updated from - * pre-jdk-collections - * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java) - * based in turn on Cormen, Leiserson, and Rivest "Introduction to - * Algorithms" (CLR). - * - * TreeBins also maintain a separate locking discipline than - * regular bins. Because they are forwarded via special MOVED - * nodes at bin heads (which can never change once established), - * we cannot use those nodes as locks. Instead, TreeBin - * extends AbstractQueuedSynchronizer to support a simple form of - * read-write lock. For update operations and table validation, - * the exclusive form of lock behaves in the same way as bin-head - * locks. However, lookups use shared read-lock mechanics to allow - * multiple readers in the absence of writers. Additionally, - * these lookups do not ever block: While the lock is not - * available, they proceed along the slow traversal path (via - * next-pointers) until the lock becomes available or the list is - * exhausted, whichever comes first. (These cases are not fast, - * but maximize aggregate expected throughput.) The AQS mechanics - * for doing this are straightforward. The lock state is held as - * AQS getState(). Read counts are negative; the write count (1) - * is positive. There are no signalling preferences among readers - * and writers. Since we don't need to export full Lock API, we - * just override the minimal AQS methods and use them directly. - */ - static final class TreeBin extends AbstractQueuedSynchronizer { - private static final long serialVersionUID = 2249069246763182397L; - transient TreeNode root; // root of tree - transient TreeNode first; // head of next-pointer list - - /* AQS overrides */ - public final boolean isHeldExclusively() { return getState() > 0; } - public final boolean tryAcquire(int ignore) { - if (compareAndSetState(0, 1)) { - setExclusiveOwnerThread(Thread.currentThread()); - return true; - } - return false; - } - public final boolean tryRelease(int ignore) { - setExclusiveOwnerThread(null); - setState(0); - return true; - } - public final int tryAcquireShared(int ignore) { - for (int c;;) { - if ((c = getState()) > 0) - return -1; - if (compareAndSetState(c, c -1)) - return 1; - } - } - public final boolean tryReleaseShared(int ignore) { - int c; - do {} while (!compareAndSetState(c = getState(), c + 1)); - return c == -1; - } - - /** From CLR */ - private void rotateLeft(TreeNode p) { - if (p != null) { - TreeNode r = p.right, pp, rl; - if ((rl = p.right = r.left) != null) - rl.parent = p; - if ((pp = r.parent = p.parent) == null) - root = r; - else if (pp.left == p) - pp.left = r; - else - pp.right = r; - r.left = p; - p.parent = r; - } - } - - /** From CLR */ - private void rotateRight(TreeNode p) { - if (p != null) { - TreeNode l = p.left, pp, lr; - if ((lr = p.left = l.right) != null) - lr.parent = p; - if ((pp = l.parent = p.parent) == null) - root = l; - else if (pp.right == p) - pp.right = l; - else - pp.left = l; - l.right = p; - p.parent = l; - } - } - - /** - * Returns the TreeNode (or null if not found) for the given key - * starting at given root. - */ - @SuppressWarnings("unchecked") final TreeNode getTreeNode - (int h, Object k, TreeNode p) { - Class c = k.getClass(); - while (p != null) { - int dir, ph; Object pk; Class pc; - if ((ph = p.hash) == h) { - if ((pk = p.key) == k || k.equals(pk)) - return p; - if (c != (pc = pk.getClass()) || - !(k instanceof Comparable) || - (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) { - if ((dir = (c == pc) ? 0 : - c.getName().compareTo(pc.getName())) == 0) { - TreeNode r = null, pl, pr; // check both sides - if ((pr = p.right) != null && h >= pr.hash && - (r = getTreeNode(h, k, pr)) != null) - return r; - else if ((pl = p.left) != null && h <= pl.hash) - dir = -1; - else // nothing there - return null; - } - } - } - else - dir = (h < ph) ? -1 : 1; - p = (dir > 0) ? p.right : p.left; - } - return null; - } - - /** - * Wrapper for getTreeNode used by CHM.get. Tries to obtain - * read-lock to call getTreeNode, but during failure to get - * lock, searches along next links. - */ - final V getValue(int h, Object k) { - Node r = null; - int c = getState(); // Must read lock state first - for (Node e = first; e != null; e = e.next) { - if (c <= 0 && compareAndSetState(c, c - 1)) { - try { - r = getTreeNode(h, k, root); - } finally { - releaseShared(0); - } - break; - } - else if (e.hash == h && k.equals(e.key)) { - r = e; - break; - } - else - c = getState(); - } - return r == null ? null : r.val; - } - - /** - * Finds or adds a node. - * @return null if added - */ - @SuppressWarnings("unchecked") final TreeNode putTreeNode - (int h, Object k, V v) { - Class c = k.getClass(); - TreeNode pp = root, p = null; - int dir = 0; - while (pp != null) { // find existing node or leaf to insert at - int ph; Object pk; Class pc; - p = pp; - if ((ph = p.hash) == h) { - if ((pk = p.key) == k || k.equals(pk)) - return p; - if (c != (pc = pk.getClass()) || - !(k instanceof Comparable) || - (dir = ((Comparable)k).compareTo((Comparable)pk)) == 0) { - TreeNode s = null, r = null, pr; - if ((dir = (c == pc) ? 0 : - c.getName().compareTo(pc.getName())) == 0) { - if ((pr = p.right) != null && h >= pr.hash && - (r = getTreeNode(h, k, pr)) != null) - return r; - else // continue left - dir = -1; - } - else if ((pr = p.right) != null && h >= pr.hash) - s = pr; - if (s != null && (r = getTreeNode(h, k, s)) != null) - return r; - } - } - else - dir = (h < ph) ? -1 : 1; - pp = (dir > 0) ? p.right : p.left; - } - - TreeNode f = first; - TreeNode x = first = new TreeNode(h, k, v, f, p); - if (p == null) - root = x; - else { // attach and rebalance; adapted from CLR - TreeNode xp, xpp; - if (f != null) - f.prev = x; - if (dir <= 0) - p.left = x; - else - p.right = x; - x.red = true; - while (x != null && (xp = x.parent) != null && xp.red && - (xpp = xp.parent) != null) { - TreeNode xppl = xpp.left; - if (xp == xppl) { - TreeNode y = xpp.right; - if (y != null && y.red) { - y.red = false; - xp.red = false; - xpp.red = true; - x = xpp; - } - else { - if (x == xp.right) { - rotateLeft(x = xp); - xpp = (xp = x.parent) == null ? null : xp.parent; - } - if (xp != null) { - xp.red = false; - if (xpp != null) { - xpp.red = true; - rotateRight(xpp); - } - } - } - } - else { - TreeNode y = xppl; - if (y != null && y.red) { - y.red = false; - xp.red = false; - xpp.red = true; - x = xpp; - } - else { - if (x == xp.left) { - rotateRight(x = xp); - xpp = (xp = x.parent) == null ? null : xp.parent; - } - if (xp != null) { - xp.red = false; - if (xpp != null) { - xpp.red = true; - rotateLeft(xpp); - } - } - } - } - } - TreeNode r = root; - if (r != null && r.red) - r.red = false; - } - return null; - } - - /** - * Removes the given node, that must be present before this - * call. This is messier than typical red-black deletion code - * because we cannot swap the contents of an interior node - * with a leaf successor that is pinned by "next" pointers - * that are accessible independently of lock. So instead we - * swap the tree linkages. - */ - final void deleteTreeNode(TreeNode p) { - TreeNode next = (TreeNode)p.next; // unlink traversal pointers - TreeNode pred = p.prev; - if (pred == null) - first = next; - else - pred.next = next; - if (next != null) - next.prev = pred; - TreeNode replacement; - TreeNode pl = p.left; - TreeNode pr = p.right; - if (pl != null && pr != null) { - TreeNode s = pr, sl; - while ((sl = s.left) != null) // find successor - s = sl; - boolean c = s.red; s.red = p.red; p.red = c; // swap colors - TreeNode sr = s.right; - TreeNode pp = p.parent; - if (s == pr) { // p was s's direct parent - p.parent = s; - s.right = p; - } - else { - TreeNode sp = s.parent; - if ((p.parent = sp) != null) { - if (s == sp.left) - sp.left = p; - else - sp.right = p; - } - if ((s.right = pr) != null) - pr.parent = s; - } - p.left = null; - if ((p.right = sr) != null) - sr.parent = p; - if ((s.left = pl) != null) - pl.parent = s; - if ((s.parent = pp) == null) - root = s; - else if (p == pp.left) - pp.left = s; - else - pp.right = s; - replacement = sr; - } - else - replacement = (pl != null) ? pl : pr; - TreeNode pp = p.parent; - if (replacement == null) { - if (pp == null) { - root = null; - return; - } - replacement = p; - } - else { - replacement.parent = pp; - if (pp == null) - root = replacement; - else if (p == pp.left) - pp.left = replacement; - else - pp.right = replacement; - p.left = p.right = p.parent = null; - } - if (!p.red) { // rebalance, from CLR - TreeNode x = replacement; - while (x != null) { - TreeNode xp, xpl; - if (x.red || (xp = x.parent) == null) { - x.red = false; - break; - } - if (x == (xpl = xp.left)) { - TreeNode sib = xp.right; - if (sib != null && sib.red) { - sib.red = false; - xp.red = true; - rotateLeft(xp); - sib = (xp = x.parent) == null ? null : xp.right; - } - if (sib == null) - x = xp; - else { - TreeNode sl = sib.left, sr = sib.right; - if ((sr == null || !sr.red) && - (sl == null || !sl.red)) { - sib.red = true; - x = xp; - } - else { - if (sr == null || !sr.red) { - if (sl != null) - sl.red = false; - sib.red = true; - rotateRight(sib); - sib = (xp = x.parent) == null ? - null : xp.right; - } - if (sib != null) { - sib.red = (xp == null) ? false : xp.red; - if ((sr = sib.right) != null) - sr.red = false; - } - if (xp != null) { - xp.red = false; - rotateLeft(xp); - } - x = root; - } - } - } - else { // symmetric - TreeNode sib = xpl; - if (sib != null && sib.red) { - sib.red = false; - xp.red = true; - rotateRight(xp); - sib = (xp = x.parent) == null ? null : xp.left; - } - if (sib == null) - x = xp; - else { - TreeNode sl = sib.left, sr = sib.right; - if ((sl == null || !sl.red) && - (sr == null || !sr.red)) { - sib.red = true; - x = xp; - } - else { - if (sl == null || !sl.red) { - if (sr != null) - sr.red = false; - sib.red = true; - rotateLeft(sib); - sib = (xp = x.parent) == null ? - null : xp.left; - } - if (sib != null) { - sib.red = (xp == null) ? false : xp.red; - if ((sl = sib.left) != null) - sl.red = false; - } - if (xp != null) { - xp.red = false; - rotateRight(xp); - } - x = root; - } - } - } - } - } - if (p == replacement && (pp = p.parent) != null) { - if (p == pp.left) // detach pointers - pp.left = null; - else if (p == pp.right) - pp.right = null; - p.parent = null; - } - } - } - - /* ---------------- Collision reduction methods -------------- */ - - /** - * Spreads higher bits to lower, and also forces top bit to 0. - * Because the table uses power-of-two masking, sets of hashes - * that vary only in bits above the current mask will always - * collide. (Among known examples are sets of Float keys holding - * consecutive whole numbers in small tables.) To counter this, - * we apply a transform that spreads the impact of higher bits - * downward. There is a tradeoff between speed, utility, and - * quality of bit-spreading. Because many common sets of hashes - * are already reasonably distributed across bits (so don't benefit - * from spreading), and because we use trees to handle large sets - * of collisions in bins, we don't need excessively high quality. - */ - private static final int spread(int h) { - h ^= (h >>> 18) ^ (h >>> 12); - return (h ^ (h >>> 10)) & HASH_BITS; - } - - /** - * Replaces a list bin with a tree bin if key is comparable. Call - * only when locked. - */ - private final void replaceWithTreeBin(Node[] tab, int index, Object key) { - if (key instanceof Comparable) { - TreeBin t = new TreeBin(); - for (Node e = tabAt(tab, index); e != null; e = e.next) - t.putTreeNode(e.hash, e.key, e.val); - setTabAt(tab, index, new Node(MOVED, t, null, null)); - } - } - - /* ---------------- Internal access and update methods -------------- */ - - /** Implementation for get and containsKey */ - @SuppressWarnings("unchecked") private final V internalGet(Object k) { - int h = spread(k.hashCode()); - retry: for (Node[] tab = table; tab != null;) { - Node e; Object ek; V ev; int eh; // locals to read fields once - for (e = tabAt(tab, (tab.length - 1) & h); e != null; e = e.next) { - if ((eh = e.hash) < 0) { - if ((ek = e.key) instanceof TreeBin) // search TreeBin - return ((TreeBin)ek).getValue(h, k); - else { // restart with new table - tab = (Node[])ek; - continue retry; - } - } - else if (eh == h && (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) - return ev; - } - break; - } - return null; - } - - /** - * Implementation for the four public remove/replace methods: - * Replaces node value with v, conditional upon match of cv if - * non-null. If resulting value is null, delete. - */ - @SuppressWarnings("unchecked") private final V internalReplace - (Object k, V v, Object cv) { - int h = spread(k.hashCode()); - V oldVal = null; - for (Node[] tab = table;;) { - Node f; int i, fh; Object fk; - if (tab == null || - (f = tabAt(tab, i = (tab.length - 1) & h)) == null) - break; - else if ((fh = f.hash) < 0) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean validated = false; - boolean deleted = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - validated = true; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p != null) { - V pv = p.val; - if (cv == null || cv == pv || cv.equals(pv)) { - oldVal = pv; - if ((p.val = v) == null) { - deleted = true; - t.deleteTreeNode(p); - } - } - } - } - } finally { - t.release(0); - } - if (validated) { - if (deleted) - addCount(-1L, -1); - break; - } - } - else - tab = (Node[])fk; - } - else if (fh != h && f.next == null) // precheck - break; // rules out possible existence - else { - boolean validated = false; - boolean deleted = false; - synchronized (f) { - if (tabAt(tab, i) == f) { - validated = true; - for (Node e = f, pred = null;;) { - Object ek; V ev; - if (e.hash == h && - ((ev = e.val) != null) && - ((ek = e.key) == k || k.equals(ek))) { - if (cv == null || cv == ev || cv.equals(ev)) { - oldVal = ev; - if ((e.val = v) == null) { - deleted = true; - Node en = e.next; - if (pred != null) - pred.next = en; - else - setTabAt(tab, i, en); - } - } - break; - } - pred = e; - if ((e = e.next) == null) - break; - } - } - } - if (validated) { - if (deleted) - addCount(-1L, -1); - break; - } - } - } - return oldVal; - } - - /* - * Internal versions of insertion methods - * All have the same basic structure as the first (internalPut): - * 1. If table uninitialized, create - * 2. If bin empty, try to CAS new node - * 3. If bin stale, use new table - * 4. if bin converted to TreeBin, validate and relay to TreeBin methods - * 5. Lock and validate; if valid, scan and add or update - * - * The putAll method differs mainly in attempting to pre-allocate - * enough table space, and also more lazily performs count updates - * and checks. - * - * Most of the function-accepting methods can't be factored nicely - * because they require different functional forms, so instead - * sprawl out similar mechanics. - */ - - /** Implementation for put and putIfAbsent */ - @SuppressWarnings("unchecked") private final V internalPut - (K k, V v, boolean onlyIfAbsent) { - if (k == null || v == null) throw new NullPointerException(); - int h = spread(k.hashCode()); - int len = 0; - for (Node[] tab = table;;) { - int i, fh; Node f; Object fk; V fv; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { - if (casTabAt(tab, i, null, new Node(h, k, v, null))) - break; // no lock when adding to empty bin - } - else if ((fh = f.hash) < 0) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - V oldVal = null; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - len = 2; - TreeNode p = t.putTreeNode(h, k, v); - if (p != null) { - oldVal = p.val; - if (!onlyIfAbsent) - p.val = v; - } - } - } finally { - t.release(0); - } - if (len != 0) { - if (oldVal != null) - return oldVal; - break; - } - } - else - tab = (Node[])fk; - } - else if (onlyIfAbsent && fh == h && (fv = f.val) != null && - ((fk = f.key) == k || k.equals(fk))) // peek while nearby - return fv; - else { - V oldVal = null; - synchronized (f) { - if (tabAt(tab, i) == f) { - len = 1; - for (Node e = f;; ++len) { - Object ek; V ev; - if (e.hash == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - oldVal = ev; - if (!onlyIfAbsent) - e.val = v; - break; - } - Node last = e; - if ((e = e.next) == null) { - last.next = new Node(h, k, v, null); - if (len >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } - if (len != 0) { - if (oldVal != null) - return oldVal; - break; - } - } - } - addCount(1L, len); - return null; - } - - /** Implementation for computeIfAbsent */ - @SuppressWarnings("unchecked") private final V internalComputeIfAbsent - (K k, Fun mf) { - if (k == null || mf == null) - throw new NullPointerException(); - int h = spread(k.hashCode()); - V val = null; - int len = 0; - for (Node[] tab = table;;) { - Node f; int i; Object fk; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { - Node node = new Node(h, k, null, null); - synchronized (node) { - if (casTabAt(tab, i, null, node)) { - len = 1; - try { - if ((val = mf.apply(k)) != null) - node.val = val; - } finally { - if (val == null) - setTabAt(tab, i, null); - } - } - } - if (len != 0) - break; - } - else if (f.hash < 0) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean added = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - len = 1; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p != null) - val = p.val; - else if ((val = mf.apply(k)) != null) { - added = true; - len = 2; - t.putTreeNode(h, k, val); - } - } - } finally { - t.release(0); - } - if (len != 0) { - if (!added) - return val; - break; - } - } - else - tab = (Node[])fk; - } - else { - for (Node e = f; e != null; e = e.next) { // prescan - Object ek; V ev; - if (e.hash == h && (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) - return ev; - } - boolean added = false; - synchronized (f) { - if (tabAt(tab, i) == f) { - len = 1; - for (Node e = f;; ++len) { - Object ek; V ev; - if (e.hash == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - val = ev; - break; - } - Node last = e; - if ((e = e.next) == null) { - if ((val = mf.apply(k)) != null) { - added = true; - last.next = new Node(h, k, val, null); - if (len >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - } - break; - } - } - } - } - if (len != 0) { - if (!added) - return val; - break; - } - } - } - if (val != null) - addCount(1L, len); - return val; - } - - /** Implementation for compute */ - @SuppressWarnings("unchecked") private final V internalCompute - (K k, boolean onlyIfPresent, - BiFun mf) { - if (k == null || mf == null) - throw new NullPointerException(); - int h = spread(k.hashCode()); - V val = null; - int delta = 0; - int len = 0; - for (Node[] tab = table;;) { - Node f; int i, fh; Object fk; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { - if (onlyIfPresent) - break; - Node node = new Node(h, k, null, null); - synchronized (node) { - if (casTabAt(tab, i, null, node)) { - try { - len = 1; - if ((val = mf.apply(k, null)) != null) { - node.val = val; - delta = 1; - } - } finally { - if (delta == 0) - setTabAt(tab, i, null); - } - } - } - if (len != 0) - break; - } - else if ((fh = f.hash) < 0) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - len = 1; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p == null && onlyIfPresent) - break; - V pv = (p == null) ? null : p.val; - if ((val = mf.apply(k, pv)) != null) { - if (p != null) - p.val = val; - else { - len = 2; - delta = 1; - t.putTreeNode(h, k, val); - } - } - else if (p != null) { - delta = -1; - t.deleteTreeNode(p); - } - } - } finally { - t.release(0); - } - if (len != 0) - break; - } - else - tab = (Node[])fk; - } - else { - synchronized (f) { - if (tabAt(tab, i) == f) { - len = 1; - for (Node e = f, pred = null;; ++len) { - Object ek; V ev; - if (e.hash == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - val = mf.apply(k, ev); - if (val != null) - e.val = val; - else { - delta = -1; - Node en = e.next; - if (pred != null) - pred.next = en; - else - setTabAt(tab, i, en); - } - break; - } - pred = e; - if ((e = e.next) == null) { - if (!onlyIfPresent && - (val = mf.apply(k, null)) != null) { - pred.next = new Node(h, k, val, null); - delta = 1; - if (len >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - } - break; - } - } - } - } - if (len != 0) - break; - } - } - if (delta != 0) - addCount((long)delta, len); - return val; - } - - /** Implementation for merge */ - @SuppressWarnings("unchecked") private final V internalMerge - (K k, V v, BiFun mf) { - if (k == null || v == null || mf == null) - throw new NullPointerException(); - int h = spread(k.hashCode()); - V val = null; - int delta = 0; - int len = 0; - for (Node[] tab = table;;) { - int i; Node f; Object fk; V fv; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null) { - if (casTabAt(tab, i, null, new Node(h, k, v, null))) { - delta = 1; - val = v; - break; - } - } - else if (f.hash < 0) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - len = 1; - TreeNode p = t.getTreeNode(h, k, t.root); - val = (p == null) ? v : mf.apply(p.val, v); - if (val != null) { - if (p != null) - p.val = val; - else { - len = 2; - delta = 1; - t.putTreeNode(h, k, val); - } - } - else if (p != null) { - delta = -1; - t.deleteTreeNode(p); - } - } - } finally { - t.release(0); - } - if (len != 0) - break; - } - else - tab = (Node[])fk; - } - else { - synchronized (f) { - if (tabAt(tab, i) == f) { - len = 1; - for (Node e = f, pred = null;; ++len) { - Object ek; V ev; - if (e.hash == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - val = mf.apply(ev, v); - if (val != null) - e.val = val; - else { - delta = -1; - Node en = e.next; - if (pred != null) - pred.next = en; - else - setTabAt(tab, i, en); - } - break; - } - pred = e; - if ((e = e.next) == null) { - val = v; - pred.next = new Node(h, k, val, null); - delta = 1; - if (len >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } - if (len != 0) - break; - } - } - if (delta != 0) - addCount((long)delta, len); - return val; - } - - /** Implementation for putAll */ - @SuppressWarnings("unchecked") private final void internalPutAll - (Map m) { - tryPresize(m.size()); - long delta = 0L; // number of uncommitted additions - boolean npe = false; // to throw exception on exit for nulls - try { // to clean up counts on other exceptions - for (Map.Entry entry : m.entrySet()) { - Object k; V v; - if (entry == null || (k = entry.getKey()) == null || - (v = entry.getValue()) == null) { - npe = true; - break; - } - int h = spread(k.hashCode()); - for (Node[] tab = table;;) { - int i; Node f; int fh; Object fk; - if (tab == null) - tab = initTable(); - else if ((f = tabAt(tab, i = (tab.length - 1) & h)) == null){ - if (casTabAt(tab, i, null, new Node(h, k, v, null))) { - ++delta; - break; - } - } - else if ((fh = f.hash) < 0) { - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - boolean validated = false; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - validated = true; - TreeNode p = t.getTreeNode(h, k, t.root); - if (p != null) - p.val = v; - else { - t.putTreeNode(h, k, v); - ++delta; - } - } - } finally { - t.release(0); - } - if (validated) - break; - } - else - tab = (Node[])fk; - } - else { - int len = 0; - synchronized (f) { - if (tabAt(tab, i) == f) { - len = 1; - for (Node e = f;; ++len) { - Object ek; V ev; - if (e.hash == h && - (ev = e.val) != null && - ((ek = e.key) == k || k.equals(ek))) { - e.val = v; - break; - } - Node last = e; - if ((e = e.next) == null) { - ++delta; - last.next = new Node(h, k, v, null); - if (len >= TREE_THRESHOLD) - replaceWithTreeBin(tab, i, k); - break; - } - } - } - } - if (len != 0) { - if (len > 1) { - addCount(delta, len); - delta = 0L; - } - break; - } - } - } - } - } finally { - if (delta != 0L) - addCount(delta, 2); - } - if (npe) - throw new NullPointerException(); - } - - /** - * Implementation for clear. Steps through each bin, removing all - * nodes. - */ - @SuppressWarnings("unchecked") private final void internalClear() { - long delta = 0L; // negative number of deletions - int i = 0; - Node[] tab = table; - while (tab != null && i < tab.length) { - Node f = tabAt(tab, i); - if (f == null) - ++i; - else if (f.hash < 0) { - Object fk; - if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - for (Node p = t.first; p != null; p = p.next) { - if (p.val != null) { // (currently always true) - p.val = null; - --delta; - } - } - t.first = null; - t.root = null; - ++i; - } - } finally { - t.release(0); - } - } - else - tab = (Node[])fk; - } - else { - synchronized (f) { - if (tabAt(tab, i) == f) { - for (Node e = f; e != null; e = e.next) { - if (e.val != null) { // (currently always true) - e.val = null; - --delta; - } - } - setTabAt(tab, i, null); - ++i; - } - } - } - } - if (delta != 0L) - addCount(delta, -1); - } - - /* ---------------- Table Initialization and Resizing -------------- */ - - /** - * Returns a power of two table size for the given desired capacity. - * See Hackers Delight, sec 3.2 - */ - private static final int tableSizeFor(int c) { - int n = c - 1; - n |= n >>> 1; - n |= n >>> 2; - n |= n >>> 4; - n |= n >>> 8; - n |= n >>> 16; - return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1; - } - - /** - * Initializes table, using the size recorded in sizeCtl. - */ - @SuppressWarnings("unchecked") private final Node[] initTable() { - Node[] tab; int sc; - while ((tab = table) == null) { - if ((sc = sizeCtl) < 0) - Thread.yield(); // lost initialization race; just spin - else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { - try { - if ((tab = table) == null) { - int n = (sc > 0) ? sc : DEFAULT_CAPACITY; - @SuppressWarnings("rawtypes") Node[] tb = new Node[n]; - table = tab = (Node[])tb; - sc = n - (n >>> 2); - } - } finally { - sizeCtl = sc; - } - break; - } - } - return tab; - } - - /** - * Adds to count, and if table is too small and not already - * resizing, initiates transfer. If already resizing, helps - * perform transfer if work is available. Rechecks occupancy - * after a transfer to see if another resize is already needed - * because resizings are lagging additions. - * - * @param x the count to add - * @param check if <0, don't check resize, if <= 1 only check if uncontended - */ - private final void addCount(long x, int check) { - CounterCell[] as; long b, s; - if ((as = counterCells) != null || - !U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) { - CounterHashCode hc; CounterCell a; long v; int m; - boolean uncontended = true; - if ((hc = threadCounterHashCode.get()) == null || - as == null || (m = as.length - 1) < 0 || - (a = as[m & hc.code]) == null || - !(uncontended = - U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) { - fullAddCount(x, hc, uncontended); - return; - } - if (check <= 1) - return; - s = sumCount(); - } - if (check >= 0) { - Node[] tab, nt; int sc; - while (s >= (long)(sc = sizeCtl) && (tab = table) != null && - tab.length < MAXIMUM_CAPACITY) { - if (sc < 0) { - if (sc == -1 || transferIndex <= transferOrigin || - (nt = nextTable) == null) - break; - if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) - transfer(tab, nt); - } - else if (U.compareAndSwapInt(this, SIZECTL, sc, -2)) - transfer(tab, null); - s = sumCount(); - } - } - } - - /** - * Tries to presize table to accommodate the given number of elements. - * - * @param size number of elements (doesn't need to be perfectly accurate) - */ - @SuppressWarnings("unchecked") private final void tryPresize(int size) { - int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY : - tableSizeFor(size + (size >>> 1) + 1); - int sc; - while ((sc = sizeCtl) >= 0) { - Node[] tab = table; int n; - if (tab == null || (n = tab.length) == 0) { - n = (sc > c) ? sc : c; - if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { - try { - if (table == tab) { - @SuppressWarnings("rawtypes") Node[] tb = new Node[n]; - table = (Node[])tb; - sc = n - (n >>> 2); - } - } finally { - sizeCtl = sc; - } - } - } - else if (c <= sc || n >= MAXIMUM_CAPACITY) - break; - else if (tab == table && - U.compareAndSwapInt(this, SIZECTL, sc, -2)) - transfer(tab, null); - } - } - - /** - * Moves and/or copies the nodes in each bin to new table. See - * above for explanation. - */ - @SuppressWarnings("unchecked") private final void transfer - (Node[] tab, Node[] nextTab) { - int n = tab.length, stride; - if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE) - stride = MIN_TRANSFER_STRIDE; // subdivide range - if (nextTab == null) { // initiating - try { - @SuppressWarnings("rawtypes") Node[] tb = new Node[n << 1]; - nextTab = (Node[])tb; - } catch (Throwable ex) { // try to cope with OOME - sizeCtl = Integer.MAX_VALUE; - return; - } - nextTable = nextTab; - transferOrigin = n; - transferIndex = n; - Node rev = new Node(MOVED, tab, null, null); - for (int k = n; k > 0;) { // progressively reveal ready slots - int nextk = (k > stride) ? k - stride : 0; - for (int m = nextk; m < k; ++m) - nextTab[m] = rev; - for (int m = n + nextk; m < n + k; ++m) - nextTab[m] = rev; - U.putOrderedInt(this, TRANSFERORIGIN, k = nextk); - } - } - int nextn = nextTab.length; - Node fwd = new Node(MOVED, nextTab, null, null); - boolean advance = true; - for (int i = 0, bound = 0;;) { - int nextIndex, nextBound; Node f; Object fk; - while (advance) { - if (--i >= bound) - advance = false; - else if ((nextIndex = transferIndex) <= transferOrigin) { - i = -1; - advance = false; - } - else if (U.compareAndSwapInt - (this, TRANSFERINDEX, nextIndex, - nextBound = (nextIndex > stride ? - nextIndex - stride : 0))) { - bound = nextBound; - i = nextIndex - 1; - advance = false; - } - } - if (i < 0 || i >= n || i + n >= nextn) { - for (int sc;;) { - if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) { - if (sc == -1) { - nextTable = null; - table = nextTab; - sizeCtl = (n << 1) - (n >>> 1); - } - return; - } - } - } - else if ((f = tabAt(tab, i)) == null) { - if (casTabAt(tab, i, null, fwd)) { - setTabAt(nextTab, i, null); - setTabAt(nextTab, i + n, null); - advance = true; - } - } - else if (f.hash >= 0) { - synchronized (f) { - if (tabAt(tab, i) == f) { - int runBit = f.hash & n; - Node lastRun = f, lo = null, hi = null; - for (Node p = f.next; p != null; p = p.next) { - int b = p.hash & n; - if (b != runBit) { - runBit = b; - lastRun = p; - } - } - if (runBit == 0) - lo = lastRun; - else - hi = lastRun; - for (Node p = f; p != lastRun; p = p.next) { - int ph = p.hash; - Object pk = p.key; V pv = p.val; - if ((ph & n) == 0) - lo = new Node(ph, pk, pv, lo); - else - hi = new Node(ph, pk, pv, hi); - } - setTabAt(nextTab, i, lo); - setTabAt(nextTab, i + n, hi); - setTabAt(tab, i, fwd); - advance = true; - } - } - } - else if ((fk = f.key) instanceof TreeBin) { - TreeBin t = (TreeBin)fk; - t.acquire(0); - try { - if (tabAt(tab, i) == f) { - TreeBin lt = new TreeBin(); - TreeBin ht = new TreeBin(); - int lc = 0, hc = 0; - for (Node e = t.first; e != null; e = e.next) { - int h = e.hash; - Object k = e.key; V v = e.val; - if ((h & n) == 0) { - ++lc; - lt.putTreeNode(h, k, v); - } - else { - ++hc; - ht.putTreeNode(h, k, v); - } - } - Node ln, hn; // throw away trees if too small - if (lc < TREE_THRESHOLD) { - ln = null; - for (Node p = lt.first; p != null; p = p.next) - ln = new Node(p.hash, p.key, p.val, ln); - } - else - ln = new Node(MOVED, lt, null, null); - setTabAt(nextTab, i, ln); - if (hc < TREE_THRESHOLD) { - hn = null; - for (Node p = ht.first; p != null; p = p.next) - hn = new Node(p.hash, p.key, p.val, hn); - } - else - hn = new Node(MOVED, ht, null, null); - setTabAt(nextTab, i + n, hn); - setTabAt(tab, i, fwd); - advance = true; - } - } finally { - t.release(0); - } - } - else - advance = true; // already processed - } - } - - /* ---------------- Counter support -------------- */ - - final long sumCount() { - CounterCell[] as = counterCells; CounterCell a; - long sum = baseCount; - if (as != null) { - for (int i = 0; i < as.length; ++i) { - if ((a = as[i]) != null) - sum += a.value; - } - } - return sum; - } - - // See LongAdder version for explanation - private final void fullAddCount(long x, CounterHashCode hc, - boolean wasUncontended) { - int h; - if (hc == null) { - hc = new CounterHashCode(); - int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT); - h = hc.code = (s == 0) ? 1 : s; // Avoid zero - threadCounterHashCode.set(hc); - } - else - h = hc.code; - boolean collide = false; // True if last slot nonempty - for (;;) { - CounterCell[] as; CounterCell a; int n; long v; - if ((as = counterCells) != null && (n = as.length) > 0) { - if ((a = as[(n - 1) & h]) == null) { - if (counterBusy == 0) { // Try to attach new Cell - CounterCell r = new CounterCell(x); // Optimistic create - if (counterBusy == 0 && - U.compareAndSwapInt(this, COUNTERBUSY, 0, 1)) { - boolean created = false; - try { // Recheck under lock - CounterCell[] rs; int m, j; - if ((rs = counterCells) != null && - (m = rs.length) > 0 && - rs[j = (m - 1) & h] == null) { - rs[j] = r; - created = true; - } - } finally { - counterBusy = 0; - } - if (created) - break; - continue; // Slot is now non-empty - } - } - collide = false; - } - else if (!wasUncontended) // CAS already known to fail - wasUncontended = true; // Continue after rehash - else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x)) - break; - else if (counterCells != as || n >= NCPU) - collide = false; // At max size or stale - else if (!collide) - collide = true; - else if (counterBusy == 0 && - U.compareAndSwapInt(this, COUNTERBUSY, 0, 1)) { - try { - if (counterCells == as) {// Expand table unless stale - CounterCell[] rs = new CounterCell[n << 1]; - for (int i = 0; i < n; ++i) - rs[i] = as[i]; - counterCells = rs; - } - } finally { - counterBusy = 0; - } - collide = false; - continue; // Retry with expanded table - } - h ^= h << 13; // Rehash - h ^= h >>> 17; - h ^= h << 5; - } - else if (counterBusy == 0 && counterCells == as && - U.compareAndSwapInt(this, COUNTERBUSY, 0, 1)) { - boolean init = false; - try { // Initialize table - if (counterCells == as) { - CounterCell[] rs = new CounterCell[2]; - rs[h & 1] = new CounterCell(x); - counterCells = rs; - init = true; - } - } finally { - counterBusy = 0; - } - if (init) - break; - } - else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x)) - break; // Fall back on using base - } - hc.code = h; // Record index for next time - } - - /* ----------------Table Traversal -------------- */ - - /** - * Encapsulates traversal for methods such as containsValue; also - * serves as a base class for other iterators and bulk tasks. - * - * At each step, the iterator snapshots the key ("nextKey") and - * value ("nextVal") of a valid node (i.e., one that, at point of - * snapshot, has a non-null user value). Because val fields can - * change (including to null, indicating deletion), field nextVal - * might not be accurate at point of use, but still maintains the - * weak consistency property of holding a value that was once - * valid. To support iterator.remove, the nextKey field is not - * updated (nulled out) when the iterator cannot advance. - * - * Internal traversals directly access these fields, as in: - * {@code while (it.advance() != null) { process(it.nextKey); }} - * - * Exported iterators must track whether the iterator has advanced - * (in hasNext vs next) (by setting/checking/nulling field - * nextVal), and then extract key, value, or key-value pairs as - * return values of next(). - * - * The iterator visits once each still-valid node that was - * reachable upon iterator construction. It might miss some that - * were added to a bin after the bin was visited, which is OK wrt - * consistency guarantees. Maintaining this property in the face - * of possible ongoing resizes requires a fair amount of - * bookkeeping state that is difficult to optimize away amidst - * volatile accesses. Even so, traversal maintains reasonable - * throughput. - * - * Normally, iteration proceeds bin-by-bin traversing lists. - * However, if the table has been resized, then all future steps - * must traverse both the bin at the current index as well as at - * (index + baseSize); and so on for further resizings. To - * paranoically cope with potential sharing by users of iterators - * across threads, iteration terminates if a bounds checks fails - * for a table read. - * - * This class extends CountedCompleter to streamline parallel - * iteration in bulk operations. This adds only a few fields of - * space overhead, which is small enough in cases where it is not - * needed to not worry about it. Because CountedCompleter is - * Serializable, but iterators need not be, we need to add warning - * suppressions. - */ - @SuppressWarnings("serial") static class Traverser - extends CountedCompleter { - final ConcurrentHashMapV8 map; - Node next; // the next entry to use - Object nextKey; // cached key field of next - V nextVal; // cached val field of next - Node[] tab; // current table; updated if resized - int index; // index of bin to use next - int baseIndex; // current index of initial table - int baseLimit; // index bound for initial table - int baseSize; // initial table size - int batch; // split control - - /** Creates iterator for all entries in the table. */ - Traverser(ConcurrentHashMapV8 map) { - this.map = map; - } - - /** Creates iterator for split() methods and task constructors */ - Traverser(ConcurrentHashMapV8 map, Traverser it, int batch) { - super(it); - this.batch = batch; - if ((this.map = map) != null && it != null) { // split parent - Node[] t; - if ((t = it.tab) == null && - (t = it.tab = map.table) != null) - it.baseLimit = it.baseSize = t.length; - this.tab = t; - this.baseSize = it.baseSize; - int hi = this.baseLimit = it.baseLimit; - it.baseLimit = this.index = this.baseIndex = - (hi + it.baseIndex + 1) >>> 1; - } - } - - /** - * Advances next; returns nextVal or null if terminated. - * See above for explanation. - */ - @SuppressWarnings("unchecked") final V advance() { - Node e = next; - V ev = null; - outer: do { - if (e != null) // advance past used/skipped node - e = e.next; - while (e == null) { // get to next non-null bin - ConcurrentHashMapV8 m; - Node[] t; int b, i, n; Object ek; // must use locals - if ((t = tab) != null) - n = t.length; - else if ((m = map) != null && (t = tab = m.table) != null) - n = baseLimit = baseSize = t.length; - else - break outer; - if ((b = baseIndex) >= baseLimit || - (i = index) < 0 || i >= n) - break outer; - if ((e = tabAt(t, i)) != null && e.hash < 0) { - if ((ek = e.key) instanceof TreeBin) - e = ((TreeBin)ek).first; - else { - tab = (Node[])ek; - continue; // restarts due to null val - } - } // visit upper slots if present - index = (i += baseSize) < n ? i : (baseIndex = b + 1); - } - nextKey = e.key; - } while ((ev = e.val) == null); // skip deleted or special nodes - next = e; - return nextVal = ev; - } - - public final void remove() { - Object k = nextKey; - if (k == null && (advance() == null || (k = nextKey) == null)) - throw new IllegalStateException(); - map.internalReplace(k, null, null); - } - - public final boolean hasNext() { - return nextVal != null || advance() != null; - } - - public final boolean hasMoreElements() { return hasNext(); } - - public void compute() { } // default no-op CountedCompleter body - - /** - * Returns a batch value > 0 if this task should (and must) be - * split, if so, adding to pending count, and in any case - * updating batch value. The initial batch value is approx - * exp2 of the number of times (minus one) to split task by - * two before executing leaf action. This value is faster to - * compute and more convenient to use as a guide to splitting - * than is the depth, since it is used while dividing by two - * anyway. - */ - final int preSplit() { - ConcurrentHashMapV8 m; int b; Node[] t; ForkJoinPool pool; - if ((b = batch) < 0 && (m = map) != null) { // force initialization - if ((t = tab) == null && (t = tab = m.table) != null) - baseLimit = baseSize = t.length; - if (t != null) { - long n = m.sumCount(); - int par = ((pool = getPool()) == null) ? - ForkJoinPool.getCommonPoolParallelism() : - pool.getParallelism(); - int sp = par << 3; // slack of 8 - b = (n <= 0L) ? 0 : (n < (long)sp) ? (int)n : sp; - } - } - b = (b <= 1 || baseIndex == baseLimit) ? 0 : (b >>> 1); - if ((batch = b) > 0) - addToPendingCount(1); - return b; - } - - } /* ---------------- Public operations -------------- */ @@ -2431,7 +831,7 @@ public class ConcurrentHashMapV8 */ public ConcurrentHashMapV8(Map m) { this.sizeCtl = DEFAULT_CAPACITY; - internalPutAll(m); + putAll(m); } /** @@ -2472,7 +872,7 @@ public class ConcurrentHashMapV8 * nonpositive */ public ConcurrentHashMapV8(int initialCapacity, - float loadFactor, int concurrencyLevel) { + float loadFactor, int concurrencyLevel) { if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0) throw new IllegalArgumentException(); if (initialCapacity < concurrencyLevel) // Use at least as many bins @@ -2483,38 +883,7 @@ public class ConcurrentHashMapV8 this.sizeCtl = cap; } - /** - * Creates a new {@link Set} backed by a ConcurrentHashMapV8 - * from the given type to {@code Boolean.TRUE}. - * - * @return the new set - */ - public static KeySetView newKeySet() { - return new KeySetView(new ConcurrentHashMapV8(), - Boolean.TRUE); - } - - /** - * Creates a new {@link Set} backed by a ConcurrentHashMapV8 - * from the given type to {@code Boolean.TRUE}. - * - * @param initialCapacity The implementation performs internal - * sizing to accommodate this many elements. - * @throws IllegalArgumentException if the initial capacity of - * elements is negative - * @return the new set - */ - public static KeySetView newKeySet(int initialCapacity) { - return new KeySetView - (new ConcurrentHashMapV8(initialCapacity), Boolean.TRUE); - } - - /** - * {@inheritDoc} - */ - public boolean isEmpty() { - return sumCount() <= 0L; // ignore transient negative values - } + // Original (since JDK1.2) Map methods /** * {@inheritDoc} @@ -2527,17 +896,10 @@ public class ConcurrentHashMapV8 } /** - * Returns the number of mappings. This method should be used - * instead of {@link #size} because a ConcurrentHashMapV8 may - * contain more mappings than can be represented as an int. The - * value returned is an estimate; the actual count may differ if - * there are concurrent insertions or removals. - * - * @return the number of mappings + * {@inheritDoc} */ - public long mappingCount() { - long n = sumCount(); - return (n < 0L) ? 0L : n; // ignore transient negative values + public boolean isEmpty() { + return sumCount() <= 0L; // ignore transient negative values } /** @@ -2552,22 +914,23 @@ public class ConcurrentHashMapV8 * @throws NullPointerException if the specified key is null */ public V get(Object key) { - return internalGet(key); - } - - /** - * Returns the value to which the specified key is mapped, - * or the given defaultValue if this map contains no mapping for the key. - * - * @param key the key - * @param defaultValue the value to return if this map contains - * no mapping for the given key - * @return the mapping for the key, if present; else the defaultValue - * @throws NullPointerException if the specified key is null - */ - public V getValueOrDefault(Object key, V defaultValue) { - V v; - return (v = internalGet(key)) == null ? defaultValue : v; + Node[] tab; Node e, p; int n, eh; K ek; + int h = spread(key.hashCode()); + if ((tab = table) != null && (n = tab.length) > 0 && + (e = tabAt(tab, (n - 1) & h)) != null) { + if ((eh = e.hash) == h) { + if ((ek = e.key) == key || (ek != null && key.equals(ek))) + return e.val; + } + else if (eh < 0) + return (p = e.find(h, key)) != null ? p.val : null; + while ((e = e.next) != null) { + if (e.hash == h && + ((ek = e.key) == key || (ek != null && key.equals(ek)))) + return e.val; + } + } + return null; } /** @@ -2580,7 +943,7 @@ public class ConcurrentHashMapV8 * @throws NullPointerException if the specified key is null */ public boolean containsKey(Object key) { - return internalGet(key) != null; + return get(key) != null; } /** @@ -2596,34 +959,18 @@ public class ConcurrentHashMapV8 public boolean containsValue(Object value) { if (value == null) throw new NullPointerException(); - V v; - Traverser it = new Traverser(this); - while ((v = it.advance()) != null) { - if (v == value || value.equals(v)) - return true; + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + V v; + if ((v = p.val) == value || (v != null && value.equals(v))) + return true; + } } return false; } - /** - * Legacy method testing if some key maps into the specified value - * in this table. This method is identical in functionality to - * {@link #containsValue}, and exists solely to ensure - * full compatibility with class {@link java.util.Hashtable}, - * which supported this method prior to introduction of the - * Java Collections framework. - * - * @param value a value to search for - * @return {@code true} if and only if some key maps to the - * {@code value} argument in this table as - * determined by the {@code equals} method; - * {@code false} otherwise - * @throws NullPointerException if the specified value is null - */ - @Deprecated public boolean contains(Object value) { - return containsValue(value); - } - /** * Maps the specified key to the specified value in this table. * Neither the key nor the value can be null. @@ -2638,18 +985,72 @@ public class ConcurrentHashMapV8 * @throws NullPointerException if the specified key or value is null */ public V put(K key, V value) { - return internalPut(key, value, false); + return putVal(key, value, false); } - /** - * {@inheritDoc} - * - * @return the previous value associated with the specified key, - * or {@code null} if there was no mapping for the key - * @throws NullPointerException if the specified key or value is null - */ - public V putIfAbsent(K key, V value) { - return internalPut(key, value, true); + /** Implementation for put and putIfAbsent */ + final V putVal(K key, V value, boolean onlyIfAbsent) { + if (key == null || value == null) throw new NullPointerException(); + int hash = spread(key.hashCode()); + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & hash)) == null) { + if (casTabAt(tab, i, null, + new Node(hash, key, value, null))) + break; // no lock when adding to empty bin + } + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + V oldVal = null; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f;; ++binCount) { + K ek; + if (e.hash == hash && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + oldVal = e.val; + if (!onlyIfAbsent) + e.val = value; + break; + } + Node pred = e; + if ((e = e.next) == null) { + pred.next = new Node(hash, key, + value, null); + break; + } + } + } + else if (f instanceof TreeBin) { + Node p; + binCount = 2; + if ((p = ((TreeBin)f).putTreeVal(hash, key, + value)) != null) { + oldVal = p.val; + if (!onlyIfAbsent) + p.val = value; + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + if (oldVal != null) + return oldVal; + break; + } + } + } + addCount(1L, binCount); + return null; } /** @@ -2660,166 +1061,9 @@ public class ConcurrentHashMapV8 * @param m mappings to be stored in this map */ public void putAll(Map m) { - internalPutAll(m); - } - - /** - * If the specified key is not already associated with a value, - * computes its value using the given mappingFunction and enters - * it into the map unless null. This is equivalent to - * 
 {@code
-     * if (map.containsKey(key))
-     *   return map.get(key);
-     * value = mappingFunction.apply(key);
-     * if (value != null)
-     *   map.put(key, value);
-     * return value;}
- * - * except that the action is performed atomically. If the - * function returns {@code null} no mapping is recorded. If the - * function itself throws an (unchecked) exception, the exception - * is rethrown to its caller, and no mapping is recorded. Some - * attempted update operations on this map by other threads may be - * blocked while computation is in progress, so the computation - * should be short and simple, and must not attempt to update any - * other mappings of this Map. The most appropriate usage is to - * construct a new object serving as an initial mapped value, or - * memoized result, as in: - * - * 
 {@code
-     * map.computeIfAbsent(key, new Fun() {
-     *   public V map(K k) { return new Value(f(k)); }});}
- * - * @param key key with which the specified value is to be associated - * @param mappingFunction the function to compute a value - * @return the current (existing or computed) value associated with - * the specified key, or null if the computed value is null - * @throws NullPointerException if the specified key or mappingFunction - * is null - * @throws IllegalStateException if the computation detectably - * attempts a recursive update to this map that would - * otherwise never complete - * @throws RuntimeException or Error if the mappingFunction does so, - * in which case the mapping is left unestablished - */ - public V computeIfAbsent - (K key, Fun mappingFunction) { - return internalComputeIfAbsent(key, mappingFunction); - } - - /** - * If the given key is present, computes a new mapping value given a key and - * its current mapped value. This is equivalent to - * 
 {@code
-     *   if (map.containsKey(key)) {
-     *     value = remappingFunction.apply(key, map.get(key));
-     *     if (value != null)
-     *       map.put(key, value);
-     *     else
-     *       map.remove(key);
-     *   }
-     * }
- * - * except that the action is performed atomically. If the - * function returns {@code null}, the mapping is removed. If the - * function itself throws an (unchecked) exception, the exception - * is rethrown to its caller, and the current mapping is left - * unchanged. Some attempted update operations on this map by - * other threads may be blocked while computation is in progress, - * so the computation should be short and simple, and must not - * attempt to update any other mappings of this Map. For example, - * to either create or append new messages to a value mapping: - * - * @param key key with which the specified value is to be associated - * @param remappingFunction the function to compute a value - * @return the new value associated with the specified key, or null if none - * @throws NullPointerException if the specified key or remappingFunction - * is null - * @throws IllegalStateException if the computation detectably - * attempts a recursive update to this map that would - * otherwise never complete - * @throws RuntimeException or Error if the remappingFunction does so, - * in which case the mapping is unchanged - */ - public V computeIfPresent - (K key, BiFun remappingFunction) { - return internalCompute(key, true, remappingFunction); - } - - /** - * Computes a new mapping value given a key and - * its current mapped value (or {@code null} if there is no current - * mapping). This is equivalent to - * 
 {@code
-     *   value = remappingFunction.apply(key, map.get(key));
-     *   if (value != null)
-     *     map.put(key, value);
-     *   else
-     *     map.remove(key);
-     * }
- * - * except that the action is performed atomically. If the - * function returns {@code null}, the mapping is removed. If the - * function itself throws an (unchecked) exception, the exception - * is rethrown to its caller, and the current mapping is left - * unchanged. Some attempted update operations on this map by - * other threads may be blocked while computation is in progress, - * so the computation should be short and simple, and must not - * attempt to update any other mappings of this Map. For example, - * to either create or append new messages to a value mapping: - * - * 
 {@code
-     * Map map = ...;
-     * final String msg = ...;
-     * map.compute(key, new BiFun() {
-     *   public String apply(Key k, String v) {
-     *    return (v == null) ? msg : v + msg;});}}
- * - * @param key key with which the specified value is to be associated - * @param remappingFunction the function to compute a value - * @return the new value associated with the specified key, or null if none - * @throws NullPointerException if the specified key or remappingFunction - * is null - * @throws IllegalStateException if the computation detectably - * attempts a recursive update to this map that would - * otherwise never complete - * @throws RuntimeException or Error if the remappingFunction does so, - * in which case the mapping is unchanged - */ - public V compute - (K key, BiFun remappingFunction) { - return internalCompute(key, false, remappingFunction); - } - - /** - * If the specified key is not already associated - * with a value, associate it with the given value. - * Otherwise, replace the value with the results of - * the given remapping function. This is equivalent to: - * 
 {@code
-     *   if (!map.containsKey(key))
-     *     map.put(value);
-     *   else {
-     *     newValue = remappingFunction.apply(map.get(key), value);
-     *     if (value != null)
-     *       map.put(key, value);
-     *     else
-     *       map.remove(key);
-     *   }
-     * }
- * except that the action is performed atomically. If the - * function returns {@code null}, the mapping is removed. If the - * function itself throws an (unchecked) exception, the exception - * is rethrown to its caller, and the current mapping is left - * unchanged. Some attempted update operations on this map by - * other threads may be blocked while computation is in progress, - * so the computation should be short and simple, and must not - * attempt to update any other mappings of this Map. - */ - public V merge - (K key, V value, - BiFun remappingFunction) { - return internalMerge(key, value, remappingFunction); + tryPresize(m.size()); + for (Map.Entry e : m.entrySet()) + putVal(e.getKey(), e.getValue(), false); } /** @@ -2832,93 +1076,125 @@ public class ConcurrentHashMapV8 * @throws NullPointerException if the specified key is null */ public V remove(Object key) { - return internalReplace(key, null, null); + return replaceNode(key, null, null); } /** - * {@inheritDoc} - * - * @throws NullPointerException if the specified key is null + * Implementation for the four public remove/replace methods: + * Replaces node value with v, conditional upon match of cv if + * non-null. If resulting value is null, delete. */ - public boolean remove(Object key, Object value) { - return value != null && internalReplace(key, null, value) != null; - } - - /** - * {@inheritDoc} - * - * @throws NullPointerException if any of the arguments are null - */ - public boolean replace(K key, V oldValue, V newValue) { - if (key == null || oldValue == null || newValue == null) - throw new NullPointerException(); - return internalReplace(key, newValue, oldValue) != null; - } - - /** - * {@inheritDoc} - * - * @return the previous value associated with the specified key, - * or {@code null} if there was no mapping for the key - * @throws NullPointerException if the specified key or value is null - */ - public V replace(K key, V value) { - if (key == null || value == null) - throw new NullPointerException(); - return internalReplace(key, value, null); + final V replaceNode(Object key, V value, Object cv) { + int hash = spread(key.hashCode()); + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0 || + (f = tabAt(tab, i = (n - 1) & hash)) == null) + break; + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + V oldVal = null; + boolean validated = false; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + validated = true; + for (Node e = f, pred = null;;) { + K ek; + if (e.hash == hash && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + V ev = e.val; + if (cv == null || cv == ev || + (ev != null && cv.equals(ev))) { + oldVal = ev; + if (value != null) + e.val = value; + else if (pred != null) + pred.next = e.next; + else + setTabAt(tab, i, e.next); + } + break; + } + pred = e; + if ((e = e.next) == null) + break; + } + } + else if (f instanceof TreeBin) { + validated = true; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(hash, key, null)) != null) { + V pv = p.val; + if (cv == null || cv == pv || + (pv != null && cv.equals(pv))) { + oldVal = pv; + if (value != null) + p.val = value; + else if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + if (validated) { + if (oldVal != null) { + if (value == null) + addCount(-1L, -1); + return oldVal; + } + break; + } + } + } + return null; } /** * Removes all of the mappings from this map. */ public void clear() { - internalClear(); + long delta = 0L; // negative number of deletions + int i = 0; + Node[] tab = table; + while (tab != null && i < tab.length) { + int fh; + Node f = tabAt(tab, i); + if (f == null) + ++i; + else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + i = 0; // restart + } + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + Node p = (fh >= 0 ? f : + (f instanceof TreeBin) ? + ((TreeBin)f).first : null); + while (p != null) { + --delta; + p = p.next; + } + setTabAt(tab, i++, null); + } + } + } + } + if (delta != 0L) + addCount(delta, -1); } /** * Returns a {@link Set} view of the keys contained in this map. * The set is backed by the map, so changes to the map are - * reflected in the set, and vice-versa. - * - * @return the set view - */ - public KeySetView keySet() { - KeySetView ks = keySet; - return (ks != null) ? ks : (keySet = new KeySetView(this, null)); - } - - /** - * Returns a {@link Set} view of the keys in this map, using the - * given common mapped value for any additions (i.e., {@link - * Collection#add} and {@link Collection#addAll}). This is of - * course only appropriate if it is acceptable to use the same - * value for all additions from this view. - * - * @param mappedValue the mapped value to use for any additions - * @return the set view - * @throws NullPointerException if the mappedValue is null - */ - public KeySetView keySet(V mappedValue) { - if (mappedValue == null) - throw new NullPointerException(); - return new KeySetView(this, mappedValue); - } - - /** - * Returns a {@link Collection} view of the values contained in this map. - * The collection is backed by the map, so changes to the map are - * reflected in the collection, and vice-versa. - */ - public ValuesView values() { - ValuesView vs = values; - return (vs != null) ? vs : (values = new ValuesView(this)); - } - - /** - * Returns a {@link Set} view of the mappings contained in this map. - * The set is backed by the map, so changes to the map are - * reflected in the set, and vice-versa. The set supports element - * removal, which removes the corresponding mapping from the map, + * reflected in the set, and vice-versa. The set supports element + * removal, which removes the corresponding mapping from this map, * via the {@code Iterator.remove}, {@code Set.remove}, * {@code removeAll}, {@code retainAll}, and {@code clear} * operations. It does not support the {@code add} or @@ -2929,57 +1205,57 @@ public class ConcurrentHashMapV8 * and guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not guaranteed to) * reflect any modifications subsequent to construction. + * + * @return the set view + */ + public KeySetView keySet() { + KeySetView ks; + return (ks = keySet) != null ? ks : (keySet = new KeySetView(this, null)); + } + + /** + * Returns a {@link Collection} view of the values contained in this map. + * The collection is backed by the map, so changes to the map are + * reflected in the collection, and vice-versa. The collection + * supports element removal, which removes the corresponding + * mapping from this map, via the {@code Iterator.remove}, + * {@code Collection.remove}, {@code removeAll}, + * {@code retainAll}, and {@code clear} operations. It does not + * support the {@code add} or {@code addAll} operations. + * + *

The view's {@code iterator} is a "weakly consistent" iterator + * that will never throw {@link ConcurrentModificationException}, + * and guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not guaranteed to) + * reflect any modifications subsequent to construction. + * + * @return the collection view + */ + public Collection values() { + ValuesView vs; + return (vs = values) != null ? vs : (values = new ValuesView(this)); + } + + /** + * Returns a {@link Set} view of the mappings contained in this map. + * The set is backed by the map, so changes to the map are + * reflected in the set, and vice-versa. The set supports element + * removal, which removes the corresponding mapping from the map, + * via the {@code Iterator.remove}, {@code Set.remove}, + * {@code removeAll}, {@code retainAll}, and {@code clear} + * operations. + * + *

The view's {@code iterator} is a "weakly consistent" iterator + * that will never throw {@link ConcurrentModificationException}, + * and guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not guaranteed to) + * reflect any modifications subsequent to construction. + * + * @return the set view */ public Set> entrySet() { - EntrySetView es = entrySet; - return (es != null) ? es : (entrySet = new EntrySetView(this)); - } - - /** - * Returns an enumeration of the keys in this table. - * - * @return an enumeration of the keys in this table - * @see #keySet() - */ - public Enumeration keys() { - return new KeyIterator(this); - } - - /** - * Returns an enumeration of the values in this table. - * - * @return an enumeration of the values in this table - * @see #values() - */ - public Enumeration elements() { - return new ValueIterator(this); - } - - /** - * Returns a partitionable iterator of the keys in this map. - * - * @return a partitionable iterator of the keys in this map - */ - public Spliterator keySpliterator() { - return new KeyIterator(this); - } - - /** - * Returns a partitionable iterator of the values in this map. - * - * @return a partitionable iterator of the values in this map - */ - public Spliterator valueSpliterator() { - return new ValueIterator(this); - } - - /** - * Returns a partitionable iterator of the entries in this map. - * - * @return a partitionable iterator of the entries in this map - */ - public Spliterator> entrySpliterator() { - return new EntryIterator(this); + EntrySetView es; + return (es = entrySet) != null ? es : (entrySet = new EntrySetView(this)); } /** @@ -2991,10 +1267,11 @@ public class ConcurrentHashMapV8 */ public int hashCode() { int h = 0; - Traverser it = new Traverser(this); - V v; - while ((v = it.advance()) != null) { - h += it.nextKey.hashCode() ^ v.hashCode(); + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + h += p.key.hashCode() ^ p.val.hashCode(); } return h; } @@ -3011,17 +1288,20 @@ public class ConcurrentHashMapV8 * @return a string representation of this map */ public String toString() { - Traverser it = new Traverser(this); + Node[] t; + int f = (t = table) == null ? 0 : t.length; + Traverser it = new Traverser(t, f, 0, f); StringBuilder sb = new StringBuilder(); sb.append('{'); - V v; - if ((v = it.advance()) != null) { + Node p; + if ((p = it.advance()) != null) { for (;;) { - Object k = it.nextKey; + K k = p.key; + V v = p.val; sb.append(k == this ? "(this Map)" : k); sb.append('='); sb.append(v == this ? "(this Map)" : v); - if ((v = it.advance()) == null) + if ((p = it.advance()) == null) break; sb.append(',').append(' '); } @@ -3044,10 +1324,12 @@ public class ConcurrentHashMapV8 if (!(o instanceof Map)) return false; Map m = (Map) o; - Traverser it = new Traverser(this); - V val; - while ((val = it.advance()) != null) { - Object v = m.get(it.nextKey); + Node[] t; + int f = (t = table) == null ? 0 : t.length; + Traverser it = new Traverser(t, f, 0, f); + for (Node p; (p = it.advance()) != null; ) { + V val = p.val; + Object v = m.get(p.key); if (v == null || (v != val && !v.equals(val))) return false; } @@ -3055,7 +1337,7 @@ public class ConcurrentHashMapV8 Object mk, mv, v; if ((mk = e.getKey()) == null || (mv = e.getValue()) == null || - (v = internalGet(mk)) == null || + (v = get(mk)) == null || (mv != v && !mv.equals(v))) return false; } @@ -3063,136 +1345,11 @@ public class ConcurrentHashMapV8 return true; } - /* ----------------Iterators -------------- */ - - @SuppressWarnings("serial") static final class KeyIterator - extends Traverser - implements Spliterator, Enumeration { - KeyIterator(ConcurrentHashMapV8 map) { super(map); } - KeyIterator(ConcurrentHashMapV8 map, Traverser it) { - super(map, it, -1); - } - public KeyIterator split() { - if (nextKey != null) - throw new IllegalStateException(); - return new KeyIterator(map, this); - } - @SuppressWarnings("unchecked") public final K next() { - if (nextVal == null && advance() == null) - throw new NoSuchElementException(); - Object k = nextKey; - nextVal = null; - return (K) k; - } - - public final K nextElement() { return next(); } - } - - @SuppressWarnings("serial") static final class ValueIterator - extends Traverser - implements Spliterator, Enumeration { - ValueIterator(ConcurrentHashMapV8 map) { super(map); } - ValueIterator(ConcurrentHashMapV8 map, Traverser it) { - super(map, it, -1); - } - public ValueIterator split() { - if (nextKey != null) - throw new IllegalStateException(); - return new ValueIterator(map, this); - } - - public final V next() { - V v; - if ((v = nextVal) == null && (v = advance()) == null) - throw new NoSuchElementException(); - nextVal = null; - return v; - } - - public final V nextElement() { return next(); } - } - - @SuppressWarnings("serial") static final class EntryIterator - extends Traverser - implements Spliterator> { - EntryIterator(ConcurrentHashMapV8 map) { super(map); } - EntryIterator(ConcurrentHashMapV8 map, Traverser it) { - super(map, it, -1); - } - public EntryIterator split() { - if (nextKey != null) - throw new IllegalStateException(); - return new EntryIterator(map, this); - } - - @SuppressWarnings("unchecked") public final Map.Entry next() { - V v; - if ((v = nextVal) == null && (v = advance()) == null) - throw new NoSuchElementException(); - Object k = nextKey; - nextVal = null; - return new MapEntry((K)k, v, map); - } - } - - /** - * Exported Entry for iterators - */ - static final class MapEntry implements Map.Entry { - final K key; // non-null - V val; // non-null - final ConcurrentHashMapV8 map; - MapEntry(K key, V val, ConcurrentHashMapV8 map) { - this.key = key; - this.val = val; - this.map = map; - } - public final K getKey() { return key; } - public final V getValue() { return val; } - public final int hashCode() { return key.hashCode() ^ val.hashCode(); } - public final String toString(){ return key + "=" + val; } - - public final boolean equals(Object o) { - Object k, v; Map.Entry e; - return ((o instanceof Map.Entry) && - (k = (e = (Map.Entry)o).getKey()) != null && - (v = e.getValue()) != null && - (k == key || k.equals(key)) && - (v == val || v.equals(val))); - } - - /** - * Sets our entry's value and writes through to the map. The - * value to return is somewhat arbitrary here. Since we do not - * necessarily track asynchronous changes, the most recent - * "previous" value could be different from what we return (or - * could even have been removed in which case the put will - * re-establish). We do not and cannot guarantee more. - */ - public final V setValue(V value) { - if (value == null) throw new NullPointerException(); - V v = val; - val = value; - map.put(key, value); - return v; - } - } - - /** - * Returns exportable snapshot entry for the given key and value - * when write-through can't or shouldn't be used. - */ - static AbstractMap.SimpleEntry entryFor(K k, V v) { - return new AbstractMap.SimpleEntry(k, v); - } - - /* ---------------- Serialization Support -------------- */ - /** * Stripped-down version of helper class used in previous version, * declared for the sake of serialization compatibility */ - static class Segment implements Serializable { + static class Segment extends ReentrantLock implements Serializable { private static final long serialVersionUID = 2249069246763182397L; final float loadFactor; Segment(float lf) { this.loadFactor = lf; } @@ -3207,21 +1364,34 @@ public class ConcurrentHashMapV8 * for each key-value mapping, followed by a null pair. * The key-value mappings are emitted in no particular order. */ - @SuppressWarnings("unchecked") private void writeObject - (java.io.ObjectOutputStream s) + private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException { - if (segments == null) { // for serialization compatibility - segments = (Segment[]) - new Segment[DEFAULT_CONCURRENCY_LEVEL]; - for (int i = 0; i < segments.length; ++i) - segments[i] = new Segment(LOAD_FACTOR); + // For serialization compatibility + // Emulate segment calculation from previous version of this class + int sshift = 0; + int ssize = 1; + while (ssize < DEFAULT_CONCURRENCY_LEVEL) { + ++sshift; + ssize <<= 1; } - s.defaultWriteObject(); - Traverser it = new Traverser(this); - V v; - while ((v = it.advance()) != null) { - s.writeObject(it.nextKey); - s.writeObject(v); + int segmentShift = 32 - sshift; + int segmentMask = ssize - 1; + @SuppressWarnings("unchecked") Segment[] segments = (Segment[]) + new Segment[DEFAULT_CONCURRENCY_LEVEL]; + for (int i = 0; i < segments.length; ++i) + segments[i] = new Segment(LOAD_FACTOR); + s.putFields().put("segments", segments); + s.putFields().put("segmentShift", segmentShift); + s.putFields().put("segmentMask", segmentMask); + s.writeFields(); + + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + s.writeObject(p.key); + s.writeObject(p.val); + } } s.writeObject(null); s.writeObject(null); @@ -3232,28 +1402,32 @@ public class ConcurrentHashMapV8 * Reconstitutes the instance from a stream (that is, deserializes it). * @param s the stream */ - @SuppressWarnings("unchecked") private void readObject - (java.io.ObjectInputStream s) + private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { + /* + * To improve performance in typical cases, we create nodes + * while reading, then place in table once size is known. + * However, we must also validate uniqueness and deal with + * overpopulated bins while doing so, which requires + * specialized versions of putVal mechanics. + */ + sizeCtl = -1; // force exclusion for table construction s.defaultReadObject(); - this.segments = null; // unneeded - - // Create all nodes, then place in table once size is known long size = 0L; - Node p = null; + Node p = null; for (;;) { - K k = (K) s.readObject(); - V v = (V) s.readObject(); + @SuppressWarnings("unchecked") K k = (K) s.readObject(); + @SuppressWarnings("unchecked") V v = (V) s.readObject(); if (k != null && v != null) { - int h = spread(k.hashCode()); - p = new Node(h, k, v, p); + p = new Node(spread(k.hashCode()), k, v, p); ++size; } else break; } - if (p != null) { - boolean init = false; + if (size == 0L) + sizeCtl = 0; + else { int n; if (size >= (long)(MAXIMUM_CAPACITY >>> 1)) n = MAXIMUM_CAPACITY; @@ -3261,810 +1435,2022 @@ public class ConcurrentHashMapV8 int sz = (int)size; n = tableSizeFor(sz + (sz >>> 1) + 1); } - int sc = sizeCtl; - boolean collide = false; - if (n > sc && - U.compareAndSwapInt(this, SIZECTL, sc, -1)) { - try { - if (table == null) { - init = true; - @SuppressWarnings("rawtypes") Node[] rt = new Node[n]; - Node[] tab = (Node[])rt; - int mask = n - 1; - while (p != null) { - int j = p.hash & mask; - Node next = p.next; - Node q = p.next = tabAt(tab, j); - setTabAt(tab, j, p); - if (!collide && q != null && q.hash == p.hash) - collide = true; - p = next; + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] tab = (Node[])new Node[n]; + int mask = n - 1; + long added = 0L; + while (p != null) { + boolean insertAtFront; + Node next = p.next, first; + int h = p.hash, j = h & mask; + if ((first = tabAt(tab, j)) == null) + insertAtFront = true; + else { + K k = p.key; + if (first.hash < 0) { + TreeBin t = (TreeBin)first; + if (t.putTreeVal(h, k, p.val) == null) + ++added; + insertAtFront = false; + } + else { + int binCount = 0; + insertAtFront = true; + Node q; K qk; + for (q = first; q != null; q = q.next) { + if (q.hash == h && + ((qk = q.key) == k || + (qk != null && k.equals(qk)))) { + insertAtFront = false; + break; + } + ++binCount; } - table = tab; - addCount(size, -1); + if (insertAtFront && binCount >= TREEIFY_THRESHOLD) { + insertAtFront = false; + ++added; + p.next = first; + TreeNode hd = null, tl = null; + for (q = p; q != null; q = q.next) { + TreeNode t = new TreeNode + (q.hash, q.key, q.val, null, null); + if ((t.prev = tl) == null) + hd = t; + else + tl.next = t; + tl = t; + } + setTabAt(tab, j, new TreeBin(hd)); + } + } + } + if (insertAtFront) { + ++added; + p.next = first; + setTabAt(tab, j, p); + } + p = next; + } + table = tab; + sizeCtl = n - (n >>> 2); + baseCount = added; + } + } + + // ConcurrentMap methods + + /** + * {@inheritDoc} + * + * @return the previous value associated with the specified key, + * or {@code null} if there was no mapping for the key + * @throws NullPointerException if the specified key or value is null + */ + public V putIfAbsent(K key, V value) { + return putVal(key, value, true); + } + + /** + * {@inheritDoc} + * + * @throws NullPointerException if the specified key is null + */ + public boolean remove(Object key, Object value) { + if (key == null) + throw new NullPointerException(); + return value != null && replaceNode(key, null, value) != null; + } + + /** + * {@inheritDoc} + * + * @throws NullPointerException if any of the arguments are null + */ + public boolean replace(K key, V oldValue, V newValue) { + if (key == null || oldValue == null || newValue == null) + throw new NullPointerException(); + return replaceNode(key, newValue, oldValue) != null; + } + + /** + * {@inheritDoc} + * + * @return the previous value associated with the specified key, + * or {@code null} if there was no mapping for the key + * @throws NullPointerException if the specified key or value is null + */ + public V replace(K key, V value) { + if (key == null || value == null) + throw new NullPointerException(); + return replaceNode(key, value, null); + } + + // Overrides of JDK8+ Map extension method defaults + + /** + * Returns the value to which the specified key is mapped, or the + * given default value if this map contains no mapping for the + * key. + * + * @param key the key whose associated value is to be returned + * @param defaultValue the value to return if this map contains + * no mapping for the given key + * @return the mapping for the key, if present; else the default value + * @throws NullPointerException if the specified key is null + */ + public V getOrDefault(Object key, V defaultValue) { + V v; + return (v = get(key)) == null ? defaultValue : v; + } + + public void forEach(BiAction action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + action.apply(p.key, p.val); + } + } + } + + public void replaceAll(BiFun function) { + if (function == null) throw new NullPointerException(); + Node[] t; + if ((t = table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + V oldValue = p.val; + for (K key = p.key;;) { + V newValue = function.apply(key, oldValue); + if (newValue == null) + throw new NullPointerException(); + if (replaceNode(key, newValue, oldValue) != null || + (oldValue = get(key)) == null) + break; + } + } + } + } + + /** + * If the specified key is not already associated with a value, + * attempts to compute its value using the given mapping function + * and enters it into this map unless {@code null}. The entire + * method invocation is performed atomically, so the function is + * applied at most once per key. Some attempted update operations + * on this map by other threads may be blocked while computation + * is in progress, so the computation should be short and simple, + * and must not attempt to update any other mappings of this map. + * + * @param key key with which the specified value is to be associated + * @param mappingFunction the function to compute a value + * @return the current (existing or computed) value associated with + * the specified key, or null if the computed value is null + * @throws NullPointerException if the specified key or mappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the mappingFunction does so, + * in which case the mapping is left unestablished + */ + public V computeIfAbsent(K key, Fun mappingFunction) { + if (key == null || mappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) { + Node r = new ReservationNode(); + synchronized (r) { + if (casTabAt(tab, i, null, r)) { + binCount = 1; + Node node = null; + try { + if ((val = mappingFunction.apply(key)) != null) + node = new Node(h, key, val, null); + } finally { + setTabAt(tab, i, node); + } + } + } + if (binCount != 0) + break; + } + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + boolean added = false; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f;; ++binCount) { + K ek; V ev; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = e.val; + break; + } + Node pred = e; + if ((e = e.next) == null) { + if ((val = mappingFunction.apply(key)) != null) { + added = true; + pred.next = new Node(h, key, val, null); + } + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(h, key, null)) != null) + val = p.val; + else if ((val = mappingFunction.apply(key)) != null) { + added = true; + t.putTreeVal(h, key, val); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + if (!added) + return val; + break; + } + } + } + if (val != null) + addCount(1L, binCount); + return val; + } + + /** + * If the value for the specified key is present, attempts to + * compute a new mapping given the key and its current mapped + * value. The entire method invocation is performed atomically. + * Some attempted update operations on this map by other threads + * may be blocked while computation is in progress, so the + * computation should be short and simple, and must not attempt to + * update any other mappings of this map. + * + * @param key key with which a value may be associated + * @param remappingFunction the function to compute a value + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or remappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V computeIfPresent(K key, BiFun remappingFunction) { + if (key == null || remappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) + break; + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = remappingFunction.apply(key, e.val); + if (val != null) + e.val = val; + else { + delta = -1; + Node en = e.next; + if (pred != null) + pred.next = en; + else + setTabAt(tab, i, en); + } + break; + } + pred = e; + if ((e = e.next) == null) + break; + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(h, key, null)) != null) { + val = remappingFunction.apply(key, p.val); + if (val != null) + p.val = val; + else { + delta = -1; + if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + if (binCount != 0) + break; + } + } + if (delta != 0) + addCount((long)delta, binCount); + return val; + } + + /** + * Attempts to compute a mapping for the specified key and its + * current mapped value (or {@code null} if there is no current + * mapping). The entire method invocation is performed atomically. + * Some attempted update operations on this map by other threads + * may be blocked while computation is in progress, so the + * computation should be short and simple, and must not attempt to + * update any other mappings of this Map. + * + * @param key key with which the specified value is to be associated + * @param remappingFunction the function to compute a value + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or remappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V compute(K key, + BiFun remappingFunction) { + if (key == null || remappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) { + Node r = new ReservationNode(); + synchronized (r) { + if (casTabAt(tab, i, null, r)) { + binCount = 1; + Node node = null; + try { + if ((val = remappingFunction.apply(key, null)) != null) { + delta = 1; + node = new Node(h, key, val, null); + } + } finally { + setTabAt(tab, i, node); + } + } + } + if (binCount != 0) + break; + } + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = remappingFunction.apply(key, e.val); + if (val != null) + e.val = val; + else { + delta = -1; + Node en = e.next; + if (pred != null) + pred.next = en; + else + setTabAt(tab, i, en); + } + break; + } + pred = e; + if ((e = e.next) == null) { + val = remappingFunction.apply(key, null); + if (val != null) { + delta = 1; + pred.next = + new Node(h, key, val, null); + } + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 1; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null) + p = r.findTreeNode(h, key, null); + else + p = null; + V pv = (p == null) ? null : p.val; + val = remappingFunction.apply(key, pv); + if (val != null) { + if (p != null) + p.val = val; + else { + delta = 1; + t.putTreeVal(h, key, val); + } + } + else if (p != null) { + delta = -1; + if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + break; + } + } + } + if (delta != 0) + addCount((long)delta, binCount); + return val; + } + + /** + * If the specified key is not already associated with a + * (non-null) value, associates it with the given value. + * Otherwise, replaces the value with the results of the given + * remapping function, or removes if {@code null}. The entire + * method invocation is performed atomically. Some attempted + * update operations on this map by other threads may be blocked + * while computation is in progress, so the computation should be + * short and simple, and must not attempt to update any other + * mappings of this Map. + * + * @param key key with which the specified value is to be associated + * @param value the value to use if absent + * @param remappingFunction the function to recompute a value if present + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or the + * remappingFunction is null + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V merge(K key, V value, BiFun remappingFunction) { + if (key == null || value == null || remappingFunction == null) + throw new NullPointerException(); + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) + tab = initTable(); + else if ((f = tabAt(tab, i = (n - 1) & h)) == null) { + if (casTabAt(tab, i, null, new Node(h, key, value, null))) { + delta = 1; + val = value; + break; + } + } + else if ((fh = f.hash) == MOVED) + tab = helpTransfer(tab, f); + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + (ek != null && key.equals(ek)))) { + val = remappingFunction.apply(e.val, value); + if (val != null) + e.val = val; + else { + delta = -1; + Node en = e.next; + if (pred != null) + pred.next = en; + else + setTabAt(tab, i, en); + } + break; + } + pred = e; + if ((e = e.next) == null) { + delta = 1; + val = value; + pred.next = + new Node(h, key, val, null); + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r = t.root; + TreeNode p = (r == null) ? null : + r.findTreeNode(h, key, null); + val = (p == null) ? value : + remappingFunction.apply(p.val, value); + if (val != null) { + if (p != null) + p.val = val; + else { + delta = 1; + t.putTreeVal(h, key, val); + } + } + else if (p != null) { + delta = -1; + if (t.removeTreeNode(p)) + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) + treeifyBin(tab, i); + break; + } + } + } + if (delta != 0) + addCount((long)delta, binCount); + return val; + } + + // Hashtable legacy methods + + /** + * Legacy method testing if some key maps into the specified value + * in this table. This method is identical in functionality to + * {@link #containsValue(Object)}, and exists solely to ensure + * full compatibility with class {@link java.util.Hashtable}, + * which supported this method prior to introduction of the + * Java Collections framework. + * + * @param value a value to search for + * @return {@code true} if and only if some key maps to the + * {@code value} argument in this table as + * determined by the {@code equals} method; + * {@code false} otherwise + * @throws NullPointerException if the specified value is null + */ + @Deprecated public boolean contains(Object value) { + return containsValue(value); + } + + /** + * Returns an enumeration of the keys in this table. + * + * @return an enumeration of the keys in this table + * @see #keySet() + */ + public Enumeration keys() { + Node[] t; + int f = (t = table) == null ? 0 : t.length; + return new KeyIterator(t, f, 0, f, this); + } + + /** + * Returns an enumeration of the values in this table. + * + * @return an enumeration of the values in this table + * @see #values() + */ + public Enumeration elements() { + Node[] t; + int f = (t = table) == null ? 0 : t.length; + return new ValueIterator(t, f, 0, f, this); + } + + // ConcurrentHashMapV8-only methods + + /** + * Returns the number of mappings. This method should be used + * instead of {@link #size} because a ConcurrentHashMapV8 may + * contain more mappings than can be represented as an int. The + * value returned is an estimate; the actual count may differ if + * there are concurrent insertions or removals. + * + * @return the number of mappings + * @since 1.8 + */ + public long mappingCount() { + long n = sumCount(); + return (n < 0L) ? 0L : n; // ignore transient negative values + } + + /** + * Creates a new {@link Set} backed by a ConcurrentHashMapV8 + * from the given type to {@code Boolean.TRUE}. + * + * @return the new set + * @since 1.8 + */ + public static KeySetView newKeySet() { + return new KeySetView + (new ConcurrentHashMapV8(), Boolean.TRUE); + } + + /** + * Creates a new {@link Set} backed by a ConcurrentHashMapV8 + * from the given type to {@code Boolean.TRUE}. + * + * @param initialCapacity The implementation performs internal + * sizing to accommodate this many elements. + * @throws IllegalArgumentException if the initial capacity of + * elements is negative + * @return the new set + * @since 1.8 + */ + public static KeySetView newKeySet(int initialCapacity) { + return new KeySetView + (new ConcurrentHashMapV8(initialCapacity), Boolean.TRUE); + } + + /** + * Returns a {@link Set} view of the keys in this map, using the + * given common mapped value for any additions (i.e., {@link + * Collection#add} and {@link Collection#addAll(Collection)}). + * This is of course only appropriate if it is acceptable to use + * the same value for all additions from this view. + * + * @param mappedValue the mapped value to use for any additions + * @return the set view + * @throws NullPointerException if the mappedValue is null + */ + public KeySetView keySet(V mappedValue) { + if (mappedValue == null) + throw new NullPointerException(); + return new KeySetView(this, mappedValue); + } + + /* ---------------- Special Nodes -------------- */ + + /** + * A node inserted at head of bins during transfer operations. + */ + static final class ForwardingNode extends Node { + final Node[] nextTable; + ForwardingNode(Node[] tab) { + super(MOVED, null, null, null); + this.nextTable = tab; + } + + Node find(int h, Object k) { + // loop to avoid arbitrarily deep recursion on forwarding nodes + outer: for (Node[] tab = nextTable;;) { + Node e; int n; + if (k == null || tab == null || (n = tab.length) == 0 || + (e = tabAt(tab, (n - 1) & h)) == null) + return null; + for (;;) { + int eh; K ek; + if ((eh = e.hash) == h && + ((ek = e.key) == k || (ek != null && k.equals(ek)))) + return e; + if (eh < 0) { + if (e instanceof ForwardingNode) { + tab = ((ForwardingNode)e).nextTable; + continue outer; + } + else + return e.find(h, k); + } + if ((e = e.next) == null) + return null; + } + } + } + } + + /** + * A place-holder node used in computeIfAbsent and compute + */ + static final class ReservationNode extends Node { + ReservationNode() { + super(RESERVED, null, null, null); + } + + Node find(int h, Object k) { + return null; + } + } + + /* ---------------- Table Initialization and Resizing -------------- */ + + /** + * Initializes table, using the size recorded in sizeCtl. + */ + private final Node[] initTable() { + Node[] tab; int sc; + while ((tab = table) == null || tab.length == 0) { + if ((sc = sizeCtl) < 0) + Thread.yield(); // lost initialization race; just spin + else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { + try { + if ((tab = table) == null || tab.length == 0) { + int n = (sc > 0) ? sc : DEFAULT_CAPACITY; + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = (Node[])new Node[n]; + table = tab = nt; sc = n - (n >>> 2); } } finally { sizeCtl = sc; } - if (collide) { // rescan and convert to TreeBins - Node[] tab = table; - for (int i = 0; i < tab.length; ++i) { - int c = 0; - for (Node e = tabAt(tab, i); e != null; e = e.next) { - if (++c > TREE_THRESHOLD && - (e.key instanceof Comparable)) { - replaceWithTreeBin(tab, i, e.key); - break; + break; + } + } + return tab; + } + + /** + * Adds to count, and if table is too small and not already + * resizing, initiates transfer. If already resizing, helps + * perform transfer if work is available. Rechecks occupancy + * after a transfer to see if another resize is already needed + * because resizings are lagging additions. + * + * @param x the count to add + * @param check if <0, don't check resize, if <= 1 only check if uncontended + */ + private final void addCount(long x, int check) { + CounterCell[] as; long b, s; + if ((as = counterCells) != null || + !U.compareAndSwapLong(this, BASECOUNT, b = baseCount, s = b + x)) { + CounterHashCode hc; CounterCell a; long v; int m; + boolean uncontended = true; + if ((hc = threadCounterHashCode.get()) == null || + as == null || (m = as.length - 1) < 0 || + (a = as[m & hc.code]) == null || + !(uncontended = + U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) { + fullAddCount(x, hc, uncontended); + return; + } + if (check <= 1) + return; + s = sumCount(); + } + if (check >= 0) { + Node[] tab, nt; int sc; + while (s >= (long)(sc = sizeCtl) && (tab = table) != null && + tab.length < MAXIMUM_CAPACITY) { + if (sc < 0) { + if (sc == -1 || transferIndex <= transferOrigin || + (nt = nextTable) == null) + break; + if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) + transfer(tab, nt); + } + else if (U.compareAndSwapInt(this, SIZECTL, sc, -2)) + transfer(tab, null); + s = sumCount(); + } + } + } + + /** + * Helps transfer if a resize is in progress. + */ + final Node[] helpTransfer(Node[] tab, Node f) { + Node[] nextTab; int sc; + if ((f instanceof ForwardingNode) && + (nextTab = ((ForwardingNode)f).nextTable) != null) { + if (nextTab == nextTable && tab == table && + transferIndex > transferOrigin && (sc = sizeCtl) < -1 && + U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) + transfer(tab, nextTab); + return nextTab; + } + return table; + } + + /** + * Tries to presize table to accommodate the given number of elements. + * + * @param size number of elements (doesn't need to be perfectly accurate) + */ + private final void tryPresize(int size) { + int c = (size >= (MAXIMUM_CAPACITY >>> 1)) ? MAXIMUM_CAPACITY : + tableSizeFor(size + (size >>> 1) + 1); + int sc; + while ((sc = sizeCtl) >= 0) { + Node[] tab = table; int n; + if (tab == null || (n = tab.length) == 0) { + n = (sc > c) ? sc : c; + if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { + try { + if (table == tab) { + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = (Node[])new Node[n]; + table = nt; + sc = n - (n >>> 2); + } + } finally { + sizeCtl = sc; + } + } + } + else if (c <= sc || n >= MAXIMUM_CAPACITY) + break; + else if (tab == table && + U.compareAndSwapInt(this, SIZECTL, sc, -2)) + transfer(tab, null); + } + } + + /** + * Moves and/or copies the nodes in each bin to new table. See + * above for explanation. + */ + private final void transfer(Node[] tab, Node[] nextTab) { + int n = tab.length, stride; + if ((stride = (NCPU > 1) ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE) + stride = MIN_TRANSFER_STRIDE; // subdivide range + if (nextTab == null) { // initiating + try { + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = (Node[])new Node[n << 1]; + nextTab = nt; + } catch (Throwable ex) { // try to cope with OOME + sizeCtl = Integer.MAX_VALUE; + return; + } + nextTable = nextTab; + transferOrigin = n; + transferIndex = n; + ForwardingNode rev = new ForwardingNode(tab); + for (int k = n; k > 0;) { // progressively reveal ready slots + int nextk = (k > stride) ? k - stride : 0; + for (int m = nextk; m < k; ++m) + nextTab[m] = rev; + for (int m = n + nextk; m < n + k; ++m) + nextTab[m] = rev; + U.putOrderedInt(this, TRANSFERORIGIN, k = nextk); + } + } + int nextn = nextTab.length; + ForwardingNode fwd = new ForwardingNode(nextTab); + boolean advance = true; + boolean finishing = false; // to ensure sweep before committing nextTab + for (int i = 0, bound = 0;;) { + int nextIndex, nextBound, fh; Node f; + while (advance) { + if (--i >= bound || finishing) + advance = false; + else if ((nextIndex = transferIndex) <= transferOrigin) { + i = -1; + advance = false; + } + else if (U.compareAndSwapInt + (this, TRANSFERINDEX, nextIndex, + nextBound = (nextIndex > stride ? + nextIndex - stride : 0))) { + bound = nextBound; + i = nextIndex - 1; + advance = false; + } + } + if (i < 0 || i >= n || i + n >= nextn) { + if (finishing) { + nextTable = null; + table = nextTab; + sizeCtl = (n << 1) - (n >>> 1); + return; + } + for (int sc;;) { + if (U.compareAndSwapInt(this, SIZECTL, sc = sizeCtl, ++sc)) { + if (sc != -1) + return; + finishing = advance = true; + i = n; // recheck before commit + break; + } + } + } + else if ((f = tabAt(tab, i)) == null) { + if (casTabAt(tab, i, null, fwd)) { + setTabAt(nextTab, i, null); + setTabAt(nextTab, i + n, null); + advance = true; + } + } + else if ((fh = f.hash) == MOVED) + advance = true; // already processed + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + Node ln, hn; + if (fh >= 0) { + int runBit = fh & n; + Node lastRun = f; + for (Node p = f.next; p != null; p = p.next) { + int b = p.hash & n; + if (b != runBit) { + runBit = b; + lastRun = p; + } + } + if (runBit == 0) { + ln = lastRun; + hn = null; + } + else { + hn = lastRun; + ln = null; + } + for (Node p = f; p != lastRun; p = p.next) { + int ph = p.hash; K pk = p.key; V pv = p.val; + if ((ph & n) == 0) + ln = new Node(ph, pk, pv, ln); + else + hn = new Node(ph, pk, pv, hn); + } + setTabAt(nextTab, i, ln); + setTabAt(nextTab, i + n, hn); + setTabAt(tab, i, fwd); + advance = true; + } + else if (f instanceof TreeBin) { + TreeBin t = (TreeBin)f; + TreeNode lo = null, loTail = null; + TreeNode hi = null, hiTail = null; + int lc = 0, hc = 0; + for (Node e = t.first; e != null; e = e.next) { + int h = e.hash; + TreeNode p = new TreeNode + (h, e.key, e.val, null, null); + if ((h & n) == 0) { + if ((p.prev = loTail) == null) + lo = p; + else + loTail.next = p; + loTail = p; + ++lc; + } + else { + if ((p.prev = hiTail) == null) + hi = p; + else + hiTail.next = p; + hiTail = p; + ++hc; + } + } + ln = (lc <= UNTREEIFY_THRESHOLD) ? untreeify(lo) : + (hc != 0) ? new TreeBin(lo) : t; + hn = (hc <= UNTREEIFY_THRESHOLD) ? untreeify(hi) : + (lc != 0) ? new TreeBin(hi) : t; + setTabAt(nextTab, i, ln); + setTabAt(nextTab, i + n, hn); + setTabAt(tab, i, fwd); + advance = true; + } + } + } + } + } + } + + /* ---------------- Conversion from/to TreeBins -------------- */ + + /** + * Replaces all linked nodes in bin at given index unless table is + * too small, in which case resizes instead. + */ + private final void treeifyBin(Node[] tab, int index) { + Node b; int n, sc; + if (tab != null) { + if ((n = tab.length) < MIN_TREEIFY_CAPACITY) { + if (tab == table && (sc = sizeCtl) >= 0 && + U.compareAndSwapInt(this, SIZECTL, sc, -2)) + transfer(tab, null); + } + else if ((b = tabAt(tab, index)) != null && b.hash >= 0) { + synchronized (b) { + if (tabAt(tab, index) == b) { + TreeNode hd = null, tl = null; + for (Node e = b; e != null; e = e.next) { + TreeNode p = + new TreeNode(e.hash, e.key, e.val, + null, null); + if ((p.prev = tl) == null) + hd = p; + else + tl.next = p; + tl = p; + } + setTabAt(tab, index, new TreeBin(hd)); + } + } + } + } + } + + /** + * Returns a list on non-TreeNodes replacing those in given list. + */ + static Node untreeify(Node b) { + Node hd = null, tl = null; + for (Node q = b; q != null; q = q.next) { + Node p = new Node(q.hash, q.key, q.val, null); + if (tl == null) + hd = p; + else + tl.next = p; + tl = p; + } + return hd; + } + + /* ---------------- TreeNodes -------------- */ + + /** + * Nodes for use in TreeBins + */ + static final class TreeNode extends Node { + TreeNode parent; // red-black tree links + TreeNode left; + TreeNode right; + TreeNode prev; // needed to unlink next upon deletion + boolean red; + + TreeNode(int hash, K key, V val, Node next, + TreeNode parent) { + super(hash, key, val, next); + this.parent = parent; + } + + Node find(int h, Object k) { + return findTreeNode(h, k, null); + } + + /** + * Returns the TreeNode (or null if not found) for the given key + * starting at given root. + */ + final TreeNode findTreeNode(int h, Object k, Class kc) { + if (k != null) { + TreeNode p = this; + do { + int ph, dir; K pk; TreeNode q; + TreeNode pl = p.left, pr = p.right; + if ((ph = p.hash) > h) + p = pl; + else if (ph < h) + p = pr; + else if ((pk = p.key) == k || (pk != null && k.equals(pk))) + return p; + else if (pl == null && pr == null) + break; + else if ((kc != null || + (kc = comparableClassFor(k)) != null) && + (dir = compareComparables(kc, k, pk)) != 0) + p = (dir < 0) ? pl : pr; + else if (pl == null) + p = pr; + else if (pr == null || + (q = pr.findTreeNode(h, k, kc)) == null) + p = pl; + else + return q; + } while (p != null); + } + return null; + } + } + + /* ---------------- TreeBins -------------- */ + + /** + * TreeNodes used at the heads of bins. TreeBins do not hold user + * keys or values, but instead point to list of TreeNodes and + * their root. They also maintain a parasitic read-write lock + * forcing writers (who hold bin lock) to wait for readers (who do + * not) to complete before tree restructuring operations. + */ + static final class TreeBin extends Node { + TreeNode root; + volatile TreeNode first; + volatile Thread waiter; + volatile int lockState; + // values for lockState + static final int WRITER = 1; // set while holding write lock + static final int WAITER = 2; // set when waiting for write lock + static final int READER = 4; // increment value for setting read lock + + /** + * Creates bin with initial set of nodes headed by b. + */ + TreeBin(TreeNode b) { + super(TREEBIN, null, null, null); + this.first = b; + TreeNode r = null; + for (TreeNode x = b, next; x != null; x = next) { + next = (TreeNode)x.next; + x.left = x.right = null; + if (r == null) { + x.parent = null; + x.red = false; + r = x; + } + else { + Object key = x.key; + int hash = x.hash; + Class kc = null; + for (TreeNode p = r;;) { + int dir, ph; + if ((ph = p.hash) > hash) + dir = -1; + else if (ph < hash) + dir = 1; + else if ((kc != null || + (kc = comparableClassFor(key)) != null)) + dir = compareComparables(kc, key, p.key); + else + dir = 0; + TreeNode xp = p; + if ((p = (dir <= 0) ? p.left : p.right) == null) { + x.parent = xp; + if (dir <= 0) + xp.left = x; + else + xp.right = x; + r = balanceInsertion(r, x); + break; + } + } + } + } + this.root = r; + } + + /** + * Acquires write lock for tree restructuring. + */ + private final void lockRoot() { + if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER)) + contendedLock(); // offload to separate method + } + + /** + * Releases write lock for tree restructuring. + */ + private final void unlockRoot() { + lockState = 0; + } + + /** + * Possibly blocks awaiting root lock. + */ + private final void contendedLock() { + boolean waiting = false; + for (int s;;) { + if (((s = lockState) & WRITER) == 0) { + if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) { + if (waiting) + waiter = null; + return; + } + } + else if ((s | WAITER) == 0) { + if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) { + waiting = true; + waiter = Thread.currentThread(); + } + } + else if (waiting) + LockSupport.park(this); + } + } + + /** + * Returns matching node or null if none. Tries to search + * using tree comparisons from root, but continues linear + * search when lock not available. + */ + final Node find(int h, Object k) { + if (k != null) { + for (Node e = first; e != null; e = e.next) { + int s; K ek; + if (((s = lockState) & (WAITER|WRITER)) != 0) { + if (e.hash == h && + ((ek = e.key) == k || (ek != null && k.equals(ek)))) + return e; + } + else if (U.compareAndSwapInt(this, LOCKSTATE, s, + s + READER)) { + TreeNode r, p; + try { + p = ((r = root) == null ? null : + r.findTreeNode(h, k, null)); + } finally { + Thread w; + int ls; + do {} while (!U.compareAndSwapInt + (this, LOCKSTATE, + ls = lockState, ls - READER)); + if (ls == (READER|WAITER) && (w = waiter) != null) + LockSupport.unpark(w); + } + return p; + } + } + } + return null; + } + + /** + * Finds or adds a node. + * @return null if added + */ + final TreeNode putTreeVal(int h, K k, V v) { + Class kc = null; + for (TreeNode p = root;;) { + int dir, ph; K pk; TreeNode q, pr; + if (p == null) { + first = root = new TreeNode(h, k, v, null, null); + break; + } + else if ((ph = p.hash) > h) + dir = -1; + else if (ph < h) + dir = 1; + else if ((pk = p.key) == k || (pk != null && k.equals(pk))) + return p; + else if ((kc == null && + (kc = comparableClassFor(k)) == null) || + (dir = compareComparables(kc, k, pk)) == 0) { + if (p.left == null) + dir = 1; + else if ((pr = p.right) == null || + (q = pr.findTreeNode(h, k, kc)) == null) + dir = -1; + else + return q; + } + TreeNode xp = p; + if ((p = (dir < 0) ? p.left : p.right) == null) { + TreeNode x, f = first; + first = x = new TreeNode(h, k, v, f, xp); + if (f != null) + f.prev = x; + if (dir < 0) + xp.left = x; + else + xp.right = x; + if (!xp.red) + x.red = true; + else { + lockRoot(); + try { + root = balanceInsertion(root, x); + } finally { + unlockRoot(); + } + } + break; + } + } + assert checkInvariants(root); + return null; + } + + /** + * Removes the given node, that must be present before this + * call. This is messier than typical red-black deletion code + * because we cannot swap the contents of an interior node + * with a leaf successor that is pinned by "next" pointers + * that are accessible independently of lock. So instead we + * swap the tree linkages. + * + * @return true if now too small, so should be untreeified + */ + final boolean removeTreeNode(TreeNode p) { + TreeNode next = (TreeNode)p.next; + TreeNode pred = p.prev; // unlink traversal pointers + TreeNode r, rl; + if (pred == null) + first = next; + else + pred.next = next; + if (next != null) + next.prev = pred; + if (first == null) { + root = null; + return true; + } + if ((r = root) == null || r.right == null || // too small + (rl = r.left) == null || rl.left == null) + return true; + lockRoot(); + try { + TreeNode replacement; + TreeNode pl = p.left; + TreeNode pr = p.right; + if (pl != null && pr != null) { + TreeNode s = pr, sl; + while ((sl = s.left) != null) // find successor + s = sl; + boolean c = s.red; s.red = p.red; p.red = c; // swap colors + TreeNode sr = s.right; + TreeNode pp = p.parent; + if (s == pr) { // p was s's direct parent + p.parent = s; + s.right = p; + } + else { + TreeNode sp = s.parent; + if ((p.parent = sp) != null) { + if (s == sp.left) + sp.left = p; + else + sp.right = p; + } + if ((s.right = pr) != null) + pr.parent = s; + } + p.left = null; + if ((p.right = sr) != null) + sr.parent = p; + if ((s.left = pl) != null) + pl.parent = s; + if ((s.parent = pp) == null) + r = s; + else if (p == pp.left) + pp.left = s; + else + pp.right = s; + if (sr != null) + replacement = sr; + else + replacement = p; + } + else if (pl != null) + replacement = pl; + else if (pr != null) + replacement = pr; + else + replacement = p; + if (replacement != p) { + TreeNode pp = replacement.parent = p.parent; + if (pp == null) + r = replacement; + else if (p == pp.left) + pp.left = replacement; + else + pp.right = replacement; + p.left = p.right = p.parent = null; + } + + root = (p.red) ? r : balanceDeletion(r, replacement); + + if (p == replacement) { // detach pointers + TreeNode pp; + if ((pp = p.parent) != null) { + if (p == pp.left) + pp.left = null; + else if (p == pp.right) + pp.right = null; + p.parent = null; + } + } + } finally { + unlockRoot(); + } + assert checkInvariants(root); + return false; + } + + /* ------------------------------------------------------------ */ + // Red-black tree methods, all adapted from CLR + + static TreeNode rotateLeft(TreeNode root, + TreeNode p) { + TreeNode r, pp, rl; + if (p != null && (r = p.right) != null) { + if ((rl = p.right = r.left) != null) + rl.parent = p; + if ((pp = r.parent = p.parent) == null) + (root = r).red = false; + else if (pp.left == p) + pp.left = r; + else + pp.right = r; + r.left = p; + p.parent = r; + } + return root; + } + + static TreeNode rotateRight(TreeNode root, + TreeNode p) { + TreeNode l, pp, lr; + if (p != null && (l = p.left) != null) { + if ((lr = p.left = l.right) != null) + lr.parent = p; + if ((pp = l.parent = p.parent) == null) + (root = l).red = false; + else if (pp.right == p) + pp.right = l; + else + pp.left = l; + l.right = p; + p.parent = l; + } + return root; + } + + static TreeNode balanceInsertion(TreeNode root, + TreeNode x) { + x.red = true; + for (TreeNode xp, xpp, xppl, xppr;;) { + if ((xp = x.parent) == null) { + x.red = false; + return x; + } + else if (!xp.red || (xpp = xp.parent) == null) + return root; + if (xp == (xppl = xpp.left)) { + if ((xppr = xpp.right) != null && xppr.red) { + xppr.red = false; + xp.red = false; + xpp.red = true; + x = xpp; + } + else { + if (x == xp.right) { + root = rotateLeft(root, x = xp); + xpp = (xp = x.parent) == null ? null : xp.parent; + } + if (xp != null) { + xp.red = false; + if (xpp != null) { + xpp.red = true; + root = rotateRight(root, xpp); + } + } + } + } + else { + if (xppl != null && xppl.red) { + xppl.red = false; + xp.red = false; + xpp.red = true; + x = xpp; + } + else { + if (x == xp.left) { + root = rotateRight(root, x = xp); + xpp = (xp = x.parent) == null ? null : xp.parent; + } + if (xp != null) { + xp.red = false; + if (xpp != null) { + xpp.red = true; + root = rotateLeft(root, xpp); } } } } } - if (!init) { // Can only happen if unsafely published. - while (p != null) { - internalPut((K)p.key, p.val, false); - p = p.next; + } + + static TreeNode balanceDeletion(TreeNode root, + TreeNode x) { + for (TreeNode xp, xpl, xpr;;) { + if (x == null || x == root) + return root; + else if ((xp = x.parent) == null) { + x.red = false; + return x; } + else if (x.red) { + x.red = false; + return root; + } + else if ((xpl = xp.left) == x) { + if ((xpr = xp.right) != null && xpr.red) { + xpr.red = false; + xp.red = true; + root = rotateLeft(root, xp); + xpr = (xp = x.parent) == null ? null : xp.right; + } + if (xpr == null) + x = xp; + else { + TreeNode sl = xpr.left, sr = xpr.right; + if ((sr == null || !sr.red) && + (sl == null || !sl.red)) { + xpr.red = true; + x = xp; + } + else { + if (sr == null || !sr.red) { + if (sl != null) + sl.red = false; + xpr.red = true; + root = rotateRight(root, xpr); + xpr = (xp = x.parent) == null ? + null : xp.right; + } + if (xpr != null) { + xpr.red = (xp == null) ? false : xp.red; + if ((sr = xpr.right) != null) + sr.red = false; + } + if (xp != null) { + xp.red = false; + root = rotateLeft(root, xp); + } + x = root; + } + } + } + else { // symmetric + if (xpl != null && xpl.red) { + xpl.red = false; + xp.red = true; + root = rotateRight(root, xp); + xpl = (xp = x.parent) == null ? null : xp.left; + } + if (xpl == null) + x = xp; + else { + TreeNode sl = xpl.left, sr = xpl.right; + if ((sl == null || !sl.red) && + (sr == null || !sr.red)) { + xpl.red = true; + x = xp; + } + else { + if (sl == null || !sl.red) { + if (sr != null) + sr.red = false; + xpl.red = true; + root = rotateLeft(root, xpl); + xpl = (xp = x.parent) == null ? + null : xp.left; + } + if (xpl != null) { + xpl.red = (xp == null) ? false : xp.red; + if ((sl = xpl.left) != null) + sl.red = false; + } + if (xp != null) { + xp.red = false; + root = rotateRight(root, xp); + } + x = root; + } + } + } + } + } + + /** + * Recursive invariant check + */ + static boolean checkInvariants(TreeNode t) { + TreeNode tp = t.parent, tl = t.left, tr = t.right, + tb = t.prev, tn = (TreeNode)t.next; + if (tb != null && tb.next != t) + return false; + if (tn != null && tn.prev != t) + return false; + if (tp != null && t != tp.left && t != tp.right) + return false; + if (tl != null && (tl.parent != t || tl.hash > t.hash)) + return false; + if (tr != null && (tr.parent != t || tr.hash < t.hash)) + return false; + if (t.red && tl != null && tl.red && tr != null && tr.red) + return false; + if (tl != null && !checkInvariants(tl)) + return false; + if (tr != null && !checkInvariants(tr)) + return false; + return true; + } + + private static final sun.misc.Unsafe U; + private static final long LOCKSTATE; + static { + try { + U = getUnsafe(); + Class k = TreeBin.class; + LOCKSTATE = U.objectFieldOffset + (k.getDeclaredField("lockState")); + } catch (Exception e) { + throw new Error(e); } } } - // ------------------------------------------------------- - - // Sams - /** Interface describing a void action of one argument */ - public interface Action { void apply(A a); } - /** Interface describing a void action of two arguments */ - public interface BiAction { void apply(A a, B b); } - /** Interface describing a function of one argument */ - public interface Fun { T apply(A a); } - /** Interface describing a function of two arguments */ - public interface BiFun { T apply(A a, B b); } - /** Interface describing a function of no arguments */ - public interface Generator { T apply(); } - /** Interface describing a function mapping its argument to a double */ - public interface ObjectToDouble { double apply(A a); } - /** Interface describing a function mapping its argument to a long */ - public interface ObjectToLong { long apply(A a); } - /** Interface describing a function mapping its argument to an int */ - public interface ObjectToInt {int apply(A a); } - /** Interface describing a function mapping two arguments to a double */ - public interface ObjectByObjectToDouble { double apply(A a, B b); } - /** Interface describing a function mapping two arguments to a long */ - public interface ObjectByObjectToLong { long apply(A a, B b); } - /** Interface describing a function mapping two arguments to an int */ - public interface ObjectByObjectToInt {int apply(A a, B b); } - /** Interface describing a function mapping a double to a double */ - public interface DoubleToDouble { double apply(double a); } - /** Interface describing a function mapping a long to a long */ - public interface LongToLong { long apply(long a); } - /** Interface describing a function mapping an int to an int */ - public interface IntToInt { int apply(int a); } - /** Interface describing a function mapping two doubles to a double */ - public interface DoubleByDoubleToDouble { double apply(double a, double b); } - /** Interface describing a function mapping two longs to a long */ - public interface LongByLongToLong { long apply(long a, long b); } - /** Interface describing a function mapping two ints to an int */ - public interface IntByIntToInt { int apply(int a, int b); } - - - // ------------------------------------------------------- - - // Sequential bulk operations + /* ----------------Table Traversal -------------- */ /** - * Performs the given action for each (key, value). + * Encapsulates traversal for methods such as containsValue; also + * serves as a base class for other iterators and spliterators. * - * @param action the action + * Method advance visits once each still-valid node that was + * reachable upon iterator construction. It might miss some that + * were added to a bin after the bin was visited, which is OK wrt + * consistency guarantees. Maintaining this property in the face + * of possible ongoing resizes requires a fair amount of + * bookkeeping state that is difficult to optimize away amidst + * volatile accesses. Even so, traversal maintains reasonable + * throughput. + * + * Normally, iteration proceeds bin-by-bin traversing lists. + * However, if the table has been resized, then all future steps + * must traverse both the bin at the current index as well as at + * (index + baseSize); and so on for further resizings. To + * paranoically cope with potential sharing by users of iterators + * across threads, iteration terminates if a bounds checks fails + * for a table read. */ - @SuppressWarnings("unchecked") public void forEachSequentially - (BiAction action) { - if (action == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; - while ((v = it.advance()) != null) - action.apply((K)it.nextKey, v); - } + static class Traverser { + Node[] tab; // current table; updated if resized + Node next; // the next entry to use + int index; // index of bin to use next + int baseIndex; // current index of initial table + int baseLimit; // index bound for initial table + final int baseSize; // initial table size - /** - * Performs the given action for each non-null transformation - * of each (key, value). - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - */ - @SuppressWarnings("unchecked") public void forEachSequentially - (BiFun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; U u; - while ((v = it.advance()) != null) { - if ((u = transformer.apply((K)it.nextKey, v)) != null) - action.apply(u); + Traverser(Node[] tab, int size, int index, int limit) { + this.tab = tab; + this.baseSize = size; + this.baseIndex = this.index = index; + this.baseLimit = limit; + this.next = null; + } + + /** + * Advances if possible, returning next valid node, or null if none. + */ + final Node advance() { + Node e; + if ((e = next) != null) + e = e.next; + for (;;) { + Node[] t; int i, n; K ek; // must use locals in checks + if (e != null) + return next = e; + if (baseIndex >= baseLimit || (t = tab) == null || + (n = t.length) <= (i = index) || i < 0) + return next = null; + if ((e = tabAt(t, index)) != null && e.hash < 0) { + if (e instanceof ForwardingNode) { + tab = ((ForwardingNode)e).nextTable; + e = null; + continue; + } + else if (e instanceof TreeBin) + e = ((TreeBin)e).first; + else + e = null; + } + if ((index += baseSize) >= n) + index = ++baseIndex; // visit upper slots if present + } } } /** - * Returns a non-null result from applying the given search - * function on each (key, value), or null if none. - * - * @param searchFunction a function returning a non-null - * result on success, else null - * @return a non-null result from applying the given search - * function on each (key, value), or null if none + * Base of key, value, and entry Iterators. Adds fields to + * Traverser to support iterator.remove. */ - @SuppressWarnings("unchecked") public U searchSequentially - (BiFun searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; U u; - while ((v = it.advance()) != null) { - if ((u = searchFunction.apply((K)it.nextKey, v)) != null) - return u; + static class BaseIterator extends Traverser { + final ConcurrentHashMapV8 map; + Node lastReturned; + BaseIterator(Node[] tab, int size, int index, int limit, + ConcurrentHashMapV8 map) { + super(tab, size, index, limit); + this.map = map; + advance(); } - return null; - } - /** - * Returns the result of accumulating the given transformation - * of all (key, value) pairs using the given reducer to - * combine values, or null if none. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all (key, value) pairs - */ - @SuppressWarnings("unchecked") public U reduceSequentially - (BiFun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - U r = null, u; V v; - while ((v = it.advance()) != null) { - if ((u = transformer.apply((K)it.nextKey, v)) != null) - r = (r == null) ? u : reducer.apply(r, u); + public final boolean hasNext() { return next != null; } + public final boolean hasMoreElements() { return next != null; } + + public final void remove() { + Node p; + if ((p = lastReturned) == null) + throw new IllegalStateException(); + lastReturned = null; + map.replaceNode(p.key, null, null); } - return r; } - /** - * Returns the result of accumulating the given transformation - * of all (key, value) pairs using the given reducer to - * combine values, and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all (key, value) pairs - */ - @SuppressWarnings("unchecked") public double reduceToDoubleSequentially - (ObjectByObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - double r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply((K)it.nextKey, v)); - return r; - } - - /** - * Returns the result of accumulating the given transformation - * of all (key, value) pairs using the given reducer to - * combine values, and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all (key, value) pairs - */ - @SuppressWarnings("unchecked") public long reduceToLongSequentially - (ObjectByObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - long r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply((K)it.nextKey, v)); - return r; - } - - /** - * Returns the result of accumulating the given transformation - * of all (key, value) pairs using the given reducer to - * combine values, and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all (key, value) pairs - */ - @SuppressWarnings("unchecked") public int reduceToIntSequentially - (ObjectByObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - int r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply((K)it.nextKey, v)); - return r; - } - - /** - * Performs the given action for each key. - * - * @param action the action - */ - @SuppressWarnings("unchecked") public void forEachKeySequentially - (Action action) { - if (action == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - while (it.advance() != null) - action.apply((K)it.nextKey); - } - - /** - * Performs the given action for each non-null transformation - * of each key. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - */ - @SuppressWarnings("unchecked") public void forEachKeySequentially - (Fun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - U u; - while (it.advance() != null) { - if ((u = transformer.apply((K)it.nextKey)) != null) - action.apply(u); + static final class KeyIterator extends BaseIterator + implements Iterator, Enumeration { + KeyIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); } - ForkJoinTasks.forEachKey - (this, transformer, action).invoke(); - } - /** - * Returns a non-null result from applying the given search - * function on each key, or null if none. - * - * @param searchFunction a function returning a non-null - * result on success, else null - * @return a non-null result from applying the given search - * function on each key, or null if none - */ - @SuppressWarnings("unchecked") public U searchKeysSequentially - (Fun searchFunction) { - Traverser it = new Traverser(this); - U u; - while (it.advance() != null) { - if ((u = searchFunction.apply((K)it.nextKey)) != null) - return u; + public final K next() { + Node p; + if ((p = next) == null) + throw new NoSuchElementException(); + K k = p.key; + lastReturned = p; + advance(); + return k; } - return null; + + public final K nextElement() { return next(); } } - /** - * Returns the result of accumulating all keys using the given - * reducer to combine values, or null if none. - * - * @param reducer a commutative associative combining function - * @return the result of accumulating all keys using the given - * reducer to combine values, or null if none - */ - @SuppressWarnings("unchecked") public K reduceKeysSequentially - (BiFun reducer) { - if (reducer == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - K r = null; - while (it.advance() != null) { - K u = (K)it.nextKey; - r = (r == null) ? u : reducer.apply(r, u); + static final class ValueIterator extends BaseIterator + implements Iterator, Enumeration { + ValueIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); } - return r; - } - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, or - * null if none. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - @SuppressWarnings("unchecked") public U reduceKeysSequentially - (Fun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - U r = null, u; - while (it.advance() != null) { - if ((u = transformer.apply((K)it.nextKey)) != null) - r = (r == null) ? u : reducer.apply(r, u); + public final V next() { + Node p; + if ((p = next) == null) + throw new NoSuchElementException(); + V v = p.val; + lastReturned = p; + advance(); + return v; } - return r; + + public final V nextElement() { return next(); } } - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, and - * the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - @SuppressWarnings("unchecked") public double reduceKeysToDoubleSequentially - (ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - double r = basis; - while (it.advance() != null) - r = reducer.apply(r, transformer.apply((K)it.nextKey)); - return r; - } + static final class EntryIterator extends BaseIterator + implements Iterator> { + EntryIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); + } - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, and - * the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - @SuppressWarnings("unchecked") public long reduceKeysToLongSequentially - (ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - long r = basis; - while (it.advance() != null) - r = reducer.apply(r, transformer.apply((K)it.nextKey)); - return r; - } - - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, and - * the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - @SuppressWarnings("unchecked") public int reduceKeysToIntSequentially - (ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - int r = basis; - while (it.advance() != null) - r = reducer.apply(r, transformer.apply((K)it.nextKey)); - return r; - } - - /** - * Performs the given action for each value. - * - * @param action the action - */ - public void forEachValueSequentially(Action action) { - if (action == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; - while ((v = it.advance()) != null) - action.apply(v); - } - - /** - * Performs the given action for each non-null transformation - * of each value. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - */ - public void forEachValueSequentially - (Fun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; U u; - while ((v = it.advance()) != null) { - if ((u = transformer.apply(v)) != null) - action.apply(u); + public final Map.Entry next() { + Node p; + if ((p = next) == null) + throw new NoSuchElementException(); + K k = p.key; + V v = p.val; + lastReturned = p; + advance(); + return new MapEntry(k, v, map); } } /** - * Returns a non-null result from applying the given search - * function on each value, or null if none. - * - * @param searchFunction a function returning a non-null - * result on success, else null - * @return a non-null result from applying the given search - * function on each value, or null if none + * Exported Entry for EntryIterator */ - public U searchValuesSequentially - (Fun searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; U u; - while ((v = it.advance()) != null) { - if ((u = searchFunction.apply(v)) != null) - return u; + static final class MapEntry implements Map.Entry { + final K key; // non-null + V val; // non-null + final ConcurrentHashMapV8 map; + MapEntry(K key, V val, ConcurrentHashMapV8 map) { + this.key = key; + this.val = val; + this.map = map; } - return null; - } + public K getKey() { return key; } + public V getValue() { return val; } + public int hashCode() { return key.hashCode() ^ val.hashCode(); } + public String toString() { return key + "=" + val; } - /** - * Returns the result of accumulating all values using the - * given reducer to combine values, or null if none. - * - * @param reducer a commutative associative combining function - * @return the result of accumulating all values - */ - public V reduceValuesSequentially - (BiFun reducer) { - if (reducer == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V r = null; V v; - while ((v = it.advance()) != null) - r = (r == null) ? v : reducer.apply(r, v); - return r; - } - - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, or - * null if none. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public U reduceValuesSequentially - (Fun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - U r = null, u; V v; - while ((v = it.advance()) != null) { - if ((u = transformer.apply(v)) != null) - r = (r == null) ? u : reducer.apply(r, u); + public boolean equals(Object o) { + Object k, v; Map.Entry e; + return ((o instanceof Map.Entry) && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + (k == key || k.equals(key)) && + (v == val || v.equals(val))); } - return r; - } - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public double reduceValuesToDoubleSequentially - (ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - double r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply(v)); - return r; - } - - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public long reduceValuesToLongSequentially - (ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - long r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply(v)); - return r; - } - - /** - * Returns the result of accumulating the given transformation - * of all values using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all values - */ - public int reduceValuesToIntSequentially - (ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - int r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply(v)); - return r; - } - - /** - * Performs the given action for each entry. - * - * @param action the action - */ - @SuppressWarnings("unchecked") public void forEachEntrySequentially - (Action> action) { - if (action == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; - while ((v = it.advance()) != null) - action.apply(entryFor((K)it.nextKey, v)); - } - - /** - * Performs the given action for each non-null transformation - * of each entry. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - */ - @SuppressWarnings("unchecked") public void forEachEntrySequentially - (Fun, ? extends U> transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; U u; - while ((v = it.advance()) != null) { - if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null) - action.apply(u); + /** + * Sets our entry's value and writes through to the map. The + * value to return is somewhat arbitrary here. Since we do not + * necessarily track asynchronous changes, the most recent + * "previous" value could be different from what we return (or + * could even have been removed, in which case the put will + * re-establish). We do not and cannot guarantee more. + */ + public V setValue(V value) { + if (value == null) throw new NullPointerException(); + V v = val; + val = value; + map.put(key, value); + return v; } } - /** - * Returns a non-null result from applying the given search - * function on each entry, or null if none. - * - * @param searchFunction a function returning a non-null - * result on success, else null - * @return a non-null result from applying the given search - * function on each entry, or null if none - */ - @SuppressWarnings("unchecked") public U searchEntriesSequentially - (Fun, ? extends U> searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - V v; U u; - while ((v = it.advance()) != null) { - if ((u = searchFunction.apply(entryFor((K)it.nextKey, v))) != null) - return u; + static final class KeySpliterator extends Traverser + implements ConcurrentHashMapSpliterator { + long est; // size estimate + KeySpliterator(Node[] tab, int size, int index, int limit, + long est) { + super(tab, size, index, limit); + this.est = est; } - return null; - } - /** - * Returns the result of accumulating all entries using the - * given reducer to combine values, or null if none. - * - * @param reducer a commutative associative combining function - * @return the result of accumulating all entries - */ - @SuppressWarnings("unchecked") public Map.Entry reduceEntriesSequentially - (BiFun, Map.Entry, ? extends Map.Entry> reducer) { - if (reducer == null) throw new NullPointerException(); - Traverser it = new Traverser(this); - Map.Entry r = null; V v; - while ((v = it.advance()) != null) { - Map.Entry u = entryFor((K)it.nextKey, v); - r = (r == null) ? u : reducer.apply(r, u); + public ConcurrentHashMapSpliterator trySplit() { + int i, f, h; + return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null : + new KeySpliterator(tab, baseSize, baseLimit = h, + f, est >>>= 1); } - return r; - } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * or null if none. - * - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - @SuppressWarnings("unchecked") public U reduceEntriesSequentially - (Fun, ? extends U> transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - U r = null, u; V v; - while ((v = it.advance()) != null) { - if ((u = transformer.apply(entryFor((K)it.nextKey, v))) != null) - r = (r == null) ? u : reducer.apply(r, u); + public void forEachRemaining(Action action) { + if (action == null) throw new NullPointerException(); + for (Node p; (p = advance()) != null;) + action.apply(p.key); } - return r; + + public boolean tryAdvance(Action action) { + if (action == null) throw new NullPointerException(); + Node p; + if ((p = advance()) == null) + return false; + action.apply(p.key); + return true; + } + + public long estimateSize() { return est; } + } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - @SuppressWarnings("unchecked") public double reduceEntriesToDoubleSequentially - (ObjectToDouble> transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - double r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v))); - return r; + static final class ValueSpliterator extends Traverser + implements ConcurrentHashMapSpliterator { + long est; // size estimate + ValueSpliterator(Node[] tab, int size, int index, int limit, + long est) { + super(tab, size, index, limit); + this.est = est; + } + + public ConcurrentHashMapSpliterator trySplit() { + int i, f, h; + return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null : + new ValueSpliterator(tab, baseSize, baseLimit = h, + f, est >>>= 1); + } + + public void forEachRemaining(Action action) { + if (action == null) throw new NullPointerException(); + for (Node p; (p = advance()) != null;) + action.apply(p.val); + } + + public boolean tryAdvance(Action action) { + if (action == null) throw new NullPointerException(); + Node p; + if ((p = advance()) == null) + return false; + action.apply(p.val); + return true; + } + + public long estimateSize() { return est; } + } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - @SuppressWarnings("unchecked") public long reduceEntriesToLongSequentially - (ObjectToLong> transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - long r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v))); - return r; - } + static final class EntrySpliterator extends Traverser + implements ConcurrentHashMapSpliterator> { + final ConcurrentHashMapV8 map; // To export MapEntry + long est; // size estimate + EntrySpliterator(Node[] tab, int size, int index, int limit, + long est, ConcurrentHashMapV8 map) { + super(tab, size, index, limit); + this.map = map; + this.est = est; + } + + public ConcurrentHashMapSpliterator> trySplit() { + int i, f, h; + return (h = ((i = baseIndex) + (f = baseLimit)) >>> 1) <= i ? null : + new EntrySpliterator(tab, baseSize, baseLimit = h, + f, est >>>= 1, map); + } + + public void forEachRemaining(Action> action) { + if (action == null) throw new NullPointerException(); + for (Node p; (p = advance()) != null; ) + action.apply(new MapEntry(p.key, p.val, map)); + } + + public boolean tryAdvance(Action> action) { + if (action == null) throw new NullPointerException(); + Node p; + if ((p = advance()) == null) + return false; + action.apply(new MapEntry(p.key, p.val, map)); + return true; + } + + public long estimateSize() { return est; } - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - @SuppressWarnings("unchecked") public int reduceEntriesToIntSequentially - (ObjectToInt> transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - Traverser it = new Traverser(this); - int r = basis; V v; - while ((v = it.advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)it.nextKey, v))); - return r; } // Parallel bulk operations + /** + * Computes initial batch value for bulk tasks. The returned value + * is approximately exp2 of the number of times (minus one) to + * split task by two before executing leaf action. This value is + * faster to compute and more convenient to use as a guide to + * splitting than is the depth, since it is used while dividing by + * two anyway. + */ + final int batchFor(long b) { + long n; + if (b == Long.MAX_VALUE || (n = sumCount()) <= 1L || n < b) + return 0; + int sp = ForkJoinPool.getCommonPoolParallelism() << 2; // slack of 4 + return (b <= 0L || (n /= b) >= sp) ? sp : (int)n; + } + /** * Performs the given action for each (key, value). * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param action the action + * @since 1.8 */ - public void forEachInParallel(BiAction action) { - ForkJoinTasks.forEach - (this, action).invoke(); + public void forEach(long parallelismThreshold, + BiAction action) { + if (action == null) throw new NullPointerException(); + new ForEachMappingTask + (null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); } /** * Performs the given action for each non-null transformation * of each (key, value). * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action + * @since 1.8 */ - public void forEachInParallel - (BiFun transformer, - Action action) { - ForkJoinTasks.forEach - (this, transformer, action).invoke(); + public void forEach(long parallelismThreshold, + BiFun transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedMappingTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); } /** @@ -4074,15 +3460,20 @@ public class ConcurrentHashMapV8 * results of any other parallel invocations of the search * function are ignored. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each (key, value), or null if none + * @since 1.8 */ - public U searchInParallel - (BiFun searchFunction) { - return ForkJoinTasks.search - (this, searchFunction).invoke(); + public U search(long parallelismThreshold, + BiFun searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchMappingsTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); } /** @@ -4090,18 +3481,24 @@ public class ConcurrentHashMapV8 * of all (key, value) pairs using the given reducer to * combine values, or null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs + * @since 1.8 */ - public U reduceInParallel - (BiFun transformer, - BiFun reducer) { - return ForkJoinTasks.reduce - (this, transformer, reducer).invoke(); + public U reduce(long parallelismThreshold, + BiFun transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); } /** @@ -4109,19 +3506,25 @@ public class ConcurrentHashMapV8 * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs + * @since 1.8 */ - public double reduceToDoubleInParallel - (ObjectByObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return ForkJoinTasks.reduceToDouble - (this, transformer, basis, reducer).invoke(); + public double reduceToDouble(long parallelismThreshold, + ObjectByObjectToDouble transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** @@ -4129,19 +3532,25 @@ public class ConcurrentHashMapV8 * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs + * @since 1.8 */ - public long reduceToLongInParallel - (ObjectByObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - return ForkJoinTasks.reduceToLong - (this, transformer, basis, reducer).invoke(); + public long reduceToLong(long parallelismThreshold, + ObjectByObjectToLong transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** @@ -4149,45 +3558,63 @@ public class ConcurrentHashMapV8 * of all (key, value) pairs using the given reducer to * combine values, and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all (key, value) pairs + * @since 1.8 */ - public int reduceToIntInParallel - (ObjectByObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - return ForkJoinTasks.reduceToInt - (this, transformer, basis, reducer).invoke(); + public int reduceToInt(long parallelismThreshold, + ObjectByObjectToInt transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceMappingsToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** * Performs the given action for each key. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param action the action + * @since 1.8 */ - public void forEachKeyInParallel(Action action) { - ForkJoinTasks.forEachKey - (this, action).invoke(); + public void forEachKey(long parallelismThreshold, + Action action) { + if (action == null) throw new NullPointerException(); + new ForEachKeyTask + (null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); } /** * Performs the given action for each non-null transformation * of each key. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action + * @since 1.8 */ - public void forEachKeyInParallel - (Fun transformer, - Action action) { - ForkJoinTasks.forEachKey - (this, transformer, action).invoke(); + public void forEachKey(long parallelismThreshold, + Fun transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedKeyTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); } /** @@ -4197,29 +3624,39 @@ public class ConcurrentHashMapV8 * any other parallel invocations of the search function are * ignored. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each key, or null if none + * @since 1.8 */ - public U searchKeysInParallel - (Fun searchFunction) { - return ForkJoinTasks.searchKeys - (this, searchFunction).invoke(); + public U searchKeys(long parallelismThreshold, + Fun searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchKeysTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); } /** * Returns the result of accumulating all keys using the given * reducer to combine values, or null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param reducer a commutative associative combining function * @return the result of accumulating all keys using the given * reducer to combine values, or null if none + * @since 1.8 */ - public K reduceKeysInParallel - (BiFun reducer) { - return ForkJoinTasks.reduceKeys - (this, reducer).invoke(); + public K reduceKeys(long parallelismThreshold, + BiFun reducer) { + if (reducer == null) throw new NullPointerException(); + return new ReduceKeysTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, reducer).invoke(); } /** @@ -4227,38 +3664,24 @@ public class ConcurrentHashMapV8 * of all keys using the given reducer to combine values, or * null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys + * @since 1.8 */ - public U reduceKeysInParallel - (Fun transformer, + public U reduceKeys(long parallelismThreshold, + Fun transformer, BiFun reducer) { - return ForkJoinTasks.reduceKeys - (this, transformer, reducer).invoke(); - } - - /** - * Returns the result of accumulating the given transformation - * of all keys using the given reducer to combine values, and - * the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all keys - */ - public double reduceKeysToDoubleInParallel - (ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return ForkJoinTasks.reduceKeysToDouble - (this, transformer, basis, reducer).invoke(); + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); } /** @@ -4266,19 +3689,25 @@ public class ConcurrentHashMapV8 * of all keys using the given reducer to combine values, and * the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys + * @since 1.8 */ - public long reduceKeysToLongInParallel - (ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - return ForkJoinTasks.reduceKeysToLong - (this, transformer, basis, reducer).invoke(); + public double reduceKeysToDouble(long parallelismThreshold, + ObjectToDouble transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** @@ -4286,44 +3715,90 @@ public class ConcurrentHashMapV8 * of all keys using the given reducer to combine values, and * the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all keys + * @since 1.8 */ - public int reduceKeysToIntInParallel - (ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - return ForkJoinTasks.reduceKeysToInt - (this, transformer, basis, reducer).invoke(); + public long reduceKeysToLong(long parallelismThreshold, + ObjectToLong transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all keys using the given reducer to combine values, and + * the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all keys + * @since 1.8 + */ + public int reduceKeysToInt(long parallelismThreshold, + ObjectToInt transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceKeysToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** * Performs the given action for each value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param action the action + * @since 1.8 */ - public void forEachValueInParallel(Action action) { - ForkJoinTasks.forEachValue - (this, action).invoke(); + public void forEachValue(long parallelismThreshold, + Action action) { + if (action == null) + throw new NullPointerException(); + new ForEachValueTask + (null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); } /** * Performs the given action for each non-null transformation * of each value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) + * @param action the action + * @since 1.8 */ - public void forEachValueInParallel - (Fun transformer, - Action action) { - ForkJoinTasks.forEachValue - (this, transformer, action).invoke(); + public void forEachValue(long parallelismThreshold, + Fun transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedValueTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); } /** @@ -4333,28 +3808,38 @@ public class ConcurrentHashMapV8 * any other parallel invocations of the search function are * ignored. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each value, or null if none + * @since 1.8 */ - public U searchValuesInParallel - (Fun searchFunction) { - return ForkJoinTasks.searchValues - (this, searchFunction).invoke(); + public U searchValues(long parallelismThreshold, + Fun searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchValuesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); } /** * Returns the result of accumulating all values using the * given reducer to combine values, or null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param reducer a commutative associative combining function - * @return the result of accumulating all values + * @return the result of accumulating all values + * @since 1.8 */ - public V reduceValuesInParallel - (BiFun reducer) { - return ForkJoinTasks.reduceValues - (this, reducer).invoke(); + public V reduceValues(long parallelismThreshold, + BiFun reducer) { + if (reducer == null) throw new NullPointerException(); + return new ReduceValuesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, reducer).invoke(); } /** @@ -4362,18 +3847,24 @@ public class ConcurrentHashMapV8 * of all values using the given reducer to combine values, or * null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values + * @since 1.8 */ - public U reduceValuesInParallel - (Fun transformer, - BiFun reducer) { - return ForkJoinTasks.reduceValues - (this, transformer, reducer).invoke(); + public U reduceValues(long parallelismThreshold, + Fun transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); } /** @@ -4381,19 +3872,25 @@ public class ConcurrentHashMapV8 * of all values using the given reducer to combine values, * and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values + * @since 1.8 */ - public double reduceValuesToDoubleInParallel - (ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return ForkJoinTasks.reduceValuesToDouble - (this, transformer, basis, reducer).invoke(); + public double reduceValuesToDouble(long parallelismThreshold, + ObjectToDouble transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** @@ -4401,19 +3898,25 @@ public class ConcurrentHashMapV8 * of all values using the given reducer to combine values, * and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values + * @since 1.8 */ - public long reduceValuesToLongInParallel - (ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - return ForkJoinTasks.reduceValuesToLong - (this, transformer, basis, reducer).invoke(); + public long reduceValuesToLong(long parallelismThreshold, + ObjectToLong transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** @@ -4421,45 +3924,62 @@ public class ConcurrentHashMapV8 * of all values using the given reducer to combine values, * and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all values + * @since 1.8 */ - public int reduceValuesToIntInParallel - (ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - return ForkJoinTasks.reduceValuesToInt - (this, transformer, basis, reducer).invoke(); + public int reduceValuesToInt(long parallelismThreshold, + ObjectToInt transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceValuesToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** * Performs the given action for each entry. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param action the action + * @since 1.8 */ - public void forEachEntryInParallel(Action> action) { - ForkJoinTasks.forEachEntry - (this, action).invoke(); + public void forEachEntry(long parallelismThreshold, + Action> action) { + if (action == null) throw new NullPointerException(); + new ForEachEntryTask(null, batchFor(parallelismThreshold), 0, 0, table, + action).invoke(); } /** * Performs the given action for each non-null transformation * of each entry. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case the action is not applied) * @param action the action + * @since 1.8 */ - public void forEachEntryInParallel - (Fun, ? extends U> transformer, - Action action) { - ForkJoinTasks.forEachEntry - (this, transformer, action).invoke(); + public void forEachEntry(long parallelismThreshold, + Fun, ? extends U> transformer, + Action action) { + if (transformer == null || action == null) + throw new NullPointerException(); + new ForEachTransformedEntryTask + (null, batchFor(parallelismThreshold), 0, 0, table, + transformer, action).invoke(); } /** @@ -4469,28 +3989,38 @@ public class ConcurrentHashMapV8 * any other parallel invocations of the search function are * ignored. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param searchFunction a function returning a non-null * result on success, else null * @return a non-null result from applying the given search * function on each entry, or null if none + * @since 1.8 */ - public U searchEntriesInParallel - (Fun, ? extends U> searchFunction) { - return ForkJoinTasks.searchEntries - (this, searchFunction).invoke(); + public U searchEntries(long parallelismThreshold, + Fun, ? extends U> searchFunction) { + if (searchFunction == null) throw new NullPointerException(); + return new SearchEntriesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + searchFunction, new AtomicReference()).invoke(); } /** * Returns the result of accumulating all entries using the * given reducer to combine values, or null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param reducer a commutative associative combining function * @return the result of accumulating all entries + * @since 1.8 */ - public Map.Entry reduceEntriesInParallel - (BiFun, Map.Entry, ? extends Map.Entry> reducer) { - return ForkJoinTasks.reduceEntries - (this, reducer).invoke(); + public Map.Entry reduceEntries(long parallelismThreshold, + BiFun, Map.Entry, ? extends Map.Entry> reducer) { + if (reducer == null) throw new NullPointerException(); + return new ReduceEntriesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, reducer).invoke(); } /** @@ -4498,18 +4028,24 @@ public class ConcurrentHashMapV8 * of all entries using the given reducer to combine values, * or null if none. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element, or null if there is no transformation (in * which case it is not combined) * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries + * @since 1.8 */ - public U reduceEntriesInParallel - (Fun, ? extends U> transformer, - BiFun reducer) { - return ForkJoinTasks.reduceEntries - (this, transformer, reducer).invoke(); + public U reduceEntries(long parallelismThreshold, + Fun, ? extends U> transformer, + BiFun reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, reducer).invoke(); } /** @@ -4517,39 +4053,25 @@ public class ConcurrentHashMapV8 * of all entries using the given reducer to combine values, * and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries + * @since 1.8 */ - public double reduceEntriesToDoubleInParallel - (ObjectToDouble> transformer, - double basis, - DoubleByDoubleToDouble reducer) { - return ForkJoinTasks.reduceEntriesToDouble - (this, transformer, basis, reducer).invoke(); - } - - /** - * Returns the result of accumulating the given transformation - * of all entries using the given reducer to combine values, - * and the given basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the result of accumulating the given transformation - * of all entries - */ - public long reduceEntriesToLongInParallel - (ObjectToLong> transformer, - long basis, - LongByLongToLong reducer) { - return ForkJoinTasks.reduceEntriesToLong - (this, transformer, basis, reducer).invoke(); + public double reduceEntriesToDouble(long parallelismThreshold, + ObjectToDouble> transformer, + double basis, + DoubleByDoubleToDouble reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesToDoubleTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } /** @@ -4557,19 +4079,51 @@ public class ConcurrentHashMapV8 * of all entries using the given reducer to combine values, * and the given basis as an identity value. * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel * @param transformer a function returning the transformation * for an element * @param basis the identity (initial default value) for the reduction * @param reducer a commutative associative combining function * @return the result of accumulating the given transformation * of all entries + * @since 1.8 */ - public int reduceEntriesToIntInParallel - (ObjectToInt> transformer, - int basis, - IntByIntToInt reducer) { - return ForkJoinTasks.reduceEntriesToInt - (this, transformer, basis, reducer).invoke(); + public long reduceEntriesToLong(long parallelismThreshold, + ObjectToLong> transformer, + long basis, + LongByLongToLong reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesToLongTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); + } + + /** + * Returns the result of accumulating the given transformation + * of all entries using the given reducer to combine values, + * and the given basis as an identity value. + * + * @param parallelismThreshold the (estimated) number of elements + * needed for this operation to be executed in parallel + * @param transformer a function returning the transformation + * for an element + * @param basis the identity (initial default value) for the reduction + * @param reducer a commutative associative combining function + * @return the result of accumulating the given transformation + * of all entries + * @since 1.8 + */ + public int reduceEntriesToInt(long parallelismThreshold, + ObjectToInt> transformer, + int basis, + IntByIntToInt reducer) { + if (transformer == null || reducer == null) + throw new NullPointerException(); + return new MapReduceEntriesToIntTask + (null, batchFor(parallelismThreshold), 0, 0, table, + null, transformer, basis, reducer).invoke(); } @@ -4578,9 +4132,11 @@ public class ConcurrentHashMapV8 /** * Base class for views. */ - abstract static class CHMView { + abstract static class CollectionView + implements Collection, java.io.Serializable { + private static final long serialVersionUID = 7249069246763182397L; final ConcurrentHashMapV8 map; - CHMView(ConcurrentHashMapV8 map) { this.map = map; } + CollectionView(ConcurrentHashMapV8 map) { this.map = map; } /** * Returns the map backing this view. @@ -4589,12 +4145,25 @@ public class ConcurrentHashMapV8 */ public ConcurrentHashMapV8 getMap() { return map; } - public final int size() { return map.size(); } - public final boolean isEmpty() { return map.isEmpty(); } - public final void clear() { map.clear(); } + /** + * Removes all of the elements from this view, by removing all + * the mappings from the map backing this view. + */ + public final void clear() { map.clear(); } + public final int size() { return map.size(); } + public final boolean isEmpty() { return map.isEmpty(); } // implementations below rely on concrete classes supplying these - public abstract Iterator iterator(); + // abstract methods + /** + * Returns a "weakly consistent" iterator that will never + * throw {@link ConcurrentModificationException}, and + * guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not + * guaranteed to) reflect any modifications subsequent to + * construction. + */ + public abstract Iterator iterator(); public abstract boolean contains(Object o); public abstract boolean remove(Object o); @@ -4602,13 +4171,12 @@ public class ConcurrentHashMapV8 public final Object[] toArray() { long sz = map.mappingCount(); - if (sz > (long)(MAX_ARRAY_SIZE)) + if (sz > MAX_ARRAY_SIZE) throw new OutOfMemoryError(oomeMsg); int n = (int)sz; Object[] r = new Object[n]; int i = 0; - Iterator it = iterator(); - while (it.hasNext()) { + for (E e : this) { if (i == n) { if (n >= MAX_ARRAY_SIZE) throw new OutOfMemoryError(oomeMsg); @@ -4618,14 +4186,15 @@ public class ConcurrentHashMapV8 n += (n >>> 1) + 1; r = Arrays.copyOf(r, n); } - r[i++] = it.next(); + r[i++] = e; } return (i == n) ? r : Arrays.copyOf(r, i); } - @SuppressWarnings("unchecked") public final T[] toArray(T[] a) { + @SuppressWarnings("unchecked") + public final T[] toArray(T[] a) { long sz = map.mappingCount(); - if (sz > (long)(MAX_ARRAY_SIZE)) + if (sz > MAX_ARRAY_SIZE) throw new OutOfMemoryError(oomeMsg); int m = (int)sz; T[] r = (a.length >= m) ? a : @@ -4633,8 +4202,7 @@ public class ConcurrentHashMapV8 .newInstance(a.getClass().getComponentType(), m); int n = r.length; int i = 0; - Iterator it = iterator(); - while (it.hasNext()) { + for (E e : this) { if (i == n) { if (n >= MAX_ARRAY_SIZE) throw new OutOfMemoryError(oomeMsg); @@ -4644,7 +4212,7 @@ public class ConcurrentHashMapV8 n += (n >>> 1) + 1; r = Arrays.copyOf(r, n); } - r[i++] = (T)it.next(); + r[i++] = (T)e; } if (a == r && i < n) { r[i] = null; // null-terminate @@ -4653,17 +4221,21 @@ public class ConcurrentHashMapV8 return (i == n) ? r : Arrays.copyOf(r, i); } - public final int hashCode() { - int h = 0; - for (Iterator it = iterator(); it.hasNext();) - h += it.next().hashCode(); - return h; - } - + /** + * Returns a string representation of this collection. + * The string representation consists of the string representations + * of the collection's elements in the order they are returned by + * its iterator, enclosed in square brackets ({@code "[]"}). + * Adjacent elements are separated by the characters {@code ", "} + * (comma and space). Elements are converted to strings as by + * {@link String#valueOf(Object)}. + * + * @return a string representation of this collection + */ public final String toString() { StringBuilder sb = new StringBuilder(); sb.append('['); - Iterator it = iterator(); + Iterator it = iterator(); if (it.hasNext()) { for (;;) { Object e = it.next(); @@ -4678,8 +4250,7 @@ public class ConcurrentHashMapV8 public final boolean containsAll(Collection c) { if (c != this) { - for (Iterator it = c.iterator(); it.hasNext();) { - Object e = it.next(); + for (Object e : c) { if (e == null || !contains(e)) return false; } @@ -4689,7 +4260,7 @@ public class ConcurrentHashMapV8 public final boolean removeAll(Collection c) { boolean modified = false; - for (Iterator it = iterator(); it.hasNext();) { + for (Iterator it = iterator(); it.hasNext();) { if (c.contains(it.next())) { it.remove(); modified = true; @@ -4700,7 +4271,7 @@ public class ConcurrentHashMapV8 public final boolean retainAll(Collection c) { boolean modified = false; - for (Iterator it = iterator(); it.hasNext();) { + for (Iterator it = iterator(); it.hasNext();) { if (!c.contains(it.next())) { it.remove(); modified = true; @@ -4714,11 +4285,15 @@ public class ConcurrentHashMapV8 /** * A view of a ConcurrentHashMapV8 as a {@link Set} of keys, in * which additions may optionally be enabled by mapping to a - * common value. This class cannot be directly instantiated. See - * {@link #keySet()}, {@link #keySet(Object)}, {@link #newKeySet()}, - * {@link #newKeySet(int)}. + * common value. This class cannot be directly instantiated. + * See {@link #keySet() keySet()}, + * {@link #keySet(Object) keySet(V)}, + * {@link #newKeySet() newKeySet()}, + * {@link #newKeySet(int) newKeySet(int)}. + * + * @since 1.8 */ - public static class KeySetView extends CHMView + public static class KeySetView extends CollectionView implements Set, java.io.Serializable { private static final long serialVersionUID = 7249069246763182397L; private final V value; @@ -4736,66 +4311,122 @@ public class ConcurrentHashMapV8 */ public V getMappedValue() { return value; } - // implement Set API - + /** + * {@inheritDoc} + * @throws NullPointerException if the specified key is null + */ public boolean contains(Object o) { return map.containsKey(o); } - public boolean remove(Object o) { return map.remove(o) != null; } /** - * Returns a "weakly consistent" iterator that will never - * throw {@link ConcurrentModificationException}, and - * guarantees to traverse elements as they existed upon - * construction of the iterator, and may (but is not - * guaranteed to) reflect any modifications subsequent to - * construction. + * Removes the key from this map view, by removing the key (and its + * corresponding value) from the backing map. This method does + * nothing if the key is not in the map. * - * @return an iterator over the keys of this map + * @param o the key to be removed from the backing map + * @return {@code true} if the backing map contained the specified key + * @throws NullPointerException if the specified key is null + */ + public boolean remove(Object o) { return map.remove(o) != null; } + + /** + * @return an iterator over the keys of the backing map + */ + public Iterator iterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + int f = (t = m.table) == null ? 0 : t.length; + return new KeyIterator(t, f, 0, f, m); + } + + /** + * Adds the specified key to this set view by mapping the key to + * the default mapped value in the backing map, if defined. + * + * @param e key to be added + * @return {@code true} if this set changed as a result of the call + * @throws NullPointerException if the specified key is null + * @throws UnsupportedOperationException if no default mapped value + * for additions was provided */ - public Iterator iterator() { return new KeyIterator(map); } public boolean add(K e) { V v; if ((v = value) == null) throw new UnsupportedOperationException(); - return map.internalPut(e, v, true) == null; + return map.putVal(e, v, true) == null; } + + /** + * Adds all of the elements in the specified collection to this set, + * as if by calling {@link #add} on each one. + * + * @param c the elements to be inserted into this set + * @return {@code true} if this set changed as a result of the call + * @throws NullPointerException if the collection or any of its + * elements are {@code null} + * @throws UnsupportedOperationException if no default mapped value + * for additions was provided + */ public boolean addAll(Collection c) { boolean added = false; V v; if ((v = value) == null) throw new UnsupportedOperationException(); for (K e : c) { - if (map.internalPut(e, v, true) == null) + if (map.putVal(e, v, true) == null) added = true; } return added; } + + public int hashCode() { + int h = 0; + for (K e : this) + h += e.hashCode(); + return h; + } + public boolean equals(Object o) { Set c; return ((o instanceof Set) && ((c = (Set)o) == this || (containsAll(c) && c.containsAll(this)))); } + + public ConcurrentHashMapSpliterator spliterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new KeySpliterator(t, f, 0, f, n < 0L ? 0L : n); + } + + public void forEach(Action action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + action.apply(p.key); + } + } } /** * A view of a ConcurrentHashMapV8 as a {@link Collection} of * values, in which additions are disabled. This class cannot be * directly instantiated. See {@link #values()}. - * - *

The view's {@code iterator} is a "weakly consistent" iterator - * that will never throw {@link ConcurrentModificationException}, - * and guarantees to traverse elements as they existed upon - * construction of the iterator, and may (but is not guaranteed to) - * reflect any modifications subsequent to construction. */ - public static final class ValuesView extends CHMView - implements Collection { - ValuesView(ConcurrentHashMapV8 map) { super(map); } - public final boolean contains(Object o) { return map.containsValue(o); } + static final class ValuesView extends CollectionView + implements Collection, java.io.Serializable { + private static final long serialVersionUID = 2249069246763182397L; + ValuesView(ConcurrentHashMapV8 map) { super(map); } + public final boolean contains(Object o) { + return map.containsValue(o); + } + public final boolean remove(Object o) { if (o != null) { - Iterator it = new ValueIterator(map); - while (it.hasNext()) { + for (Iterator it = iterator(); it.hasNext();) { if (o.equals(it.next())) { it.remove(); return true; @@ -4805,19 +4436,13 @@ public class ConcurrentHashMapV8 return false; } - /** - * Returns a "weakly consistent" iterator that will never - * throw {@link ConcurrentModificationException}, and - * guarantees to traverse elements as they existed upon - * construction of the iterator, and may (but is not - * guaranteed to) reflect any modifications subsequent to - * construction. - * - * @return an iterator over the values of this map - */ public final Iterator iterator() { - return new ValueIterator(map); + ConcurrentHashMapV8 m = map; + Node[] t; + int f = (t = m.table) == null ? 0 : t.length; + return new ValueIterator(t, f, 0, f, m); } + public final boolean add(V e) { throw new UnsupportedOperationException(); } @@ -4825,6 +4450,23 @@ public class ConcurrentHashMapV8 throw new UnsupportedOperationException(); } + public ConcurrentHashMapSpliterator spliterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new ValueSpliterator(t, f, 0, f, n < 0L ? 0L : n); + } + + public void forEach(Action action) { + if (action == null) throw new NullPointerException(); + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + action.apply(p.val); + } + } } /** @@ -4832,10 +4474,12 @@ public class ConcurrentHashMapV8 * entries. This class cannot be directly instantiated. See * {@link #entrySet()}. */ - public static final class EntrySetView extends CHMView - implements Set> { + static final class EntrySetView extends CollectionView> + implements Set>, java.io.Serializable { + private static final long serialVersionUID = 2249069246763182397L; EntrySetView(ConcurrentHashMapV8 map) { super(map); } - public final boolean contains(Object o) { + + public boolean contains(Object o) { Object k, v, r; Map.Entry e; return ((o instanceof Map.Entry) && (k = (e = (Map.Entry)o).getKey()) != null && @@ -4843,7 +4487,8 @@ public class ConcurrentHashMapV8 (v = e.getValue()) != null && (v == r || v.equals(r))); } - public final boolean remove(Object o) { + + public boolean remove(Object o) { Object k, v; Map.Entry e; return ((o instanceof Map.Entry) && (k = (e = (Map.Entry)o).getKey()) != null && @@ -4852,23 +4497,20 @@ public class ConcurrentHashMapV8 } /** - * Returns a "weakly consistent" iterator that will never - * throw {@link ConcurrentModificationException}, and - * guarantees to traverse elements as they existed upon - * construction of the iterator, and may (but is not - * guaranteed to) reflect any modifications subsequent to - * construction. - * - * @return an iterator over the entries of this map + * @return an iterator over the entries of the backing map */ - public final Iterator> iterator() { - return new EntryIterator(map); + public Iterator> iterator() { + ConcurrentHashMapV8 m = map; + Node[] t; + int f = (t = m.table) == null ? 0 : t.length; + return new EntryIterator(t, f, 0, f, m); } - public final boolean add(Entry e) { - return map.internalPut(e.getKey(), e.getValue(), false) == null; + public boolean add(Entry e) { + return map.putVal(e.getKey(), e.getValue(), false) == null; } - public final boolean addAll(Collection> c) { + + public boolean addAll(Collection> c) { boolean added = false; for (Entry e : c) { if (add(e)) @@ -4876,681 +4518,106 @@ public class ConcurrentHashMapV8 } return added; } - public boolean equals(Object o) { + + public final int hashCode() { + int h = 0; + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + h += p.hashCode(); + } + } + return h; + } + + public final boolean equals(Object o) { Set c; return ((o instanceof Set) && ((c = (Set)o) == this || (containsAll(c) && c.containsAll(this)))); } - } - // --------------------------------------------------------------------- + public ConcurrentHashMapSpliterator> spliterator() { + Node[] t; + ConcurrentHashMapV8 m = map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new EntrySpliterator(t, f, 0, f, n < 0L ? 0L : n, m); + } - /** - * Predefined tasks for performing bulk parallel operations on - * ConcurrentHashMapV8s. These tasks follow the forms and rules used - * for bulk operations. Each method has the same name, but returns - * a task rather than invoking it. These methods may be useful in - * custom applications such as submitting a task without waiting - * for completion, using a custom pool, or combining with other - * tasks. - */ - public static class ForkJoinTasks { - private ForkJoinTasks() {} - - /** - * Returns a task that when invoked, performs the given - * action for each (key, value) - * - * @param map the map - * @param action the action - * @return the task - */ - public static ForkJoinTask forEach - (ConcurrentHashMapV8 map, - BiAction action) { + public void forEach(Action> action) { if (action == null) throw new NullPointerException(); - return new ForEachMappingTask(map, null, -1, action); + Node[] t; + if ((t = map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) + action.apply(new MapEntry(p.key, p.val, map)); + } } - /** - * Returns a task that when invoked, performs the given - * action for each non-null transformation of each (key, value) - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - * @return the task - */ - public static ForkJoinTask forEach - (ConcurrentHashMapV8 map, - BiFun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - return new ForEachTransformedMappingTask - (map, null, -1, transformer, action); - } - - /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each (key, - * value), or null if none. Upon success, further element - * processing is suppressed and the results of any other - * parallel invocations of the search function are ignored. - * - * @param map the map - * @param searchFunction a function returning a non-null - * result on success, else null - * @return the task - */ - public static ForkJoinTask search - (ConcurrentHashMapV8 map, - BiFun searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - return new SearchMappingsTask - (map, null, -1, searchFunction, - new AtomicReference()); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all (key, value) pairs - * using the given reducer to combine values, or null if none. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduce - (ConcurrentHashMapV8 map, - BiFun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceMappingsTask - (map, null, -1, null, transformer, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all (key, value) pairs - * using the given reducer to combine values, and the given - * basis as an identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceToDouble - (ConcurrentHashMapV8 map, - ObjectByObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceMappingsToDoubleTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all (key, value) pairs - * using the given reducer to combine values, and the given - * basis as an identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceToLong - (ConcurrentHashMapV8 map, - ObjectByObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceMappingsToLongTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all (key, value) pairs - * using the given reducer to combine values, and the given - * basis as an identity value. - * - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceToInt - (ConcurrentHashMapV8 map, - ObjectByObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceMappingsToIntTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, performs the given action - * for each key. - * - * @param map the map - * @param action the action - * @return the task - */ - public static ForkJoinTask forEachKey - (ConcurrentHashMapV8 map, - Action action) { - if (action == null) throw new NullPointerException(); - return new ForEachKeyTask(map, null, -1, action); - } - - /** - * Returns a task that when invoked, performs the given action - * for each non-null transformation of each key. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - * @return the task - */ - public static ForkJoinTask forEachKey - (ConcurrentHashMapV8 map, - Fun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - return new ForEachTransformedKeyTask - (map, null, -1, transformer, action); - } - - /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each key, or - * null if none. Upon success, further element processing is - * suppressed and the results of any other parallel - * invocations of the search function are ignored. - * - * @param map the map - * @param searchFunction a function returning a non-null - * result on success, else null - * @return the task - */ - public static ForkJoinTask searchKeys - (ConcurrentHashMapV8 map, - Fun searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - return new SearchKeysTask - (map, null, -1, searchFunction, - new AtomicReference()); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating all keys using the given reducer to combine - * values, or null if none. - * - * @param map the map - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceKeys - (ConcurrentHashMapV8 map, - BiFun reducer) { - if (reducer == null) throw new NullPointerException(); - return new ReduceKeysTask - (map, null, -1, null, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all keys using the given - * reducer to combine values, or null if none. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceKeys - (ConcurrentHashMapV8 map, - Fun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceKeysTask - (map, null, -1, null, transformer, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all keys using the given - * reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceKeysToDouble - (ConcurrentHashMapV8 map, - ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceKeysToDoubleTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all keys using the given - * reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceKeysToLong - (ConcurrentHashMapV8 map, - ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceKeysToLongTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all keys using the given - * reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceKeysToInt - (ConcurrentHashMapV8 map, - ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceKeysToIntTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, performs the given action - * for each value. - * - * @param map the map - * @param action the action - */ - public static ForkJoinTask forEachValue - (ConcurrentHashMapV8 map, - Action action) { - if (action == null) throw new NullPointerException(); - return new ForEachValueTask(map, null, -1, action); - } - - /** - * Returns a task that when invoked, performs the given action - * for each non-null transformation of each value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - */ - public static ForkJoinTask forEachValue - (ConcurrentHashMapV8 map, - Fun transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - return new ForEachTransformedValueTask - (map, null, -1, transformer, action); - } - - /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each value, or - * null if none. Upon success, further element processing is - * suppressed and the results of any other parallel - * invocations of the search function are ignored. - * - * @param map the map - * @param searchFunction a function returning a non-null - * result on success, else null - * @return the task - */ - public static ForkJoinTask searchValues - (ConcurrentHashMapV8 map, - Fun searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - return new SearchValuesTask - (map, null, -1, searchFunction, - new AtomicReference()); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating all values using the given reducer to combine - * values, or null if none. - * - * @param map the map - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceValues - (ConcurrentHashMapV8 map, - BiFun reducer) { - if (reducer == null) throw new NullPointerException(); - return new ReduceValuesTask - (map, null, -1, null, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all values using the - * given reducer to combine values, or null if none. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceValues - (ConcurrentHashMapV8 map, - Fun transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceValuesTask - (map, null, -1, null, transformer, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all values using the - * given reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceValuesToDouble - (ConcurrentHashMapV8 map, - ObjectToDouble transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceValuesToDoubleTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all values using the - * given reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceValuesToLong - (ConcurrentHashMapV8 map, - ObjectToLong transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceValuesToLongTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all values using the - * given reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceValuesToInt - (ConcurrentHashMapV8 map, - ObjectToInt transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceValuesToIntTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, perform the given action - * for each entry. - * - * @param map the map - * @param action the action - */ - public static ForkJoinTask forEachEntry - (ConcurrentHashMapV8 map, - Action> action) { - if (action == null) throw new NullPointerException(); - return new ForEachEntryTask(map, null, -1, action); - } - - /** - * Returns a task that when invoked, perform the given action - * for each non-null transformation of each entry. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case the action is not applied) - * @param action the action - */ - public static ForkJoinTask forEachEntry - (ConcurrentHashMapV8 map, - Fun, ? extends U> transformer, - Action action) { - if (transformer == null || action == null) - throw new NullPointerException(); - return new ForEachTransformedEntryTask - (map, null, -1, transformer, action); - } - - /** - * Returns a task that when invoked, returns a non-null result - * from applying the given search function on each entry, or - * null if none. Upon success, further element processing is - * suppressed and the results of any other parallel - * invocations of the search function are ignored. - * - * @param map the map - * @param searchFunction a function returning a non-null - * result on success, else null - * @return the task - */ - public static ForkJoinTask searchEntries - (ConcurrentHashMapV8 map, - Fun, ? extends U> searchFunction) { - if (searchFunction == null) throw new NullPointerException(); - return new SearchEntriesTask - (map, null, -1, searchFunction, - new AtomicReference()); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating all entries using the given reducer to combine - * values, or null if none. - * - * @param map the map - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask> reduceEntries - (ConcurrentHashMapV8 map, - BiFun, Map.Entry, ? extends Map.Entry> reducer) { - if (reducer == null) throw new NullPointerException(); - return new ReduceEntriesTask - (map, null, -1, null, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all entries using the - * given reducer to combine values, or null if none. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element, or null if there is no transformation (in - * which case it is not combined) - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceEntries - (ConcurrentHashMapV8 map, - Fun, ? extends U> transformer, - BiFun reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceEntriesTask - (map, null, -1, null, transformer, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all entries using the - * given reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceEntriesToDouble - (ConcurrentHashMapV8 map, - ObjectToDouble> transformer, - double basis, - DoubleByDoubleToDouble reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceEntriesToDoubleTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all entries using the - * given reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceEntriesToLong - (ConcurrentHashMapV8 map, - ObjectToLong> transformer, - long basis, - LongByLongToLong reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceEntriesToLongTask - (map, null, -1, null, transformer, basis, reducer); - } - - /** - * Returns a task that when invoked, returns the result of - * accumulating the given transformation of all entries using the - * given reducer to combine values, and the given basis as an - * identity value. - * - * @param map the map - * @param transformer a function returning the transformation - * for an element - * @param basis the identity (initial default value) for the reduction - * @param reducer a commutative associative combining function - * @return the task - */ - public static ForkJoinTask reduceEntriesToInt - (ConcurrentHashMapV8 map, - ObjectToInt> transformer, - int basis, - IntByIntToInt reducer) { - if (transformer == null || reducer == null) - throw new NullPointerException(); - return new MapReduceEntriesToIntTask - (map, null, -1, null, transformer, basis, reducer); - } } // ------------------------------------------------------- + /** + * Base class for bulk tasks. Repeats some fields and code from + * class Traverser, because we need to subclass CountedCompleter. + */ + abstract static class BulkTask extends CountedCompleter { + Node[] tab; // same as Traverser + Node next; + int index; + int baseIndex; + int baseLimit; + final int baseSize; + int batch; // split control + + BulkTask(BulkTask par, int b, int i, int f, Node[] t) { + super(par); + this.batch = b; + this.index = this.baseIndex = i; + if ((this.tab = t) == null) + this.baseSize = this.baseLimit = 0; + else if (par == null) + this.baseSize = this.baseLimit = t.length; + else { + this.baseLimit = f; + this.baseSize = par.baseSize; + } + } + + /** + * Same as Traverser version + */ + final Node advance() { + Node e; + if ((e = next) != null) + e = e.next; + for (;;) { + Node[] t; int i, n; K ek; // must use locals in checks + if (e != null) + return next = e; + if (baseIndex >= baseLimit || (t = tab) == null || + (n = t.length) <= (i = index) || i < 0) + return next = null; + if ((e = tabAt(t, index)) != null && e.hash < 0) { + if (e instanceof ForwardingNode) { + tab = ((ForwardingNode)e).nextTable; + e = null; + continue; + } + else if (e instanceof TreeBin) + e = ((TreeBin)e).first; + else + e = null; + } + if ((index += baseSize) >= n) + index = ++baseIndex; // visit upper slots if present + } + } + } + /* * Task classes. Coded in a regular but ugly format/style to * simplify checks that each variant differs in the right way from @@ -5558,115 +4625,140 @@ public class ConcurrentHashMapV8 * that we've already null-checked task arguments, so we force * simplest hoisted bypass to help avoid convoluted traps. */ - - @SuppressWarnings("serial") static final class ForEachKeyTask - extends Traverser { - final Action action; + @SuppressWarnings("serial") + static final class ForEachKeyTask + extends BulkTask { + final Action action; ForEachKeyTask - (ConcurrentHashMapV8 m, Traverser p, int b, - Action action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + Action action) { + super(p, b, i, f, t); this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { - final Action action; + public final void compute() { + final Action action; if ((action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) - new ForEachKeyTask(map, this, b, action).fork(); - while (advance() != null) - action.apply((K)nextKey); + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachKeyTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null;) + action.apply(p.key); propagateCompletion(); } } } - @SuppressWarnings("serial") static final class ForEachValueTask - extends Traverser { - final Action action; + @SuppressWarnings("serial") + static final class ForEachValueTask + extends BulkTask { + final Action action; ForEachValueTask - (ConcurrentHashMapV8 m, Traverser p, int b, - Action action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + Action action) { + super(p, b, i, f, t); this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { - final Action action; + public final void compute() { + final Action action; if ((action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) - new ForEachValueTask(map, this, b, action).fork(); - V v; - while ((v = advance()) != null) - action.apply(v); + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachValueTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null;) + action.apply(p.val); propagateCompletion(); } } } - @SuppressWarnings("serial") static final class ForEachEntryTask - extends Traverser { - final Action> action; + @SuppressWarnings("serial") + static final class ForEachEntryTask + extends BulkTask { + final Action> action; ForEachEntryTask - (ConcurrentHashMapV8 m, Traverser p, int b, - Action> action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + Action> action) { + super(p, b, i, f, t); this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { - final Action> action; + public final void compute() { + final Action> action; if ((action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) - new ForEachEntryTask(map, this, b, action).fork(); - V v; - while ((v = advance()) != null) - action.apply(entryFor((K)nextKey, v)); + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachEntryTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null; ) + action.apply(p); propagateCompletion(); } } } - @SuppressWarnings("serial") static final class ForEachMappingTask - extends Traverser { - final BiAction action; + @SuppressWarnings("serial") + static final class ForEachMappingTask + extends BulkTask { + final BiAction action; ForEachMappingTask - (ConcurrentHashMapV8 m, Traverser p, int b, - BiAction action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + BiAction action) { + super(p, b, i, f, t); this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { - final BiAction action; + public final void compute() { + final BiAction action; if ((action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) - new ForEachMappingTask(map, this, b, action).fork(); - V v; - while ((v = advance()) != null) - action.apply((K)nextKey, v); + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); + new ForEachMappingTask + (this, batch >>>= 1, baseLimit = h, f, tab, + action).fork(); + } + for (Node p; (p = advance()) != null; ) + action.apply(p.key, p.val); propagateCompletion(); } } } - @SuppressWarnings("serial") static final class ForEachTransformedKeyTask - extends Traverser { + @SuppressWarnings("serial") + static final class ForEachTransformedKeyTask + extends BulkTask { final Fun transformer; - final Action action; + final Action action; ForEachTransformedKeyTask - (ConcurrentHashMapV8 m, Traverser p, int b, - Fun transformer, Action action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + Fun transformer, Action action) { + super(p, b, i, f, t); this.transformer = transformer; this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun transformer; - final Action action; + final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); new ForEachTransformedKeyTask - (map, this, b, transformer, action).fork(); - U u; - while (advance() != null) { - if ((u = transformer.apply((K)nextKey)) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key)) != null) action.apply(u); } propagateCompletion(); @@ -5674,27 +4766,32 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class ForEachTransformedValueTask - extends Traverser { + @SuppressWarnings("serial") + static final class ForEachTransformedValueTask + extends BulkTask { final Fun transformer; - final Action action; + final Action action; ForEachTransformedValueTask - (ConcurrentHashMapV8 m, Traverser p, int b, - Fun transformer, Action action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + Fun transformer, Action action) { + super(p, b, i, f, t); this.transformer = transformer; this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun transformer; - final Action action; + final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); new ForEachTransformedValueTask - (map, this, b, transformer, action).fork(); - V v; U u; - while ((v = advance()) != null) { - if ((u = transformer.apply(v)) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.val)) != null) action.apply(u); } propagateCompletion(); @@ -5702,28 +4799,32 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class ForEachTransformedEntryTask - extends Traverser { + @SuppressWarnings("serial") + static final class ForEachTransformedEntryTask + extends BulkTask { final Fun, ? extends U> transformer; - final Action action; + final Action action; ForEachTransformedEntryTask - (ConcurrentHashMapV8 m, Traverser p, int b, - Fun, ? extends U> transformer, Action action) { - super(m, p, b); + (BulkTask p, int b, int i, int f, Node[] t, + Fun, ? extends U> transformer, Action action) { + super(p, b, i, f, t); this.transformer = transformer; this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun, ? extends U> transformer; - final Action action; + final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); new ForEachTransformedEntryTask - (map, this, b, transformer, action).fork(); - V v; U u; - while ((v = advance()) != null) { - if ((u = transformer.apply(entryFor((K)nextKey, - v))) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p)) != null) action.apply(u); } propagateCompletion(); @@ -5731,28 +4832,33 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class ForEachTransformedMappingTask - extends Traverser { + @SuppressWarnings("serial") + static final class ForEachTransformedMappingTask + extends BulkTask { final BiFun transformer; - final Action action; + final Action action; ForEachTransformedMappingTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, BiFun transformer, - Action action) { - super(m, p, b); + Action action) { + super(p, b, i, f, t); this.transformer = transformer; this.action = action; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final BiFun transformer; - final Action action; + final Action action; if ((transformer = this.transformer) != null && (action = this.action) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); new ForEachTransformedMappingTask - (map, this, b, transformer, action).fork(); - V v; U u; - while ((v = advance()) != null) { - if ((u = transformer.apply((K)nextKey, v)) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + transformer, action).fork(); + } + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key, p.val)) != null) action.apply(u); } propagateCompletion(); @@ -5760,38 +4866,41 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class SearchKeysTask - extends Traverser { + @SuppressWarnings("serial") + static final class SearchKeysTask + extends BulkTask { final Fun searchFunction; final AtomicReference result; SearchKeysTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, Fun searchFunction, AtomicReference result) { - super(m, p, b); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { - for (int b;;) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { if (result.get() != null) return; - if ((b = preSplit()) <= 0) - break; + addToPendingCount(1); new SearchKeysTask - (map, this, b, searchFunction, result).fork(); + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); } while (result.get() == null) { U u; - if (advance() == null) { + Node p; + if ((p = advance()) == null) { propagateCompletion(); break; } - if ((u = searchFunction.apply((K)nextKey)) != null) { + if ((u = searchFunction.apply(p.key)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); break; @@ -5801,38 +4910,41 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class SearchValuesTask - extends Traverser { + @SuppressWarnings("serial") + static final class SearchValuesTask + extends BulkTask { final Fun searchFunction; final AtomicReference result; SearchValuesTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, Fun searchFunction, AtomicReference result) { - super(m, p, b); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { - for (int b;;) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { if (result.get() != null) return; - if ((b = preSplit()) <= 0) - break; + addToPendingCount(1); new SearchValuesTask - (map, this, b, searchFunction, result).fork(); + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); } while (result.get() == null) { - V v; U u; - if ((v = advance()) == null) { + U u; + Node p; + if ((p = advance()) == null) { propagateCompletion(); break; } - if ((u = searchFunction.apply(v)) != null) { + if ((u = searchFunction.apply(p.val)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); break; @@ -5842,39 +4954,41 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class SearchEntriesTask - extends Traverser { + @SuppressWarnings("serial") + static final class SearchEntriesTask + extends BulkTask { final Fun, ? extends U> searchFunction; final AtomicReference result; SearchEntriesTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, Fun, ? extends U> searchFunction, AtomicReference result) { - super(m, p, b); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun, ? extends U> searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { - for (int b;;) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { if (result.get() != null) return; - if ((b = preSplit()) <= 0) - break; + addToPendingCount(1); new SearchEntriesTask - (map, this, b, searchFunction, result).fork(); + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); } while (result.get() == null) { - V v; U u; - if ((v = advance()) == null) { + U u; + Node p; + if ((p = advance()) == null) { propagateCompletion(); break; } - if ((u = searchFunction.apply(entryFor((K)nextKey, - v))) != null) { + if ((u = searchFunction.apply(p)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); return; @@ -5884,38 +4998,41 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class SearchMappingsTask - extends Traverser { + @SuppressWarnings("serial") + static final class SearchMappingsTask + extends BulkTask { final BiFun searchFunction; final AtomicReference result; SearchMappingsTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, BiFun searchFunction, AtomicReference result) { - super(m, p, b); + super(p, b, i, f, t); this.searchFunction = searchFunction; this.result = result; } public final U getRawResult() { return result.get(); } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final BiFun searchFunction; final AtomicReference result; if ((searchFunction = this.searchFunction) != null && (result = this.result) != null) { - for (int b;;) { + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { if (result.get() != null) return; - if ((b = preSplit()) <= 0) - break; + addToPendingCount(1); new SearchMappingsTask - (map, this, b, searchFunction, result).fork(); + (this, batch >>>= 1, baseLimit = h, f, tab, + searchFunction, result).fork(); } while (result.get() == null) { - V v; U u; - if ((v = advance()) == null) { + U u; + Node p; + if ((p = advance()) == null) { propagateCompletion(); break; } - if ((u = searchFunction.apply((K)nextKey, v)) != null) { + if ((u = searchFunction.apply(p.key, p.val)) != null) { if (result.compareAndSet(null, u)) quietlyCompleteRoot(); break; @@ -5925,34 +5042,39 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class ReduceKeysTask - extends Traverser { + @SuppressWarnings("serial") + static final class ReduceKeysTask + extends BulkTask { final BiFun reducer; K result; ReduceKeysTask rights, nextRight; ReduceKeysTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, ReduceKeysTask nextRight, BiFun reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.reducer = reducer; } public final K getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final BiFun reducer; if ((reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new ReduceKeysTask - (map, this, b, rights, reducer)).fork(); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, reducer)).fork(); + } K r = null; - while (advance() != null) { - K u = (K)nextKey; - r = (r == null) ? u : reducer.apply(r, u); + for (Node p; (p = advance()) != null; ) { + K u = p.key; + r = (r == null) ? u : u == null ? r : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - ReduceKeysTask + @SuppressWarnings("unchecked") ReduceKeysTask t = (ReduceKeysTask)c, s = t.rights; while (s != null) { @@ -5967,35 +5089,39 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class ReduceValuesTask - extends Traverser { + @SuppressWarnings("serial") + static final class ReduceValuesTask + extends BulkTask { final BiFun reducer; V result; ReduceValuesTask rights, nextRight; ReduceValuesTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, ReduceValuesTask nextRight, BiFun reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.reducer = reducer; } public final V getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final BiFun reducer; if ((reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new ReduceValuesTask - (map, this, b, rights, reducer)).fork(); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, reducer)).fork(); + } V r = null; - V v; - while ((v = advance()) != null) { - V u = v; - r = (r == null) ? u : reducer.apply(r, u); + for (Node p; (p = advance()) != null; ) { + V v = p.val; + r = (r == null) ? v : reducer.apply(r, v); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - ReduceValuesTask + @SuppressWarnings("unchecked") ReduceValuesTask t = (ReduceValuesTask)c, s = t.rights; while (s != null) { @@ -6010,35 +5136,37 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class ReduceEntriesTask - extends Traverser> { + @SuppressWarnings("serial") + static final class ReduceEntriesTask + extends BulkTask> { final BiFun, Map.Entry, ? extends Map.Entry> reducer; Map.Entry result; ReduceEntriesTask rights, nextRight; ReduceEntriesTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, ReduceEntriesTask nextRight, BiFun, Map.Entry, ? extends Map.Entry> reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.reducer = reducer; } public final Map.Entry getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final BiFun, Map.Entry, ? extends Map.Entry> reducer; if ((reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new ReduceEntriesTask - (map, this, b, rights, reducer)).fork(); - Map.Entry r = null; - V v; - while ((v = advance()) != null) { - Map.Entry u = entryFor((K)nextKey, v); - r = (r == null) ? u : reducer.apply(r, u); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, reducer)).fork(); } + Map.Entry r = null; + for (Node p; (p = advance()) != null; ) + r = (r == null) ? p : reducer.apply(r, p); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - ReduceEntriesTask + @SuppressWarnings("unchecked") ReduceEntriesTask t = (ReduceEntriesTask)c, s = t.rights; while (s != null) { @@ -6053,39 +5181,45 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceKeysTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceKeysTask + extends BulkTask { final Fun transformer; final BiFun reducer; U result; MapReduceKeysTask rights, nextRight; MapReduceKeysTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceKeysTask nextRight, Fun transformer, BiFun reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceKeysTask - (map, this, b, rights, transformer, reducer)).fork(); - U r = null, u; - while (advance() != null) { - if ((u = transformer.apply((K)nextKey)) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceKeysTask + @SuppressWarnings("unchecked") MapReduceKeysTask t = (MapReduceKeysTask)c, s = t.rights; while (s != null) { @@ -6100,40 +5234,45 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceValuesTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceValuesTask + extends BulkTask { final Fun transformer; final BiFun reducer; U result; MapReduceValuesTask rights, nextRight; MapReduceValuesTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceValuesTask nextRight, Fun transformer, BiFun reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceValuesTask - (map, this, b, rights, transformer, reducer)).fork(); - U r = null, u; - V v; - while ((v = advance()) != null) { - if ((u = transformer.apply(v)) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.val)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceValuesTask + @SuppressWarnings("unchecked") MapReduceValuesTask t = (MapReduceValuesTask)c, s = t.rights; while (s != null) { @@ -6148,41 +5287,45 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceEntriesTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceEntriesTask + extends BulkTask { final Fun, ? extends U> transformer; final BiFun reducer; U result; MapReduceEntriesTask rights, nextRight; MapReduceEntriesTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceEntriesTask nextRight, Fun, ? extends U> transformer, BiFun reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final Fun, ? extends U> transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceEntriesTask - (map, this, b, rights, transformer, reducer)).fork(); - U r = null, u; - V v; - while ((v = advance()) != null) { - if ((u = transformer.apply(entryFor((K)nextKey, - v))) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceEntriesTask + @SuppressWarnings("unchecked") MapReduceEntriesTask t = (MapReduceEntriesTask)c, s = t.rights; while (s != null) { @@ -6197,40 +5340,45 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceMappingsTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceMappingsTask + extends BulkTask { final BiFun transformer; final BiFun reducer; U result; MapReduceMappingsTask rights, nextRight; MapReduceMappingsTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceMappingsTask nextRight, BiFun transformer, BiFun reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.reducer = reducer; } public final U getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final BiFun transformer; final BiFun reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceMappingsTask - (map, this, b, rights, transformer, reducer)).fork(); - U r = null, u; - V v; - while ((v = advance()) != null) { - if ((u = transformer.apply((K)nextKey, v)) != null) + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, reducer)).fork(); + } + U r = null; + for (Node p; (p = advance()) != null; ) { + U u; + if ((u = transformer.apply(p.key, p.val)) != null) r = (r == null) ? u : reducer.apply(r, u); } result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceMappingsTask + @SuppressWarnings("unchecked") MapReduceMappingsTask t = (MapReduceMappingsTask)c, s = t.rights; while (s != null) { @@ -6245,39 +5393,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceKeysToDoubleTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceKeysToDoubleTask + extends BulkTask { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceKeysToDoubleTask rights, nextRight; MapReduceKeysToDoubleTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceKeysToDoubleTask nextRight, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceKeysToDoubleTask - (map, this, b, rights, transformer, r, reducer)).fork(); - while (advance() != null) - r = reducer.apply(r, transformer.apply((K)nextKey)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceKeysToDoubleTask + @SuppressWarnings("unchecked") MapReduceKeysToDoubleTask t = (MapReduceKeysToDoubleTask)c, s = t.rights; while (s != null) { @@ -6289,40 +5442,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceValuesToDoubleTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceValuesToDoubleTask + extends BulkTask { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceValuesToDoubleTask rights, nextRight; MapReduceValuesToDoubleTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceValuesToDoubleTask nextRight, ObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToDouble transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceValuesToDoubleTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply(v)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.val)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceValuesToDoubleTask + @SuppressWarnings("unchecked") MapReduceValuesToDoubleTask t = (MapReduceValuesToDoubleTask)c, s = t.rights; while (s != null) { @@ -6334,41 +5491,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceEntriesToDoubleTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceEntriesToDoubleTask + extends BulkTask { final ObjectToDouble> transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceEntriesToDoubleTask rights, nextRight; MapReduceEntriesToDoubleTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceEntriesToDoubleTask nextRight, ObjectToDouble> transformer, double basis, DoubleByDoubleToDouble reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToDouble> transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceEntriesToDoubleTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, - v))); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceEntriesToDoubleTask + @SuppressWarnings("unchecked") MapReduceEntriesToDoubleTask t = (MapReduceEntriesToDoubleTask)c, s = t.rights; while (s != null) { @@ -6380,40 +5540,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceMappingsToDoubleTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceMappingsToDoubleTask + extends BulkTask { final ObjectByObjectToDouble transformer; final DoubleByDoubleToDouble reducer; final double basis; double result; MapReduceMappingsToDoubleTask rights, nextRight; MapReduceMappingsToDoubleTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceMappingsToDoubleTask nextRight, ObjectByObjectToDouble transformer, double basis, DoubleByDoubleToDouble reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Double getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectByObjectToDouble transformer; final DoubleByDoubleToDouble reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { double r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceMappingsToDoubleTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply((K)nextKey, v)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key, p.val)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceMappingsToDoubleTask + @SuppressWarnings("unchecked") MapReduceMappingsToDoubleTask t = (MapReduceMappingsToDoubleTask)c, s = t.rights; while (s != null) { @@ -6425,39 +5589,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceKeysToLongTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceKeysToLongTask + extends BulkTask { final ObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceKeysToLongTask rights, nextRight; MapReduceKeysToLongTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceKeysToLongTask nextRight, ObjectToLong transformer, long basis, LongByLongToLong reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToLong transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceKeysToLongTask - (map, this, b, rights, transformer, r, reducer)).fork(); - while (advance() != null) - r = reducer.apply(r, transformer.apply((K)nextKey)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceKeysToLongTask + @SuppressWarnings("unchecked") MapReduceKeysToLongTask t = (MapReduceKeysToLongTask)c, s = t.rights; while (s != null) { @@ -6469,40 +5638,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceValuesToLongTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceValuesToLongTask + extends BulkTask { final ObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceValuesToLongTask rights, nextRight; MapReduceValuesToLongTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceValuesToLongTask nextRight, ObjectToLong transformer, long basis, LongByLongToLong reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToLong transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceValuesToLongTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply(v)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.val)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceValuesToLongTask + @SuppressWarnings("unchecked") MapReduceValuesToLongTask t = (MapReduceValuesToLongTask)c, s = t.rights; while (s != null) { @@ -6514,41 +5687,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceEntriesToLongTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceEntriesToLongTask + extends BulkTask { final ObjectToLong> transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceEntriesToLongTask rights, nextRight; MapReduceEntriesToLongTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceEntriesToLongTask nextRight, ObjectToLong> transformer, long basis, LongByLongToLong reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToLong> transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceEntriesToLongTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, - v))); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceEntriesToLongTask + @SuppressWarnings("unchecked") MapReduceEntriesToLongTask t = (MapReduceEntriesToLongTask)c, s = t.rights; while (s != null) { @@ -6560,40 +5736,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceMappingsToLongTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceMappingsToLongTask + extends BulkTask { final ObjectByObjectToLong transformer; final LongByLongToLong reducer; final long basis; long result; MapReduceMappingsToLongTask rights, nextRight; MapReduceMappingsToLongTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceMappingsToLongTask nextRight, ObjectByObjectToLong transformer, long basis, LongByLongToLong reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Long getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectByObjectToLong transformer; final LongByLongToLong reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { long r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceMappingsToLongTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply((K)nextKey, v)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key, p.val)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceMappingsToLongTask + @SuppressWarnings("unchecked") MapReduceMappingsToLongTask t = (MapReduceMappingsToLongTask)c, s = t.rights; while (s != null) { @@ -6605,39 +5785,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceKeysToIntTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceKeysToIntTask + extends BulkTask { final ObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceKeysToIntTask rights, nextRight; MapReduceKeysToIntTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceKeysToIntTask nextRight, ObjectToInt transformer, int basis, IntByIntToInt reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToInt transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceKeysToIntTask - (map, this, b, rights, transformer, r, reducer)).fork(); - while (advance() != null) - r = reducer.apply(r, transformer.apply((K)nextKey)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceKeysToIntTask + @SuppressWarnings("unchecked") MapReduceKeysToIntTask t = (MapReduceKeysToIntTask)c, s = t.rights; while (s != null) { @@ -6649,40 +5834,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceValuesToIntTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceValuesToIntTask + extends BulkTask { final ObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceValuesToIntTask rights, nextRight; MapReduceValuesToIntTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceValuesToIntTask nextRight, ObjectToInt transformer, int basis, IntByIntToInt reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToInt transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceValuesToIntTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply(v)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.val)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceValuesToIntTask + @SuppressWarnings("unchecked") MapReduceValuesToIntTask t = (MapReduceValuesToIntTask)c, s = t.rights; while (s != null) { @@ -6694,41 +5883,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceEntriesToIntTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceEntriesToIntTask + extends BulkTask { final ObjectToInt> transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceEntriesToIntTask rights, nextRight; MapReduceEntriesToIntTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceEntriesToIntTask nextRight, ObjectToInt> transformer, int basis, IntByIntToInt reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectToInt> transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceEntriesToIntTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply(entryFor((K)nextKey, - v))); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceEntriesToIntTask + @SuppressWarnings("unchecked") MapReduceEntriesToIntTask t = (MapReduceEntriesToIntTask)c, s = t.rights; while (s != null) { @@ -6740,40 +5932,44 @@ public class ConcurrentHashMapV8 } } - @SuppressWarnings("serial") static final class MapReduceMappingsToIntTask - extends Traverser { + @SuppressWarnings("serial") + static final class MapReduceMappingsToIntTask + extends BulkTask { final ObjectByObjectToInt transformer; final IntByIntToInt reducer; final int basis; int result; MapReduceMappingsToIntTask rights, nextRight; MapReduceMappingsToIntTask - (ConcurrentHashMapV8 m, Traverser p, int b, + (BulkTask p, int b, int i, int f, Node[] t, MapReduceMappingsToIntTask nextRight, ObjectByObjectToInt transformer, int basis, IntByIntToInt reducer) { - super(m, p, b); this.nextRight = nextRight; + super(p, b, i, f, t); this.nextRight = nextRight; this.transformer = transformer; this.basis = basis; this.reducer = reducer; } public final Integer getRawResult() { return result; } - @SuppressWarnings("unchecked") public final void compute() { + public final void compute() { final ObjectByObjectToInt transformer; final IntByIntToInt reducer; if ((transformer = this.transformer) != null && (reducer = this.reducer) != null) { int r = this.basis; - for (int b; (b = preSplit()) > 0;) + for (int i = baseIndex, f, h; batch > 0 && + (h = ((f = baseLimit) + i) >>> 1) > i;) { + addToPendingCount(1); (rights = new MapReduceMappingsToIntTask - (map, this, b, rights, transformer, r, reducer)).fork(); - V v; - while ((v = advance()) != null) - r = reducer.apply(r, transformer.apply((K)nextKey, v)); + (this, batch >>>= 1, baseLimit = h, f, tab, + rights, transformer, r, reducer)).fork(); + } + for (Node p; (p = advance()) != null; ) + r = reducer.apply(r, transformer.apply(p.key, p.val)); result = r; CountedCompleter c; for (c = firstComplete(); c != null; c = c.nextComplete()) { - MapReduceMappingsToIntTask + @SuppressWarnings("unchecked") MapReduceMappingsToIntTask t = (MapReduceMappingsToIntTask)c, s = t.rights; while (s != null) { @@ -6785,13 +5981,154 @@ public class ConcurrentHashMapV8 } } + /* ---------------- Counters -------------- */ + + // Adapted from LongAdder and Striped64. + // See their internal docs for explanation. + + // A padded cell for distributing counts + static final class CounterCell { + volatile long p0, p1, p2, p3, p4, p5, p6; + volatile long value; + volatile long q0, q1, q2, q3, q4, q5, q6; + CounterCell(long x) { value = x; } + } + + /** + * Holder for the thread-local hash code determining which + * CounterCell to use. The code is initialized via the + * counterHashCodeGenerator, but may be moved upon collisions. + */ + static final class CounterHashCode { + int code; + } + + /** + * Generates initial value for per-thread CounterHashCodes. + */ + static final AtomicInteger counterHashCodeGenerator = new AtomicInteger(); + + /** + * Increment for counterHashCodeGenerator. See class ThreadLocal + * for explanation. + */ + static final int SEED_INCREMENT = 0x61c88647; + + /** + * Per-thread counter hash codes. Shared across all instances. + */ + static final ThreadLocal threadCounterHashCode = + new ThreadLocal(); + + + final long sumCount() { + CounterCell[] as = counterCells; CounterCell a; + long sum = baseCount; + if (as != null) { + for (int i = 0; i < as.length; ++i) { + if ((a = as[i]) != null) + sum += a.value; + } + } + return sum; + } + + // See LongAdder version for explanation + private final void fullAddCount(long x, CounterHashCode hc, + boolean wasUncontended) { + int h; + if (hc == null) { + hc = new CounterHashCode(); + int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT); + h = hc.code = (s == 0) ? 1 : s; // Avoid zero + threadCounterHashCode.set(hc); + } + else + h = hc.code; + boolean collide = false; // True if last slot nonempty + for (;;) { + CounterCell[] as; CounterCell a; int n; long v; + if ((as = counterCells) != null && (n = as.length) > 0) { + if ((a = as[(n - 1) & h]) == null) { + if (cellsBusy == 0) { // Try to attach new Cell + CounterCell r = new CounterCell(x); // Optimistic create + if (cellsBusy == 0 && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + boolean created = false; + try { // Recheck under lock + CounterCell[] rs; int m, j; + if ((rs = counterCells) != null && + (m = rs.length) > 0 && + rs[j = (m - 1) & h] == null) { + rs[j] = r; + created = true; + } + } finally { + cellsBusy = 0; + } + if (created) + break; + continue; // Slot is now non-empty + } + } + collide = false; + } + else if (!wasUncontended) // CAS already known to fail + wasUncontended = true; // Continue after rehash + else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x)) + break; + else if (counterCells != as || n >= NCPU) + collide = false; // At max size or stale + else if (!collide) + collide = true; + else if (cellsBusy == 0 && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + try { + if (counterCells == as) {// Expand table unless stale + CounterCell[] rs = new CounterCell[n << 1]; + for (int i = 0; i < n; ++i) + rs[i] = as[i]; + counterCells = rs; + } + } finally { + cellsBusy = 0; + } + collide = false; + continue; // Retry with expanded table + } + h ^= h << 13; // Rehash + h ^= h >>> 17; + h ^= h << 5; + } + else if (cellsBusy == 0 && counterCells == as && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + boolean init = false; + try { // Initialize table + if (counterCells == as) { + CounterCell[] rs = new CounterCell[2]; + rs[h & 1] = new CounterCell(x); + counterCells = rs; + init = true; + } + } finally { + cellsBusy = 0; + } + if (init) + break; + } + else if (U.compareAndSwapLong(this, BASECOUNT, v = baseCount, v + x)) + break; // Fall back on using base + } + hc.code = h; // Record index for next time + } + // Unsafe mechanics private static final sun.misc.Unsafe U; private static final long SIZECTL; private static final long TRANSFERINDEX; private static final long TRANSFERORIGIN; private static final long BASECOUNT; - private static final long COUNTERBUSY; + private static final long CELLSBUSY; private static final long CELLVALUE; private static final long ABASE; private static final int ASHIFT; @@ -6808,14 +6145,14 @@ public class ConcurrentHashMapV8 (k.getDeclaredField("transferOrigin")); BASECOUNT = U.objectFieldOffset (k.getDeclaredField("baseCount")); - COUNTERBUSY = U.objectFieldOffset - (k.getDeclaredField("counterBusy")); + CELLSBUSY = U.objectFieldOffset + (k.getDeclaredField("cellsBusy")); Class ck = CounterCell.class; CELLVALUE = U.objectFieldOffset (ck.getDeclaredField("value")); - Class sc = Node[].class; - ABASE = U.arrayBaseOffset(sc); - int scale = U.arrayIndexScale(sc); + Class ak = Node[].class; + ABASE = U.arrayBaseOffset(ak); + int scale = U.arrayIndexScale(ak); if ((scale & (scale - 1)) != 0) throw new Error("data type scale not a power of two"); ASHIFT = 31 - Integer.numberOfLeadingZeros(scale); diff --git a/src/main/java/jsr166e/CountedCompleter.java b/src/main/java/jsr166e/CountedCompleter.java index c51f24d0914..d9d1d48132e 100644 --- a/src/main/java/jsr166e/CountedCompleter.java +++ b/src/main/java/jsr166e/CountedCompleter.java @@ -8,18 +8,19 @@ package jsr166e; /** * A {@link ForkJoinTask} with a completion action performed when - * triggered and there are no remaining pending - * actions. CountedCompleters are in general more robust in the + * triggered and there are no remaining pending actions. + * CountedCompleters are in general more robust in the * presence of subtask stalls and blockage than are other forms of * ForkJoinTasks, but are less intuitive to program. Uses of * CountedCompleter are similar to those of other completion based * components (such as {@link java.nio.channels.CompletionHandler}) * except that multiple pending completions may be necessary - * to trigger the {@link #onCompletion} action, not just one. Unless - * initialized otherwise, the {@link #getPendingCount pending count} - * starts at zero, but may be (atomically) changed using methods - * {@link #setPendingCount}, {@link #addToPendingCount}, and {@link - * #compareAndSetPendingCount}. Upon invocation of {@link + * to trigger the completion action {@link #onCompletion(CountedCompleter)}, + * not just one. + * Unless initialized otherwise, the {@linkplain #getPendingCount pending + * count} starts at zero, but may be (atomically) changed using + * methods {@link #setPendingCount}, {@link #addToPendingCount}, and + * {@link #compareAndSetPendingCount}. Upon invocation of {@link * #tryComplete}, if the pending action count is nonzero, it is * decremented; otherwise, the completion action is performed, and if * this completer itself has a completer, the process is continued @@ -40,9 +41,10 @@ package jsr166e; *

A concrete CountedCompleter class must define method {@link * #compute}, that should in most cases (as illustrated below), invoke * {@code tryComplete()} once before returning. The class may also - * optionally override method {@link #onCompletion} to perform an - * action upon normal completion, and method {@link - * #onExceptionalCompletion} to perform an action upon any exception. + * optionally override method {@link #onCompletion(CountedCompleter)} + * to perform an action upon normal completion, and method + * {@link #onExceptionalCompletion(Throwable, CountedCompleter)} to + * perform an action upon any exception. * *

CountedCompleters most often do not bear results, in which case * they are normally declared as {@code CountedCompleter}, and @@ -63,13 +65,14 @@ package jsr166e; * only as an internal helper for other computations, so its own task * status (as reported in methods such as {@link ForkJoinTask#isDone}) * is arbitrary; this status changes only upon explicit invocations of - * {@link #complete}, {@link ForkJoinTask#cancel}, {@link - * ForkJoinTask#completeExceptionally} or upon exceptional completion - * of method {@code compute}. Upon any exceptional completion, the - * exception may be relayed to a task's completer (and its completer, - * and so on), if one exists and it has not otherwise already - * completed. Similarly, cancelling an internal CountedCompleter has - * only a local effect on that completer, so is not often useful. + * {@link #complete}, {@link ForkJoinTask#cancel}, + * {@link ForkJoinTask#completeExceptionally(Throwable)} or upon + * exceptional completion of method {@code compute}. Upon any + * exceptional completion, the exception may be relayed to a task's + * completer (and its completer, and so on), if one exists and it has + * not otherwise already completed. Similarly, cancelling an internal + * CountedCompleter has only a local effect on that completer, so is + * not often useful. * *

Sample Usages. * @@ -96,8 +99,8 @@ package jsr166e; * improve load balancing. In the recursive case, the second of each * pair of subtasks to finish triggers completion of its parent * (because no result combination is performed, the default no-op - * implementation of method {@code onCompletion} is not overridden). A - * static utility method sets up the base task and invokes it + * implementation of method {@code onCompletion} is not overridden). + * A static utility method sets up the base task and invokes it * (here, implicitly using the {@link ForkJoinPool#commonPool()}). * * 

 {@code
@@ -152,12 +155,11 @@ package jsr166e;
  *   }
  * }
* - * As a further improvement, notice that the left task need not even - * exist. Instead of creating a new one, we can iterate using the - * original task, and add a pending count for each fork. Additionally, - * because no task in this tree implements an {@link #onCompletion} - * method, {@code tryComplete()} can be replaced with {@link - * #propagateCompletion}. + * As a further improvement, notice that the left task need not even exist. + * Instead of creating a new one, we can iterate using the original task, + * and add a pending count for each fork. Additionally, because no task + * in this tree implements an {@link #onCompletion(CountedCompleter)} method, + * {@code tryComplete()} can be replaced with {@link #propagateCompletion}. * * 
 {@code
  * class ForEach ...
@@ -235,7 +237,7 @@ package jsr166e;
  *
  * 
Recording subtasks. CountedCompleter tasks that combine
  * results of multiple subtasks usually need to access these results
- * in method {@link #onCompletion}. As illustrated in the following
+ * in method {@link #onCompletion(CountedCompleter)}. As illustrated in the following
  * class (that performs a simplified form of map-reduce where mappings
  * and reductions are all of type {@code E}), one way to do this in
  * divide and conquer designs is to have each subtask record its
@@ -336,7 +338,7 @@ package jsr166e;
  *     while (h - l >= 2) {
  *       int mid = (l + h) >>> 1;
  *       addToPendingCount(1);
- *       (forks = new MapReducer(this, array, mapper, reducer, mid, h, forks)).fork;
+ *       (forks = new MapReducer(this, array, mapper, reducer, mid, h, forks)).fork();
  *       h = mid;
  *     }
  *     if (h > l)
@@ -357,7 +359,7 @@ package jsr166e;
  *
  * 
Triggers. Some CountedCompleters are themselves never
  * forked, but instead serve as bits of plumbing in other designs;
- * including those in which the completion of one of more async tasks
+ * including those in which the completion of one or more async tasks
  * triggers another async task. For example:
  *
  * 
 {@code
@@ -437,20 +439,21 @@ public abstract class CountedCompleter extends ForkJoinTask {
     }
 
     /**
-     * Performs an action when method {@link #completeExceptionally}
-     * is invoked or method {@link #compute} throws an exception, and
-     * this task has not otherwise already completed normally. On
-     * entry to this method, this task {@link
-     * ForkJoinTask#isCompletedAbnormally}.  The return value of this
-     * method controls further propagation: If {@code true} and this
-     * task has a completer, then this completer is also completed
-     * exceptionally.  The default implementation of this method does
-     * nothing except return {@code true}.
+     * Performs an action when method {@link
+     * #completeExceptionally(Throwable)} is invoked or method {@link
+     * #compute} throws an exception, and this task has not already
+     * otherwise completed normally. On entry to this method, this task
+     * {@link ForkJoinTask#isCompletedAbnormally}.  The return value
+     * of this method controls further propagation: If {@code true}
+     * and this task has a completer that has not completed, then that
+     * completer is also completed exceptionally, with the same
+     * exception as this completer.  The default implementation of
+     * this method does nothing except return {@code true}.
      *
      * @param ex the exception
      * @param caller the task invoking this method (which may
      * be this task itself)
-     * @return true if this exception should be propagated to this
+     * @return {@code true} if this exception should be propagated to this
      * task's completer, if one exists
      */
     public boolean onExceptionalCompletion(Throwable ex, CountedCompleter caller) {
@@ -491,7 +494,7 @@ public abstract class CountedCompleter extends ForkJoinTask {
      * @param delta the value to add
      */
     public final void addToPendingCount(int delta) {
-        int c; // note: can replace with intrinsic in jdk8
+        int c;
         do {} while (!U.compareAndSwapInt(this, PENDING, c = pending, c+delta));
     }
 
@@ -501,7 +504,7 @@ public abstract class CountedCompleter extends ForkJoinTask {
      *
      * @param expected the expected value
      * @param count the new value
-     * @return true if successful
+     * @return {@code true} if successful
      */
     public final boolean compareAndSetPendingCount(int expected, int count) {
         return U.compareAndSwapInt(this, PENDING, expected, count);
@@ -535,9 +538,9 @@ public abstract class CountedCompleter extends ForkJoinTask {
 
     /**
      * If the pending count is nonzero, decrements the count;
-     * otherwise invokes {@link #onCompletion} and then similarly
-     * tries to complete this task's completer, if one exists,
-     * else marks this task as complete.
+     * otherwise invokes {@link #onCompletion(CountedCompleter)}
+     * and then similarly tries to complete this task's completer,
+     * if one exists, else marks this task as complete.
      */
     public final void tryComplete() {
         CountedCompleter a = this, s = a;
@@ -556,12 +559,12 @@ public abstract class CountedCompleter extends ForkJoinTask {
 
     /**
      * Equivalent to {@link #tryComplete} but does not invoke {@link
-     * #onCompletion} along the completion path: If the pending count
-     * is nonzero, decrements the count; otherwise, similarly tries to
-     * complete this task's completer, if one exists, else marks this
-     * task as complete. This method may be useful in cases where
-     * {@code onCompletion} should not, or need not, be invoked for
-     * each completer in a computation.
+     * #onCompletion(CountedCompleter)} along the completion path:
+     * If the pending count is nonzero, decrements the count;
+     * otherwise, similarly tries to complete this task's completer, if
+     * one exists, else marks this task as complete. This method may be
+     * useful in cases where {@code onCompletion} should not, or need
+     * not, be invoked for each completer in a computation.
      */
     public final void propagateCompletion() {
         CountedCompleter a = this, s = a;
@@ -578,13 +581,15 @@ public abstract class CountedCompleter extends ForkJoinTask {
     }
 
     /**
-     * Regardless of pending count, invokes {@link #onCompletion},
-     * marks this task as complete and further triggers {@link
-     * #tryComplete} on this task's completer, if one exists.  The
-     * given rawResult is used as an argument to {@link #setRawResult}
-     * before invoking {@link #onCompletion} or marking this task as
-     * complete; its value is meaningful only for classes overriding
-     * {@code setRawResult}.
+     * Regardless of pending count, invokes
+     * {@link #onCompletion(CountedCompleter)}, marks this task as
+     * complete and further triggers {@link #tryComplete} on this
+     * task's completer, if one exists.  The given rawResult is
+     * used as an argument to {@link #setRawResult} before invoking
+     * {@link #onCompletion(CountedCompleter)} or marking this task
+     * as complete; its value is meaningful only for classes
+     * overriding {@code setRawResult}.  This method does not modify
+     * the pending count.
      *
      * 
This method may be useful when forcing completion as soon as
      * any one (versus all) of several subtask results are obtained.
@@ -624,8 +629,8 @@ public abstract class CountedCompleter extends ForkJoinTask {
     /**
      * If this task does not have a completer, invokes {@link
      * ForkJoinTask#quietlyComplete} and returns {@code null}.  Or, if
-     * this task's pending count is non-zero, decrements its pending
-     * count and returns {@code null}.  Otherwise, returns the
+     * the completer's pending count is non-zero, decrements that
+     * pending count and returns {@code null}.  Otherwise, returns the
      * completer.  This method can be used as part of a completion
      * traversal loop for homogeneous task hierarchies:
      *
@@ -667,8 +672,9 @@ public abstract class CountedCompleter extends ForkJoinTask {
     void internalPropagateException(Throwable ex) {
         CountedCompleter a = this, s = a;
         while (a.onExceptionalCompletion(ex, s) &&
-               (a = (s = a).completer) != null && a.status >= 0)
-            a.recordExceptionalCompletion(ex);
+               (a = (s = a).completer) != null && a.status >= 0 &&
+               a.recordExceptionalCompletion(ex) == EXCEPTIONAL)
+            ;
     }
 
     /**
diff --git a/src/main/java/jsr166e/ForkJoinPool.java b/src/main/java/jsr166e/ForkJoinPool.java
index c5b5fb54340..fdf1df50ade 100644
--- a/src/main/java/jsr166e/ForkJoinPool.java
+++ b/src/main/java/jsr166e/ForkJoinPool.java
@@ -6,6 +6,7 @@
 
 package jsr166e;
 
+import java.lang.Thread.UncaughtExceptionHandler;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -17,6 +18,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Future;
 import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.RunnableFuture;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -49,9 +51,9 @@ import java.util.concurrent.TimeUnit;
  * level; by default, equal to the number of available processors. The
  * pool attempts to maintain enough active (or available) threads by
  * dynamically adding, suspending, or resuming internal worker
- * threads, even if some tasks are stalled waiting to join
- * others. However, no such adjustments are guaranteed in the face of
- * blocked I/O or other unmanaged synchronization. The nested {@link
+ * threads, even if some tasks are stalled waiting to join others.
+ * However, no such adjustments are guaranteed in the face of blocked
+ * I/O or other unmanaged synchronization. The nested {@link
  * ManagedBlocker} interface enables extension of the kinds of
  * synchronization accommodated.
  *
@@ -75,38 +77,45 @@ import java.util.concurrent.TimeUnit;
  * there is little difference among choice of methods.
  *
  * 
+ * 
  *  
  *    
  *    
  *    
  *  
  *  
- *    
+ *    
  *    
  *    
  *  
  *  
- *    
+ *    
  *    
  *    
  *  
  *  
- *    
+ *    
  *    
  *    
  *  
  * 
Summary of task execution methods
 Call from non-fork/join clients Call from within fork/join computations
 Arrange async execution Arrange async execution {@link #execute(ForkJoinTask)} {@link ForkJoinTask#fork}
 Await and obtain result Await and obtain result {@link #invoke(ForkJoinTask)} {@link ForkJoinTask#invoke}
 Arrange exec and obtain Future Arrange exec and obtain Future {@link #submit(ForkJoinTask)} {@link ForkJoinTask#fork} (ForkJoinTasks are Futures)

  *
  * 
The common pool is by default constructed with default
- * parameters, but these may be controlled by setting three {@link
- * System#getProperty system properties} with prefix {@code
- * java.util.concurrent.ForkJoinPool.common}: {@code parallelism} --
- * an integer greater than zero, {@code threadFactory} -- the class
- * name of a {@link ForkJoinWorkerThreadFactory}, and {@code
- * exceptionHandler} -- the class name of a {@link
- * java.lang.Thread.UncaughtExceptionHandler
- * Thread.UncaughtExceptionHandler}. Upon any error in establishing
- * these settings, default parameters are used.
+ * parameters, but these may be controlled by setting three
+ * {@linkplain System#getProperty system properties}:
+ * 
    
+ * 
  • {@code java.util.concurrent.ForkJoinPool.common.parallelism}
+ * - the parallelism level, a non-negative integer
+ * 
  • {@code java.util.concurrent.ForkJoinPool.common.threadFactory}
+ * - the class name of a {@link ForkJoinWorkerThreadFactory}
+ * 
  • {@code java.util.concurrent.ForkJoinPool.common.exceptionHandler}
+ * - the class name of a {@link UncaughtExceptionHandler}
+ * 

+ * The system class loader is used to load these classes.
+ * Upon any error in establishing these settings, default parameters
+ * are used. It is possible to disable or limit the use of threads in
+ * the common pool by setting the parallelism property to zero, and/or
+ * using a factory that may return {@code null}.
  *
  * 
Implementation notes: This implementation restricts the
  * maximum number of running threads to 32767. Attempts to create
@@ -152,32 +161,35 @@ public class ForkJoinPool extends AbstractExecutorService {
      * (http://research.sun.com/scalable/pubs/index.html) and
      * "Idempotent work stealing" by Michael, Saraswat, and Vechev,
      * PPoPP 2009 (http://portal.acm.org/citation.cfm?id=1504186).
-     * The main differences ultimately stem from GC requirements that
-     * we null out taken slots as soon as we can, to maintain as small
-     * a footprint as possible even in programs generating huge
-     * numbers of tasks. To accomplish this, we shift the CAS
-     * arbitrating pop vs poll (steal) from being on the indices
-     * ("base" and "top") to the slots themselves.  So, both a
-     * successful pop and poll mainly entail a CAS of a slot from
-     * non-null to null.  Because we rely on CASes of references, we
-     * do not need tag bits on base or top.  They are simple ints as
-     * used in any circular array-based queue (see for example
-     * ArrayDeque).  Updates to the indices must still be ordered in a
-     * way that guarantees that top == base means the queue is empty,
-     * but otherwise may err on the side of possibly making the queue
-     * appear nonempty when a push, pop, or poll have not fully
-     * committed. Note that this means that the poll operation,
-     * considered individually, is not wait-free. One thief cannot
-     * successfully continue until another in-progress one (or, if
-     * previously empty, a push) completes.  However, in the
-     * aggregate, we ensure at least probabilistic non-blockingness.
-     * If an attempted steal fails, a thief always chooses a different
-     * random victim target to try next. So, in order for one thief to
-     * progress, it suffices for any in-progress poll or new push on
-     * any empty queue to complete. (This is why we normally use
-     * method pollAt and its variants that try once at the apparent
-     * base index, else consider alternative actions, rather than
-     * method poll.)
+     * See also "Correct and Efficient Work-Stealing for Weak Memory
+     * Models" by Le, Pop, Cohen, and Nardelli, PPoPP 2013
+     * (http://www.di.ens.fr/~zappa/readings/ppopp13.pdf) for an
+     * analysis of memory ordering (atomic, volatile etc) issues.  The
+     * main differences ultimately stem from GC requirements that we
+     * null out taken slots as soon as we can, to maintain as small a
+     * footprint as possible even in programs generating huge numbers
+     * of tasks. To accomplish this, we shift the CAS arbitrating pop
+     * vs poll (steal) from being on the indices ("base" and "top") to
+     * the slots themselves.  So, both a successful pop and poll
+     * mainly entail a CAS of a slot from non-null to null.  Because
+     * we rely on CASes of references, we do not need tag bits on base
+     * or top.  They are simple ints as used in any circular
+     * array-based queue (see for example ArrayDeque).  Updates to the
+     * indices must still be ordered in a way that guarantees that top
+     * == base means the queue is empty, but otherwise may err on the
+     * side of possibly making the queue appear nonempty when a push,
+     * pop, or poll have not fully committed. Note that this means
+     * that the poll operation, considered individually, is not
+     * wait-free. One thief cannot successfully continue until another
+     * in-progress one (or, if previously empty, a push) completes.
+     * However, in the aggregate, we ensure at least probabilistic
+     * non-blockingness.  If an attempted steal fails, a thief always
+     * chooses a different random victim target to try next. So, in
+     * order for one thief to progress, it suffices for any
+     * in-progress poll or new push on any empty queue to
+     * complete. (This is why we normally use method pollAt and its
+     * variants that try once at the apparent base index, else
+     * consider alternative actions, rather than method poll.)
      *
      * This approach also enables support of a user mode in which local
      * task processing is in FIFO, not LIFO order, simply by using
@@ -196,18 +208,18 @@ public class ForkJoinPool extends AbstractExecutorService {
      * for work-stealing (this would contaminate lifo/fifo
      * processing). Instead, we randomly associate submission queues
      * with submitting threads, using a form of hashing.  The
-     * ThreadLocal Submitter class contains a value initially used as
-     * a hash code for choosing existing queues, but may be randomly
-     * repositioned upon contention with other submitters.  In
-     * essence, submitters act like workers except that they are
-     * restricted to executing local tasks that they submitted (or in
-     * the case of CountedCompleters, others with the same root task).
-     * However, because most shared/external queue operations are more
-     * expensive than internal, and because, at steady state, external
-     * submitters will compete for CPU with workers, ForkJoinTask.join
-     * and related methods disable them from repeatedly helping to
-     * process tasks if all workers are active.  Insertion of tasks in
-     * shared mode requires a lock (mainly to protect in the case of
+     * Submitter probe value serves as a hash code for
+     * choosing existing queues, and may be randomly repositioned upon
+     * contention with other submitters.  In essence, submitters act
+     * like workers except that they are restricted to executing local
+     * tasks that they submitted (or in the case of CountedCompleters,
+     * others with the same root task).  However, because most
+     * shared/external queue operations are more expensive than
+     * internal, and because, at steady state, external submitters
+     * will compete for CPU with workers, ForkJoinTask.join and
+     * related methods disable them from repeatedly helping to process
+     * tasks if all workers are active.  Insertion of tasks in shared
+     * mode requires a lock (mainly to protect in the case of
      * resizing) but we use only a simple spinlock (using bits in
      * field qlock), because submitters encountering a busy queue move
      * on to try or create other queues -- they block only when
@@ -297,37 +309,35 @@ public class ForkJoinPool extends AbstractExecutorService {
      * has not yet entered the wait queue. We solve this by requiring
      * a full sweep of all workers (via repeated calls to method
      * scan()) both before and after a newly waiting worker is added
-     * to the wait queue. During a rescan, the worker might release
-     * some other queued worker rather than itself, which has the same
-     * net effect. Because enqueued workers may actually be rescanning
-     * rather than waiting, we set and clear the "parker" field of
-     * WorkQueues to reduce unnecessary calls to unpark.  (This
-     * requires a secondary recheck to avoid missed signals.)  Note
-     * the unusual conventions about Thread.interrupts surrounding
-     * parking and other blocking: Because interrupts are used solely
-     * to alert threads to check termination, which is checked anyway
-     * upon blocking, we clear status (using Thread.interrupted)
-     * before any call to park, so that park does not immediately
-     * return due to status being set via some other unrelated call to
-     * interrupt in user code.
+     * to the wait queue.  Because enqueued workers may actually be
+     * rescanning rather than waiting, we set and clear the "parker"
+     * field of WorkQueues to reduce unnecessary calls to unpark.
+     * (This requires a secondary recheck to avoid missed signals.)
+     * Note the unusual conventions about Thread.interrupts
+     * surrounding parking and other blocking: Because interrupts are
+     * used solely to alert threads to check termination, which is
+     * checked anyway upon blocking, we clear status (using
+     * Thread.interrupted) before any call to park, so that park does
+     * not immediately return due to status being set via some other
+     * unrelated call to interrupt in user code.
      *
      * Signalling.  We create or wake up workers only when there
      * appears to be at least one task they might be able to find and
-     * execute. However, many other threads may notice the same task
-     * and each signal to wake up a thread that might take it. So in
-     * general, pools will be over-signalled.  When a submission is
-     * added or another worker adds a task to a queue that has fewer
-     * than two tasks, they signal waiting workers (or trigger
-     * creation of new ones if fewer than the given parallelism level
-     * -- signalWork), and may leave a hint to the unparked worker to
-     * help signal others upon wakeup).  These primary signals are
-     * buttressed by others (see method helpSignal) whenever other
-     * threads scan for work or do not have a task to process.  On
-     * most platforms, signalling (unpark) overhead time is noticeably
+     * execute.  When a submission is added or another worker adds a
+     * task to a queue that has fewer than two tasks, they signal
+     * waiting workers (or trigger creation of new ones if fewer than
+     * the given parallelism level -- signalWork).  These primary
+     * signals are buttressed by others whenever other threads remove
+     * a task from a queue and notice that there are other tasks there
+     * as well.  So in general, pools will be over-signalled. On most
+     * platforms, signalling (unpark) overhead time is noticeably
      * long, and the time between signalling a thread and it actually
      * making progress can be very noticeably long, so it is worth
      * offloading these delays from critical paths as much as
-     * possible.
+     * possible. Additionally, workers spin-down gradually, by staying
+     * alive so long as they see the ctl state changing.  Similar
+     * stability-sensing techniques are also used before blocking in
+     * awaitJoin and helpComplete.
      *
      * Trimming workers. To release resources after periods of lack of
      * use, a worker starting to wait when the pool is quiescent will
@@ -440,7 +450,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * Common Pool
      * ===========
      *
-     * The static common Pool always exists after static
+     * The static common pool always exists after static
      * initialization.  Since it (or any other created pool) need
      * never be used, we minimize initial construction overhead and
      * footprint to the setup of about a dozen fields, with no nested
@@ -448,8 +458,11 @@ public class ForkJoinPool extends AbstractExecutorService {
      * fullExternalPush during the first submission to the pool.
      *
      * When external threads submit to the common pool, they can
-     * perform some subtask processing (see externalHelpJoin and
-     * related methods).  We do not need to record whether these
+     * perform subtask processing (see externalHelpJoin and related
+     * methods).  This caller-helps policy makes it sensible to set
+     * common pool parallelism level to one (or more) less than the
+     * total number of available cores, or even zero for pure
+     * caller-runs.  We do not need to record whether external
      * submissions are to the common pool -- if not, externalHelpJoin
      * returns quickly (at the most helping to signal some common pool
      * workers). These submitters would otherwise be blocked waiting
@@ -519,6 +532,7 @@ public class ForkJoinPool extends AbstractExecutorService {
          *
          * @param pool the pool this thread works in
          * @throws NullPointerException if the pool is null
+         * @return the new worker thread
          */
         public ForkJoinWorkerThread newThread(ForkJoinPool pool);
     }
@@ -534,26 +548,6 @@ public class ForkJoinPool extends AbstractExecutorService {
         }
     }
 
-    /**
-     * Per-thread records for threads that submit to pools. Currently
-     * holds only pseudo-random seed / index that is used to choose
-     * submission queues in method externalPush. In the future, this may
-     * also incorporate a means to implement different task rejection
-     * and resubmission policies.
-     *
-     * Seeds for submitters and workers/workQueues work in basically
-     * the same way but are initialized and updated using slightly
-     * different mechanics. Both are initialized using the same
-     * approach as in class ThreadLocal, where successive values are
-     * unlikely to collide with previous values. Seeds are then
-     * randomly modified upon collisions using xorshifts, which
-     * requires a non-zero seed.
-     */
-    static final class Submitter {
-        int seed;
-        Submitter(int s) { seed = s; }
-    }
-
     /**
      * Class for artificial tasks that are used to replace the target
      * of local joins if they are removed from an interior queue slot
@@ -613,17 +607,8 @@ public class ForkJoinPool extends AbstractExecutorService {
      * do not want multiple WorkQueue instances or multiple queue
      * arrays sharing cache lines. (It would be best for queue objects
      * and their arrays to share, but there is nothing available to
-     * help arrange that).  Unfortunately, because they are recorded
-     * in a common array, WorkQueue instances are often moved to be
-     * adjacent by garbage collectors. To reduce impact, we use field
-     * padding that works OK on common platforms; this effectively
-     * trades off slightly slower average field access for the sake of
-     * avoiding really bad worst-case access. (Until better JVM
-     * support is in place, this padding is dependent on transient
-     * properties of JVM field layout rules.) We also take care in
-     * allocating, sizing and resizing the array. Non-shared queue
-     * arrays are initialized by workers before use. Others are
-     * allocated on first use.
+     * help arrange that). The @Contended annotation alerts JVMs to
+     * try to keep instances apart.
      */
     static final class WorkQueue {
         /**
@@ -649,13 +634,12 @@ public class ForkJoinPool extends AbstractExecutorService {
         // Heuristic padding to ameliorate unfortunate memory placements
         volatile long pad00, pad01, pad02, pad03, pad04, pad05, pad06;
 
-        int seed;                  // for random scanning; initialize nonzero
         volatile int eventCount;   // encoded inactivation count; < 0 if inactive
         int nextWait;              // encoded record of next event waiter
-        int hint;                  // steal or signal hint (index)
-        int poolIndex;             // index of this queue in pool (or 0)
-        final int mode;            // 0: lifo, > 0: fifo, < 0: shared
         int nsteals;               // number of steals
+        int hint;                  // steal index hint
+        short poolIndex;           // index of this queue in pool
+        final short mode;          // 0: lifo, > 0: fifo, < 0: shared
         volatile int qlock;        // 1: locked, -1: terminate; else 0
         volatile int base;         // index of next slot for poll
         int top;                   // index of next slot for push
@@ -673,8 +657,8 @@ public class ForkJoinPool extends AbstractExecutorService {
                   int seed) {
             this.pool = pool;
             this.owner = owner;
-            this.mode = mode;
-            this.seed = seed;
+            this.mode = (short)mode;
+            this.hint = seed; // store initial seed for runWorker
             // Place indices in the center of array (that is not yet allocated)
             base = top = INITIAL_QUEUE_CAPACITY >>> 1;
         }
@@ -687,7 +671,7 @@ public class ForkJoinPool extends AbstractExecutorService {
             return (n >= 0) ? 0 : -n; // ignore transient negative
         }
 
-       /**
+        /**
          * Provides a more accurate estimate of whether this queue has
          * any tasks than does queueSize, by checking whether a
          * near-empty queue has at least one unclaimed task.
@@ -712,20 +696,18 @@ public class ForkJoinPool extends AbstractExecutorService {
          */
         final void push(ForkJoinTask task) {
             ForkJoinTask[] a; ForkJoinPool p;
-            int s = top, m, n;
+            int s = top, n;
             if ((a = array) != null) {    // ignore if queue removed
-                int j = (((m = a.length - 1) & s) << ASHIFT) + ABASE;
-                U.putOrderedObject(a, j, task);
-                if ((n = (top = s + 1) - base) <= 2) {
-                    if ((p = pool) != null)
-                        p.signalWork(this);
-                }
+                int m = a.length - 1;
+                U.putOrderedObject(a, ((m & s) << ASHIFT) + ABASE, task);
+                if ((n = (top = s + 1) - base) <= 2)
+                    (p = pool).signalWork(p.workQueues, this);
                 else if (n >= m)
                     growArray();
             }
         }
 
-       /**
+        /**
          * Initializes or doubles the capacity of array. Call either
          * by owner or with lock held -- it is OK for base, but not
          * top, to move while resizings are in progress.
@@ -783,9 +765,8 @@ public class ForkJoinPool extends AbstractExecutorService {
             if ((a = array) != null) {
                 int j = (((a.length - 1) & b) << ASHIFT) + ABASE;
                 if ((t = (ForkJoinTask)U.getObjectVolatile(a, j)) != null &&
-                    base == b &&
-                    U.compareAndSwapObject(a, j, t, null)) {
-                    base = b + 1;
+                    base == b && U.compareAndSwapObject(a, j, t, null)) {
+                    U.putOrderedInt(this, QBASE, b + 1);
                     return t;
                 }
             }
@@ -801,9 +782,8 @@ public class ForkJoinPool extends AbstractExecutorService {
                 int j = (((a.length - 1) & b) << ASHIFT) + ABASE;
                 t = (ForkJoinTask)U.getObjectVolatile(a, j);
                 if (t != null) {
-                    if (base == b &&
-                        U.compareAndSwapObject(a, j, t, null)) {
-                        base = b + 1;
+                    if (U.compareAndSwapObject(a, j, t, null)) {
+                        U.putOrderedInt(this, QBASE, b + 1);
                         return t;
                     }
                 }
@@ -860,48 +840,45 @@ public class ForkJoinPool extends AbstractExecutorService {
                 ForkJoinTask.cancelIgnoringExceptions(t);
         }
 
-        /**
-         * Computes next value for random probes.  Scans don't require
-         * a very high quality generator, but also not a crummy one.
-         * Marsaglia xor-shift is cheap and works well enough.  Note:
-         * This is manually inlined in its usages in ForkJoinPool to
-         * avoid writes inside busy scan loops.
-         */
-        final int nextSeed() {
-            int r = seed;
-            r ^= r << 13;
-            r ^= r >>> 17;
-            return seed = r ^= r << 5;
-        }
-
         // Specialized execution methods
 
-        /**
-         * Pops and runs tasks until empty.
-         */
-        private void popAndExecAll() {
-            // A bit faster than repeated pop calls
-            ForkJoinTask[] a; int m, s; long j; ForkJoinTask t;
-            while ((a = array) != null && (m = a.length - 1) >= 0 &&
-                   (s = top - 1) - base >= 0 &&
-                   (t = ((ForkJoinTask)
-                         U.getObject(a, j = ((m & s) << ASHIFT) + ABASE)))
-                   != null) {
-                if (U.compareAndSwapObject(a, j, t, null)) {
-                    top = s;
-                    t.doExec();
-                }
-            }
-        }
-
         /**
          * Polls and runs tasks until empty.
          */
-        private void pollAndExecAll() {
+        final void pollAndExecAll() {
             for (ForkJoinTask t; (t = poll()) != null;)
                 t.doExec();
         }
 
+        /**
+         * Executes a top-level task and any local tasks remaining
+         * after execution.
+         */
+        final void runTask(ForkJoinTask task) {
+            if ((currentSteal = task) != null) {
+                task.doExec();
+                ForkJoinTask[] a = array;
+                int md = mode;
+                ++nsteals;
+                currentSteal = null;
+                if (md != 0)
+                    pollAndExecAll();
+                else if (a != null) {
+                    int s, m = a.length - 1;
+                    while ((s = top - 1) - base >= 0) {
+                        long i = ((m & s) << ASHIFT) + ABASE;
+                        ForkJoinTask t = (ForkJoinTask)U.getObject(a, i);
+                        if (t == null)
+                            break;
+                        if (U.compareAndSwapObject(a, i, t, null)) {
+                            top = s;
+                            t.doExec();
+                        }
+                    }
+                }
+            }
+        }
+
         /**
          * If present, removes from queue and executes the given task,
          * or any other cancelled task. Returns (true) on any CAS
@@ -910,13 +887,15 @@ public class ForkJoinPool extends AbstractExecutorService {
          * @return false if no progress can be made, else true
          */
         final boolean tryRemoveAndExec(ForkJoinTask task) {
-            boolean stat = true, removed = false, empty = true;
+            boolean stat;
             ForkJoinTask[] a; int m, s, b, n;
-            if ((a = array) != null && (m = a.length - 1) >= 0 &&
+            if (task != null && (a = array) != null && (m = a.length - 1) >= 0 &&
                 (n = (s = top) - (b = base)) > 0) {
+                boolean removed = false, empty = true;
+                stat = true;
                 for (ForkJoinTask t;;) {           // traverse from s to b
-                    int j = ((--s & m) << ASHIFT) + ABASE;
-                    t = (ForkJoinTask)U.getObjectVolatile(a, j);
+                    long j = ((--s & m) << ASHIFT) + ABASE;
+                    t = (ForkJoinTask)U.getObject(a, j);
                     if (t == null)                    // inconsistent length
                         break;
                     else if (t == task) {
@@ -944,68 +923,95 @@ public class ForkJoinPool extends AbstractExecutorService {
                         break;
                     }
                 }
+                if (removed)
+                    task.doExec();
             }
-            if (removed)
-                task.doExec();
+            else
+                stat = false;
             return stat;
         }
 
         /**
-         * Polls for and executes the given task or any other task in
-         * its CountedCompleter computation.
+         * Tries to poll for and execute the given task or any other
+         * task in its CountedCompleter computation.
          */
-        final boolean pollAndExecCC(ForkJoinTask root) {
-            ForkJoinTask[] a; int b; Object o;
-            outer: while ((b = base) - top < 0 && (a = array) != null) {
+        final boolean pollAndExecCC(CountedCompleter root) {
+            ForkJoinTask[] a; int b; Object o; CountedCompleter t, r;
+            if ((b = base) - top < 0 && (a = array) != null) {
                 long j = (((a.length - 1) & b) << ASHIFT) + ABASE;
-                if ((o = U.getObject(a, j)) == null ||
-                    !(o instanceof CountedCompleter))
-                    break;
-                for (CountedCompleter t = (CountedCompleter)o, r = t;;) {
-                    if (r == root) {
-                        if (base == b &&
-                            U.compareAndSwapObject(a, j, t, null)) {
-                            base = b + 1;
-                            t.doExec();
+                if ((o = U.getObjectVolatile(a, j)) == null)
+                    return true; // retry
+                if (o instanceof CountedCompleter) {
+                    for (t = (CountedCompleter)o, r = t;;) {
+                        if (r == root) {
+                            if (base == b &&
+                                U.compareAndSwapObject(a, j, t, null)) {
+                                U.putOrderedInt(this, QBASE, b + 1);
+                                t.doExec();
+                            }
                             return true;
                         }
-                        else
-                            break; // restart
+                        else if ((r = r.completer) == null)
+                            break; // not part of root computation
                     }
-                    if ((r = r.completer) == null)
-                        break outer; // not part of root computation
                 }
             }
             return false;
         }
 
         /**
-         * Executes a top-level task and any local tasks remaining
-         * after execution.
+         * Tries to pop and execute the given task or any other task
+         * in its CountedCompleter computation.
          */
-        final void runTask(ForkJoinTask t) {
-            if (t != null) {
-                (currentSteal = t).doExec();
-                currentSteal = null;
-                ++nsteals;
-                if (base - top < 0) {       // process remaining local tasks
-                    if (mode == 0)
-                        popAndExecAll();
-                    else
-                        pollAndExecAll();
+        final boolean externalPopAndExecCC(CountedCompleter root) {
+            ForkJoinTask[] a; int s; Object o; CountedCompleter t, r;
+            if (base - (s = top) < 0 && (a = array) != null) {
+                long j = (((a.length - 1) & (s - 1)) << ASHIFT) + ABASE;
+                if ((o = U.getObject(a, j)) instanceof CountedCompleter) {
+                    for (t = (CountedCompleter)o, r = t;;) {
+                        if (r == root) {
+                            if (U.compareAndSwapInt(this, QLOCK, 0, 1)) {
+                                if (top == s && array == a &&
+                                    U.compareAndSwapObject(a, j, t, null)) {
+                                    top = s - 1;
+                                    qlock = 0;
+                                    t.doExec();
+                                }
+                                else
+                                    qlock = 0;
+                            }
+                            return true;
+                        }
+                        else if ((r = r.completer) == null)
+                            break;
+                    }
                 }
             }
+            return false;
         }
 
         /**
-         * Executes a non-top-level (stolen) task.
+         * Internal version
          */
-        final void runSubtask(ForkJoinTask t) {
-            if (t != null) {
-                ForkJoinTask ps = currentSteal;
-                (currentSteal = t).doExec();
-                currentSteal = ps;
+        final boolean internalPopAndExecCC(CountedCompleter root) {
+            ForkJoinTask[] a; int s; Object o; CountedCompleter t, r;
+            if (base - (s = top) < 0 && (a = array) != null) {
+                long j = (((a.length - 1) & (s - 1)) << ASHIFT) + ABASE;
+                if ((o = U.getObject(a, j)) instanceof CountedCompleter) {
+                    for (t = (CountedCompleter)o, r = t;;) {
+                        if (r == root) {
+                            if (U.compareAndSwapObject(a, j, t, null)) {
+                                top = s - 1;
+                                t.doExec();
+                            }
+                            return true;
+                        }
+                        else if ((r = r.completer) == null)
+                            break;
+                    }
+                }
             }
+            return false;
         }
 
         /**
@@ -1022,6 +1028,7 @@ public class ForkJoinPool extends AbstractExecutorService {
 
         // Unsafe mechanics
         private static final sun.misc.Unsafe U;
+        private static final long QBASE;
         private static final long QLOCK;
         private static final int ABASE;
         private static final int ASHIFT;
@@ -1030,6 +1037,8 @@ public class ForkJoinPool extends AbstractExecutorService {
                 U = getUnsafe();
                 Class k = WorkQueue.class;
                 Class ak = ForkJoinTask[].class;
+                QBASE = U.objectFieldOffset
+                    (k.getDeclaredField("base"));
                 QLOCK = U.objectFieldOffset
                     (k.getDeclaredField("qlock"));
                 ABASE = U.arrayBaseOffset(ak);
@@ -1045,13 +1054,6 @@ public class ForkJoinPool extends AbstractExecutorService {
 
     // static fields (initialized in static initializer below)
 
-    /**
-     * Creates a new ForkJoinWorkerThread. This factory is used unless
-     * overridden in ForkJoinPool constructors.
-     */
-    public static final ForkJoinWorkerThreadFactory
-        defaultForkJoinWorkerThreadFactory;
-
     /**
      * Per-thread submission bookkeeping. Shared across all pools
      * to reduce ThreadLocal pollution and because random motion
@@ -1061,6 +1063,13 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     static final ThreadLocal submitters;
 
+    /**
+     * Creates a new ForkJoinWorkerThread. This factory is used unless
+     * overridden in ForkJoinPool constructors.
+     */
+    public static final ForkJoinWorkerThreadFactory
+        defaultForkJoinWorkerThreadFactory;
+
     /**
      * Permission required for callers of methods that may start or
      * kill threads.
@@ -1076,7 +1085,10 @@ public class ForkJoinPool extends AbstractExecutorService {
     static final ForkJoinPool common;
 
     /**
-     * Common pool parallelism. Must equal common.parallelism.
+     * Common pool parallelism. To allow simpler use and management
+     * when common pool threads are disabled, we allow the underlying
+     * common.parallelism field to be zero, but in that case still report
+     * parallelism as 1 to reflect resulting caller-runs mechanics.
      */
     static final int commonParallelism;
 
@@ -1215,30 +1227,19 @@ public class ForkJoinPool extends AbstractExecutorService {
     static final int FIFO_QUEUE          =  1;
     static final int SHARED_QUEUE        = -1;
 
-    // bounds for #steps in scan loop -- must be power 2 minus 1
-    private static final int MIN_SCAN    = 0x1ff;   // cover estimation slop
-    private static final int MAX_SCAN    = 0x1ffff; // 4 * max workers
-
-    // Instance fields
-
-    /*
-     * Field layout of this class tends to matter more than one would
-     * like. Runtime layout order is only loosely related to
-     * declaration order and may differ across JVMs, but the following
-     * empirically works OK on current JVMs.
-     */
-
     // Heuristic padding to ameliorate unfortunate memory placements
     volatile long pad00, pad01, pad02, pad03, pad04, pad05, pad06;
 
+    // Instance fields
     volatile long stealCount;                  // collects worker counts
     volatile long ctl;                         // main pool control
     volatile int plock;                        // shutdown status and seqLock
     volatile int indexSeed;                    // worker/submitter index seed
-    final int config;                          // mode and parallelism level
+    final short parallelism;                   // parallelism level
+    final short mode;                          // LIFO/FIFO
     WorkQueue[] workQueues;                    // main registry
     final ForkJoinWorkerThreadFactory factory;
-    final Thread.UncaughtExceptionHandler ueh; // per-worker UEH
+    final UncaughtExceptionHandler ueh;        // per-worker UEH
     final String workerNamePrefix;             // to create worker name string
 
     volatile Object pad10, pad11, pad12, pad13, pad14, pad15, pad16, pad17;
@@ -1253,24 +1254,13 @@ public class ForkJoinPool extends AbstractExecutorService {
      * a more conservative alternative to a pure spinlock.
      */
     private int acquirePlock() {
-        int spins = PL_SPINS, r = 0, ps, nps;
+        int spins = PL_SPINS, ps, nps;
         for (;;) {
             if (((ps = plock) & PL_LOCK) == 0 &&
                 U.compareAndSwapInt(this, PLOCK, ps, nps = ps + PL_LOCK))
                 return nps;
-            else if (r == 0) { // randomize spins if possible
-                Thread t = Thread.currentThread(); WorkQueue w; Submitter z;
-                if ((t instanceof ForkJoinWorkerThread) &&
-                    (w = ((ForkJoinWorkerThread)t).workQueue) != null)
-                    r = w.seed;
-                else if ((z = submitters.get()) != null)
-                    r = z.seed;
-                else
-                    r = 1;
-            }
             else if (spins >= 0) {
-                r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift
-                if (r >= 0)
+                if (ThreadLocalRandom.current().nextInt() >= 0)
                     --spins;
             }
             else if (U.compareAndSwapInt(this, PLOCK, ps, ps | PL_SIGNAL)) {
@@ -1306,11 +1296,11 @@ public class ForkJoinPool extends AbstractExecutorService {
      * parallelism level exist. Adjusts counts etc on failure.
      */
     private void tryAddWorker() {
-        long c; int u;
+        long c; int u, e;
         while ((u = (int)((c = ctl) >>> 32)) < 0 &&
-               (u & SHORT_SIGN) != 0 && (int)c == 0) {
-            long nc = (long)(((u + UTC_UNIT) & UTC_MASK) |
-                             ((u + UAC_UNIT) & UAC_MASK)) << 32;
+               (u & SHORT_SIGN) != 0 && (e = (int)c) >= 0) {
+            long nc = ((long)(((u + UTC_UNIT) & UTC_MASK) |
+                              ((u + UAC_UNIT) & UAC_MASK)) << 32) | (long)e;
             if (U.compareAndSwapLong(this, CTL, c, nc)) {
                 ForkJoinWorkerThreadFactory fac;
                 Throwable ex = null;
@@ -1321,8 +1311,8 @@ public class ForkJoinPool extends AbstractExecutorService {
                         wt.start();
                         break;
                     }
-                } catch (Throwable e) {
-                    ex = e;
+                } catch (Throwable rex) {
+                    ex = rex;
                 }
                 deregisterWorker(wt, ex);
                 break;
@@ -1343,14 +1333,14 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @return the worker's queue
      */
     final WorkQueue registerWorker(ForkJoinWorkerThread wt) {
-        Thread.UncaughtExceptionHandler handler; WorkQueue[] ws; int s, ps;
+        UncaughtExceptionHandler handler; WorkQueue[] ws; int s, ps;
         wt.setDaemon(true);
         if ((handler = ueh) != null)
             wt.setUncaughtExceptionHandler(handler);
         do {} while (!U.compareAndSwapInt(this, INDEXSEED, s = indexSeed,
                                           s += SEED_INCREMENT) ||
                      s == 0); // skip 0
-        WorkQueue w = new WorkQueue(this, wt, config >>> 16, s);
+        WorkQueue w = new WorkQueue(this, wt, mode, s);
         if (((ps = plock) & PL_LOCK) != 0 ||
             !U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
             ps = acquirePlock();
@@ -1370,14 +1360,15 @@ public class ForkJoinPool extends AbstractExecutorService {
                         }
                     }
                 }
-                w.eventCount = w.poolIndex = r; // volatile write orders
+                w.poolIndex = (short)r;
+                w.eventCount = r; // volatile write orders
                 ws[r] = w;
             }
         } finally {
             if (!U.compareAndSwapInt(this, PLOCK, ps, nps))
                 releasePlock(nps);
         }
-        wt.setName(workerNamePrefix.concat(Integer.toString(w.poolIndex)));
+        wt.setName(workerNamePrefix.concat(Integer.toString(w.poolIndex >>> 1)));
         return w;
     }
 
@@ -1387,17 +1378,17 @@ public class ForkJoinPool extends AbstractExecutorService {
      * array, and adjusts counts. If pool is shutting down, tries to
      * complete termination.
      *
-     * @param wt the worker thread or null if construction failed
+     * @param wt the worker thread, or null if construction failed
      * @param ex the exception causing failure, or null if none
      */
     final void deregisterWorker(ForkJoinWorkerThread wt, Throwable ex) {
         WorkQueue w = null;
         if (wt != null && (w = wt.workQueue) != null) {
-            int ps;
+            int ps; long sc;
             w.qlock = -1;                // ensure set
-            long ns = w.nsteals, sc;     // collect steal count
             do {} while (!U.compareAndSwapLong(this, STEALCOUNT,
-                                               sc = stealCount, sc + ns));
+                                               sc = stealCount,
+                                               sc + w.nsteals));
             if (((ps = plock) & PL_LOCK) != 0 ||
                 !U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
                 ps = acquirePlock();
@@ -1454,6 +1445,26 @@ public class ForkJoinPool extends AbstractExecutorService {
 
     // Submissions
 
+    /**
+     * Per-thread records for threads that submit to pools. Currently
+     * holds only pseudo-random seed / index that is used to choose
+     * submission queues in method externalPush. In the future, this may
+     * also incorporate a means to implement different task rejection
+     * and resubmission policies.
+     *
+     * Seeds for submitters and workers/workQueues work in basically
+     * the same way but are initialized and updated using slightly
+     * different mechanics. Both are initialized using the same
+     * approach as in class ThreadLocal, where successive values are
+     * unlikely to collide with previous values. Seeds are then
+     * randomly modified upon collisions using xorshifts, which
+     * requires a non-zero seed.
+     */
+    static final class Submitter {
+        int seed;
+        Submitter(int s) { seed = s; }
+    }
+
     /**
      * Unless shutting down, adds the given task to a submission queue
      * at submitter's current queue index (modulo submission
@@ -1463,19 +1474,21 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @param task the task. Caller must ensure non-null.
      */
     final void externalPush(ForkJoinTask task) {
-        WorkQueue[] ws; WorkQueue q; Submitter z; int m; ForkJoinTask[] a;
-        if ((z = submitters.get()) != null && plock > 0 &&
-            (ws = workQueues) != null && (m = (ws.length - 1)) >= 0 &&
-            (q = ws[m & z.seed & SQMASK]) != null &&
+        Submitter z = submitters.get();
+        WorkQueue q; int r, m, s, n, am; ForkJoinTask[] a;
+        int ps = plock;
+        WorkQueue[] ws = workQueues;
+        if (z != null && ps > 0 && ws != null && (m = (ws.length - 1)) >= 0 &&
+            (q = ws[m & (r = z.seed) & SQMASK]) != null && r != 0 &&
             U.compareAndSwapInt(q, QLOCK, 0, 1)) { // lock
-            int b = q.base, s = q.top, n, an;
-            if ((a = q.array) != null && (an = a.length) > (n = s + 1 - b)) {
-                int j = (((an - 1) & s) << ASHIFT) + ABASE;
+            if ((a = q.array) != null &&
+                (am = a.length - 1) > (n = (s = q.top) - q.base)) {
+                int j = ((am & s) << ASHIFT) + ABASE;
                 U.putOrderedObject(a, j, task);
                 q.top = s + 1;                     // push on to deque
                 q.qlock = 0;
-                if (n <= 2)
-                    signalWork(q);
+                if (n <= 1)
+                    signalWork(ws, q);
                 return;
             }
             q.qlock = 0;
@@ -1513,13 +1526,13 @@ public class ForkJoinPool extends AbstractExecutorService {
                 r = z.seed;
                 r ^= r << 13;                   // same xorshift as WorkQueues
                 r ^= r >>> 17;
-                z.seed = r ^ (r << 5);
+                z.seed = r ^= (r << 5);
             }
-            else if ((ps = plock) < 0)
+            if ((ps = plock) < 0)
                 throw new RejectedExecutionException();
             else if (ps == 0 || (ws = workQueues) == null ||
                      (m = ws.length - 1) < 0) { // initialize workQueues
-                int p = config & SMASK;         // find power of two table size
+                int p = parallelism;            // find power of two table size
                 int n = (p > 1) ? p - 1 : 1;    // ensure at least 2 slots
                 n |= n >>> 1; n |= n >>> 2;  n |= n >>> 4;
                 n |= n >>> 8; n |= n >>> 16; n = (n + 1) << 1;
@@ -1551,7 +1564,7 @@ public class ForkJoinPool extends AbstractExecutorService {
                         q.qlock = 0;  // unlock
                     }
                     if (submitted) {
-                        signalWork(q);
+                        signalWork(ws, q);
                         return;
                     }
                 }
@@ -1559,6 +1572,7 @@ public class ForkJoinPool extends AbstractExecutorService {
             }
             else if (((ps = plock) & PL_LOCK) == 0) { // create new queue
                 q = new WorkQueue(this, null, SHARED_QUEUE, r);
+                q.poolIndex = (short)k;
                 if (((ps = plock) & PL_LOCK) != 0 ||
                     !U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
                     ps = acquirePlock();
@@ -1569,7 +1583,7 @@ public class ForkJoinPool extends AbstractExecutorService {
                     releasePlock(nps);
             }
             else
-                r = 0; // try elsewhere while lock held
+                r = 0;
         }
     }
 
@@ -1580,41 +1594,42 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     final void incrementActiveCount() {
         long c;
-        do {} while (!U.compareAndSwapLong(this, CTL, c = ctl, c + AC_UNIT));
+        do {} while (!U.compareAndSwapLong
+                     (this, CTL, c = ctl, ((c & ~AC_MASK) |
+                                           ((c & AC_MASK) + AC_UNIT))));
     }
 
     /**
      * Tries to create or activate a worker if too few are active.
      *
-     * @param q the (non-null) queue holding tasks to be signalled
+     * @param ws the worker array to use to find signallees
+     * @param q if non-null, the queue holding tasks to be processed
      */
-    final void signalWork(WorkQueue q) {
-        int hint = q.poolIndex;
-        long c; int e, u, i, n; WorkQueue[] ws; WorkQueue w; Thread p;
-        while ((u = (int)((c = ctl) >>> 32)) < 0) {
-            if ((e = (int)c) > 0) {
-                if ((ws = workQueues) != null && ws.length > (i = e & SMASK) &&
-                    (w = ws[i]) != null && w.eventCount == (e | INT_SIGN)) {
-                    long nc = (((long)(w.nextWait & E_MASK)) |
-                               ((long)(u + UAC_UNIT) << 32));
-                    if (U.compareAndSwapLong(this, CTL, c, nc)) {
-                        w.hint = hint;
-                        w.eventCount = (e + E_SEQ) & E_MASK;
-                        if ((p = w.parker) != null)
-                            U.unpark(p);
-                        break;
-                    }
-                    if (q.top - q.base <= 0)
-                        break;
-                }
-                else
-                    break;
-            }
-            else {
+    final void signalWork(WorkQueue[] ws, WorkQueue q) {
+        for (;;) {
+            long c; int e, u, i; WorkQueue w; Thread p;
+            if ((u = (int)((c = ctl) >>> 32)) >= 0)
+                break;
+            if ((e = (int)c) <= 0) {
                 if ((short)u < 0)
                     tryAddWorker();
                 break;
             }
+            if (ws == null || ws.length <= (i = e & SMASK) ||
+                (w = ws[i]) == null)
+                break;
+            long nc = (((long)(w.nextWait & E_MASK)) |
+                       ((long)(u + UAC_UNIT)) << 32);
+            int ne = (e + E_SEQ) & E_MASK;
+            if (w.eventCount == (e | INT_SIGN) &&
+                U.compareAndSwapLong(this, CTL, c, nc)) {
+                w.eventCount = ne;
+                if ((p = w.parker) != null)
+                    U.unpark(p);
+                break;
+            }
+            if (q != null && q.base >= q.top)
+                break;
         }
     }
 
@@ -1625,215 +1640,154 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     final void runWorker(WorkQueue w) {
         w.growArray(); // allocate queue
-        do { w.runTask(scan(w)); } while (w.qlock >= 0);
+        for (int r = w.hint; scan(w, r) == 0; ) {
+            r ^= r << 13; r ^= r >>> 17; r ^= r << 5; // xorshift
+        }
     }
 
     /**
-     * Scans for and, if found, returns one task, else possibly
+     * Scans for and, if found, runs one task, else possibly
      * inactivates the worker. This method operates on single reads of
      * volatile state and is designed to be re-invoked continuously,
      * in part because it returns upon detecting inconsistencies,
      * contention, or state changes that indicate possible success on
      * re-invocation.
      *
-     * The scan searches for tasks across queues (starting at a random
-     * index, and relying on registerWorker to irregularly scatter
-     * them within array to avoid bias), checking each at least twice.
-     * The scan terminates upon either finding a non-empty queue, or
-     * completing the sweep. If the worker is not inactivated, it
-     * takes and returns a task from this queue. Otherwise, if not
-     * activated, it signals workers (that may include itself) and
-     * returns so caller can retry. Also returns for true if the
-     * worker array may have changed during an empty scan.  On failure
-     * to find a task, we take one of the following actions, after
-     * which the caller will retry calling this method unless
-     * terminated.
-     *
-     * * If pool is terminating, terminate the worker.
-     *
-     * * If not already enqueued, try to inactivate and enqueue the
-     * worker on wait queue. Or, if inactivating has caused the pool
-     * to be quiescent, relay to idleAwaitWork to possibly shrink
-     * pool.
-     *
-     * * If already enqueued and none of the above apply, possibly
-     * park awaiting signal, else lingering to help scan and signal.
-     *
-     * * If a non-empty queue discovered or left as a hint,
-     * help wake up other workers before return.
+     * The scan searches for tasks across queues starting at a random
+     * index, checking each at least twice.  The scan terminates upon
+     * either finding a non-empty queue, or completing the sweep. If
+     * the worker is not inactivated, it takes and runs a task from
+     * this queue. Otherwise, if not activated, it tries to activate
+     * itself or some other worker by signalling. On failure to find a
+     * task, returns (for retry) if pool state may have changed during
+     * an empty scan, or tries to inactivate if active, else possibly
+     * blocks or terminates via method awaitWork.
      *
      * @param w the worker (via its WorkQueue)
-     * @return a task or null if none found
+     * @param r a random seed
+     * @return worker qlock status if would have waited, else 0
      */
-    private final ForkJoinTask scan(WorkQueue w) {
+    private final int scan(WorkQueue w, int r) {
         WorkQueue[] ws; int m;
-        int ps = plock;                          // read plock before ws
-        if (w != null && (ws = workQueues) != null && (m = ws.length - 1) >= 0) {
-            int ec = w.eventCount;               // ec is negative if inactive
-            int r = w.seed; r ^= r << 13; r ^= r >>> 17; w.seed = r ^= r << 5;
-            w.hint = -1;                         // update seed and clear hint
-            int j = ((m + m + 1) | MIN_SCAN) & MAX_SCAN;
-            do {
-                WorkQueue q; ForkJoinTask[] a; int b;
-                if ((q = ws[(r + j) & m]) != null && (b = q.base) - q.top < 0 &&
-                    (a = q.array) != null) {     // probably nonempty
-                    int i = (((a.length - 1) & b) << ASHIFT) + ABASE;
-                    ForkJoinTask t = (ForkJoinTask)
-                        U.getObjectVolatile(a, i);
-                    if (q.base == b && ec >= 0 && t != null &&
-                        U.compareAndSwapObject(a, i, t, null)) {
-                        if ((q.base = b + 1) - q.top < 0)
-                            signalWork(q);
-                        return t;                // taken
-                    }
-                    else if ((ec < 0 || j < m) && (int)(ctl >> AC_SHIFT) <= 0) {
-                        w.hint = (r + j) & m;    // help signal below
-                        break;                   // cannot take
+        long c = ctl;                            // for consistency check
+        if ((ws = workQueues) != null && (m = ws.length - 1) >= 0 && w != null) {
+            for (int j = m + m + 1, ec = w.eventCount;;) {
+                WorkQueue q; int b, e; ForkJoinTask[] a; ForkJoinTask t;
+                if ((q = ws[(r - j) & m]) != null &&
+                    (b = q.base) - q.top < 0 && (a = q.array) != null) {
+                    long i = (((a.length - 1) & b) << ASHIFT) + ABASE;
+                    if ((t = ((ForkJoinTask)
+                              U.getObjectVolatile(a, i))) != null) {
+                        if (ec < 0)
+                            helpRelease(c, ws, w, q, b);
+                        else if (q.base == b &&
+                                 U.compareAndSwapObject(a, i, t, null)) {
+                            U.putOrderedInt(q, QBASE, b + 1);
+                            if ((b + 1) - q.top < 0)
+                                signalWork(ws, q);
+                            w.runTask(t);
+                        }
                     }
+                    break;
                 }
-            } while (--j >= 0);
-
-            int h, e, ns; long c, sc; WorkQueue q;
-            if ((ns = w.nsteals) != 0) {
-                if (U.compareAndSwapLong(this, STEALCOUNT,
-                                         sc = stealCount, sc + ns))
-                    w.nsteals = 0;               // collect steals and rescan
-            }
-            else if (plock != ps)                // consistency check
-                ;                                // skip
-            else if ((e = (int)(c = ctl)) < 0)
-                w.qlock = -1;                    // pool is terminating
-            else {
-                if ((h = w.hint) < 0) {
-                    if (ec >= 0) {               // try to enqueue/inactivate
-                        long nc = (((long)ec |
-                                    ((c - AC_UNIT) & (AC_MASK|TC_MASK))));
-                        w.nextWait = e;          // link and mark inactive
+                else if (--j < 0) {
+                    if ((ec | (e = (int)c)) < 0) // inactive or terminating
+                        return awaitWork(w, c, ec);
+                    else if (ctl == c) {         // try to inactivate and enqueue
+                        long nc = (long)ec | ((c - AC_UNIT) & (AC_MASK|TC_MASK));
+                        w.nextWait = e;
                         w.eventCount = ec | INT_SIGN;
-                        if (ctl != c || !U.compareAndSwapLong(this, CTL, c, nc))
-                            w.eventCount = ec;   // unmark on CAS failure
-                        else if ((int)(c >> AC_SHIFT) == 1 - (config & SMASK))
-                            idleAwaitWork(w, nc, c);
-                    }
-                    else if (w.eventCount < 0 && ctl == c) {
-                        Thread wt = Thread.currentThread();
-                        Thread.interrupted();    // clear status
-                        U.putObject(wt, PARKBLOCKER, this);
-                        w.parker = wt;           // emulate LockSupport.park
-                        if (w.eventCount < 0)    // recheck
-                            U.park(false, 0L);   // block
-                        w.parker = null;
-                        U.putObject(wt, PARKBLOCKER, null);
-                    }
-                }
-                if ((h >= 0 || (h = w.hint) >= 0) &&
-                    (ws = workQueues) != null && h < ws.length &&
-                    (q = ws[h]) != null) {      // signal others before retry
-                    WorkQueue v; Thread p; int u, i, s;
-                    for (int n = (config & SMASK) - 1;;) {
-                        int idleCount = (w.eventCount < 0) ? 0 : -1;
-                        if (((s = idleCount - q.base + q.top) <= n &&
-                             (n = s) <= 0) ||
-                            (u = (int)((c = ctl) >>> 32)) >= 0 ||
-                            (e = (int)c) <= 0 || m < (i = e & SMASK) ||
-                            (v = ws[i]) == null)
-                            break;
-                        long nc = (((long)(v.nextWait & E_MASK)) |
-                                   ((long)(u + UAC_UNIT) << 32));
-                        if (v.eventCount != (e | INT_SIGN) ||
-                            !U.compareAndSwapLong(this, CTL, c, nc))
-                            break;
-                        v.hint = h;
-                        v.eventCount = (e + E_SEQ) & E_MASK;
-                        if ((p = v.parker) != null)
-                            U.unpark(p);
-                        if (--n <= 0)
-                            break;
+                        if (!U.compareAndSwapLong(this, CTL, c, nc))
+                            w.eventCount = ec;   // back out
                     }
+                    break;
                 }
             }
         }
-        return null;
+        return 0;
     }
 
     /**
-     * If inactivating worker w has caused the pool to become
-     * quiescent, checks for pool termination, and, so long as this is
-     * not the only worker, waits for event for up to a given
-     * duration.  On timeout, if ctl has not changed, terminates the
-     * worker, which will in turn wake up another worker to possibly
-     * repeat this process.
+     * A continuation of scan(), possibly blocking or terminating
+     * worker w. Returns without blocking if pool state has apparently
+     * changed since last invocation.  Also, if inactivating w has
+     * caused the pool to become quiescent, checks for pool
+     * termination, and, so long as this is not the only worker, waits
+     * for event for up to a given duration.  On timeout, if ctl has
+     * not changed, terminates the worker, which will in turn wake up
+     * another worker to possibly repeat this process.
      *
      * @param w the calling worker
-     * @param currentCtl the ctl value triggering possible quiescence
-     * @param prevCtl the ctl value to restore if thread is terminated
+     * @param c the ctl value on entry to scan
+     * @param ec the worker's eventCount on entry to scan
      */
-    private void idleAwaitWork(WorkQueue w, long currentCtl, long prevCtl) {
-        if (w != null && w.eventCount < 0 &&
-            !tryTerminate(false, false) && (int)prevCtl != 0 &&
-            ctl == currentCtl) {
-            int dc = -(short)(currentCtl >>> TC_SHIFT);
-            long parkTime = dc < 0 ? FAST_IDLE_TIMEOUT: (dc + 1) * IDLE_TIMEOUT;
-            long deadline = System.nanoTime() + parkTime - TIMEOUT_SLOP;
-            Thread wt = Thread.currentThread();
-            while (ctl == currentCtl) {
-                Thread.interrupted();  // timed variant of version in scan()
-                U.putObject(wt, PARKBLOCKER, this);
-                w.parker = wt;
-                if (ctl == currentCtl)
-                    U.park(false, parkTime);
-                w.parker = null;
-                U.putObject(wt, PARKBLOCKER, null);
-                if (ctl != currentCtl)
-                    break;
-                if (deadline - System.nanoTime() <= 0L &&
-                    U.compareAndSwapLong(this, CTL, currentCtl, prevCtl)) {
-                    w.eventCount = (w.eventCount + E_SEQ) | E_MASK;
-                    w.hint = -1;
-                    w.qlock = -1;   // shrink
-                    break;
+    private final int awaitWork(WorkQueue w, long c, int ec) {
+        int stat, ns; long parkTime, deadline;
+        if ((stat = w.qlock) >= 0 && w.eventCount == ec && ctl == c &&
+            !Thread.interrupted()) {
+            int e = (int)c;
+            int u = (int)(c >>> 32);
+            int d = (u >> UAC_SHIFT) + parallelism; // active count
+
+            if (e < 0 || (d <= 0 && tryTerminate(false, false)))
+                stat = w.qlock = -1;          // pool is terminating
+            else if ((ns = w.nsteals) != 0) { // collect steals and retry
+                long sc;
+                w.nsteals = 0;
+                do {} while (!U.compareAndSwapLong(this, STEALCOUNT,
+                                                   sc = stealCount, sc + ns));
+            }
+            else {
+                long pc = ((d > 0 || ec != (e | INT_SIGN)) ? 0L :
+                           ((long)(w.nextWait & E_MASK)) | // ctl to restore
+                           ((long)(u + UAC_UNIT)) << 32);
+                if (pc != 0L) {               // timed wait if last waiter
+                    int dc = -(short)(c >>> TC_SHIFT);
+                    parkTime = (dc < 0 ? FAST_IDLE_TIMEOUT:
+                                (dc + 1) * IDLE_TIMEOUT);
+                    deadline = System.nanoTime() + parkTime - TIMEOUT_SLOP;
+                }
+                else
+                    parkTime = deadline = 0L;
+                if (w.eventCount == ec && ctl == c) {
+                    Thread wt = Thread.currentThread();
+                    U.putObject(wt, PARKBLOCKER, this);
+                    w.parker = wt;            // emulate LockSupport.park
+                    if (w.eventCount == ec && ctl == c)
+                        U.park(false, parkTime);  // must recheck before park
+                    w.parker = null;
+                    U.putObject(wt, PARKBLOCKER, null);
+                    if (parkTime != 0L && ctl == c &&
+                        deadline - System.nanoTime() <= 0L &&
+                        U.compareAndSwapLong(this, CTL, c, pc))
+                        stat = w.qlock = -1;  // shrink pool
                 }
             }
         }
+        return stat;
     }
 
     /**
-     * Scans through queues looking for work while joining a task; if
-     * any present, signals. May return early if more signalling is
-     * detectably unneeded.
-     *
-     * @param task return early if done
-     * @param origin an index to start scan
+     * Possibly releases (signals) a worker. Called only from scan()
+     * when a worker with apparently inactive status finds a non-empty
+     * queue. This requires revalidating all of the associated state
+     * from caller.
      */
-    private void helpSignal(ForkJoinTask task, int origin) {
-        WorkQueue[] ws; WorkQueue w; Thread p; long c; int m, u, e, i, s;
-        if (task != null && task.status >= 0 &&
-            (u = (int)(ctl >>> 32)) < 0 && (u >> UAC_SHIFT) < 0 &&
-            (ws = workQueues) != null && (m = ws.length - 1) >= 0) {
-            outer: for (int k = origin, j = m; j >= 0; --j) {
-                WorkQueue q = ws[k++ & m];
-                for (int n = m;;) { // limit to at most m signals
-                    if (task.status < 0)
-                        break outer;
-                    if (q == null ||
-                        ((s = -q.base + q.top) <= n && (n = s) <= 0))
-                        break;
-                    if ((u = (int)((c = ctl) >>> 32)) >= 0 ||
-                        (e = (int)c) <= 0 || m < (i = e & SMASK) ||
-                        (w = ws[i]) == null)
-                        break outer;
-                    long nc = (((long)(w.nextWait & E_MASK)) |
-                               ((long)(u + UAC_UNIT) << 32));
-                    if (w.eventCount != (e | INT_SIGN))
-                        break outer;
-                    if (U.compareAndSwapLong(this, CTL, c, nc)) {
-                        w.eventCount = (e + E_SEQ) & E_MASK;
-                        if ((p = w.parker) != null)
-                            U.unpark(p);
-                        if (--n <= 0)
-                            break;
-                    }
-                }
+    private final void helpRelease(long c, WorkQueue[] ws, WorkQueue w,
+                                   WorkQueue q, int b) {
+        WorkQueue v; int e, i; Thread p;
+        if (w != null && w.eventCount < 0 && (e = (int)c) > 0 &&
+            ws != null && ws.length > (i = e & SMASK) &&
+            (v = ws[i]) != null && ctl == c) {
+            long nc = (((long)(v.nextWait & E_MASK)) |
+                       ((long)((int)(c >>> 32) + UAC_UNIT)) << 32);
+            int ne = (e + E_SEQ) & E_MASK;
+            if (q != null && q.base == b && w.eventCount < 0 &&
+                v.eventCount == (e | INT_SIGN) &&
+                U.compareAndSwapLong(this, CTL, c, nc)) {
+                v.eventCount = ne;
+                if ((p = v.parker) != null)
+                    U.unpark(p);
             }
         }
     }
@@ -1858,7 +1812,8 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     private int tryHelpStealer(WorkQueue joiner, ForkJoinTask task) {
         int stat = 0, steps = 0;                    // bound to avoid cycles
-        if (joiner != null && task != null) {       // hoist null checks
+        if (task != null && joiner != null &&
+            joiner.base - joiner.top >= 0) {        // hoist checks
             restart: for (;;) {
                 ForkJoinTask subtask = task;     // current target
                 for (WorkQueue j = joiner, v;;) {   // v is stealer of subtask
@@ -1885,7 +1840,7 @@ public class ForkJoinPool extends AbstractExecutorService {
                         }
                     }
                     for (;;) { // help stealer or descend to its stealer
-                        ForkJoinTask[] a;  int b;
+                        ForkJoinTask[] a; int b;
                         if (subtask.status < 0)     // surround probes with
                             continue restart;       //   consistency checks
                         if ((b = v.base) - v.top < 0 && (a = v.array) != null) {
@@ -1896,13 +1851,23 @@ public class ForkJoinPool extends AbstractExecutorService {
                                 v.currentSteal != subtask)
                                 continue restart;   // stale
                             stat = 1;               // apparent progress
-                            if (t != null && v.base == b &&
-                                U.compareAndSwapObject(a, i, t, null)) {
-                                v.base = b + 1;     // help stealer
-                                joiner.runSubtask(t);
+                            if (v.base == b) {
+                                if (t == null)
+                                    break restart;
+                                if (U.compareAndSwapObject(a, i, t, null)) {
+                                    U.putOrderedInt(v, QBASE, b + 1);
+                                    ForkJoinTask ps = joiner.currentSteal;
+                                    int jt = joiner.top;
+                                    do {
+                                        joiner.currentSteal = t;
+                                        t.doExec(); // clear local tasks too
+                                    } while (task.status >= 0 &&
+                                             joiner.top != jt &&
+                                             (t = joiner.pop()) != null);
+                                    joiner.currentSteal = ps;
+                                    break restart;
+                                }
                             }
-                            else if (v.base == b && ++steps == MAX_HELP)
-                                break restart;      // v apparently stalled
                         }
                         else {                      // empty -- try to descend
                             ForkJoinTask next = v.currentJoin;
@@ -1929,27 +1894,33 @@ public class ForkJoinPool extends AbstractExecutorService {
      * and run tasks within the target's computation.
      *
      * @param task the task to join
-     * @param mode if shared, exit upon completing any task
-     * if all workers are active
      */
-    private int helpComplete(ForkJoinTask task, int mode) {
-        WorkQueue[] ws; WorkQueue q; int m, n, s, u;
-        if (task != null && (ws = workQueues) != null &&
-            (m = ws.length - 1) >= 0) {
-            for (int j = 1, origin = j;;) {
+    private int helpComplete(WorkQueue joiner, CountedCompleter task) {
+        WorkQueue[] ws; int m;
+        int s = 0;
+        if ((ws = workQueues) != null && (m = ws.length - 1) >= 0 &&
+            joiner != null && task != null) {
+            int j = joiner.poolIndex;
+            int scans = m + m + 1;
+            long c = 0L;              // for stability check
+            for (int k = scans; ; j += 2) {
+                WorkQueue q;
                 if ((s = task.status) < 0)
-                    return s;
-                if ((q = ws[j & m]) != null && q.pollAndExecCC(task)) {
-                    origin = j;
-                    if (mode == SHARED_QUEUE &&
-                        ((u = (int)(ctl >>> 32)) >= 0 || (u >> UAC_SHIFT) >= 0))
-                        break;
-                }
-                else if ((j = (j + 2) & m) == origin)
                     break;
+                else if (joiner.internalPopAndExecCC(task))
+                    k = scans;
+                else if ((s = task.status) < 0)
+                    break;
+                else if ((q = ws[j & m]) != null && q.pollAndExecCC(task))
+                    k = scans;
+                else if (--k < 0) {
+                    if (c == (c = ctl))
+                        break;
+                    k = scans;
+                }
             }
         }
-        return 0;
+        return s;
     }
 
     /**
@@ -1958,17 +1929,22 @@ public class ForkJoinPool extends AbstractExecutorService {
      * for blocking. Fails on contention or termination. Otherwise,
      * adds a new thread if no idle workers are available and pool
      * may become starved.
+     *
+     * @param c the assumed ctl value
      */
-    final boolean tryCompensate() {
-        int pc = config & SMASK, e, i, tc; long c;
-        WorkQueue[] ws; WorkQueue w; Thread p;
-        if ((ws = workQueues) != null && (e = (int)(c = ctl)) >= 0) {
-            if (e != 0 && (i = e & SMASK) < ws.length &&
-                (w = ws[i]) != null && w.eventCount == (e | INT_SIGN)) {
+    final boolean tryCompensate(long c) {
+        WorkQueue[] ws = workQueues;
+        int pc = parallelism, e = (int)c, m, tc;
+        if (ws != null && (m = ws.length - 1) >= 0 && e >= 0 && ctl == c) {
+            WorkQueue w = ws[e & m];
+            if (e != 0 && w != null) {
+                Thread p;
                 long nc = ((long)(w.nextWait & E_MASK) |
                            (c & (AC_MASK|TC_MASK)));
-                if (U.compareAndSwapLong(this, CTL, c, nc)) {
-                    w.eventCount = (e + E_SEQ) & E_MASK;
+                int ne = (e + E_SEQ) & E_MASK;
+                if (w.eventCount == (e | INT_SIGN) &&
+                    U.compareAndSwapLong(this, CTL, c, nc)) {
+                    w.eventCount = ne;
                     if ((p = w.parker) != null)
                         U.unpark(p);
                     return true;   // replace with idle worker
@@ -2011,23 +1987,20 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     final int awaitJoin(WorkQueue joiner, ForkJoinTask task) {
         int s = 0;
-        if (joiner != null && task != null && (s = task.status) >= 0) {
+        if (task != null && (s = task.status) >= 0 && joiner != null) {
             ForkJoinTask prevJoin = joiner.currentJoin;
             joiner.currentJoin = task;
-            do {} while ((s = task.status) >= 0 && !joiner.isEmpty() &&
-                         joiner.tryRemoveAndExec(task)); // process local tasks
-            if (s >= 0 && (s = task.status) >= 0) {
-                helpSignal(task, joiner.poolIndex);
-                if ((s = task.status) >= 0 &&
-                    (task instanceof CountedCompleter))
-                    s = helpComplete(task, LIFO_QUEUE);
-            }
+            do {} while (joiner.tryRemoveAndExec(task) && // process local tasks
+                         (s = task.status) >= 0);
+            if (s >= 0 && (task instanceof CountedCompleter))
+                s = helpComplete(joiner, (CountedCompleter)task);
+            long cc = 0;        // for stability checks
             while (s >= 0 && (s = task.status) >= 0) {
-                if ((!joiner.isEmpty() ||           // try helping
-                     (s = tryHelpStealer(joiner, task)) == 0) &&
+                if ((s = tryHelpStealer(joiner, task)) == 0 &&
                     (s = task.status) >= 0) {
-                    helpSignal(task, joiner.poolIndex);
-                    if ((s = task.status) >= 0 && tryCompensate()) {
+                    if (!tryCompensate(cc))
+                        cc = ctl;
+                    else {
                         if (task.trySetSignal() && (s = task.status) >= 0) {
                             synchronized (task) {
                                 if (task.status >= 0) {
@@ -2040,9 +2013,11 @@ public class ForkJoinPool extends AbstractExecutorService {
                                     task.notifyAll();
                             }
                         }
-                        long c;                          // re-activate
+                        long c; // reactivate
                         do {} while (!U.compareAndSwapLong
-                                     (this, CTL, c = ctl, c + AC_UNIT));
+                                     (this, CTL, c = ctl,
+                                      ((c & ~AC_MASK) |
+                                       ((c & AC_MASK) + AC_UNIT))));
                     }
                 }
             }
@@ -2064,15 +2039,11 @@ public class ForkJoinPool extends AbstractExecutorService {
         if (joiner != null && task != null && (s = task.status) >= 0) {
             ForkJoinTask prevJoin = joiner.currentJoin;
             joiner.currentJoin = task;
-            do {} while ((s = task.status) >= 0 && !joiner.isEmpty() &&
-                         joiner.tryRemoveAndExec(task));
-            if (s >= 0 && (s = task.status) >= 0) {
-                helpSignal(task, joiner.poolIndex);
-                if ((s = task.status) >= 0 &&
-                    (task instanceof CountedCompleter))
-                    s = helpComplete(task, LIFO_QUEUE);
-            }
-            if (s >= 0 && joiner.isEmpty()) {
+            do {} while (joiner.tryRemoveAndExec(task) && // process local tasks
+                         (s = task.status) >= 0);
+            if (s >= 0) {
+                if (task instanceof CountedCompleter)
+                    helpComplete(joiner, (CountedCompleter)task);
                 do {} while (task.status >= 0 &&
                              tryHelpStealer(joiner, task) > 0);
             }
@@ -2084,14 +2055,14 @@ public class ForkJoinPool extends AbstractExecutorService {
      * Returns a (probably) non-empty steal queue, if one is found
      * during a scan, else null.  This method must be retried by
      * caller if, by the time it tries to use the queue, it is empty.
-     * @param r a (random) seed for scanning
      */
-    private WorkQueue findNonEmptyStealQueue(int r) {
+    private WorkQueue findNonEmptyStealQueue() {
+        int r = ThreadLocalRandom.current().nextInt();
         for (;;) {
             int ps = plock, m; WorkQueue[] ws; WorkQueue q;
             if ((ws = workQueues) != null && (m = ws.length - 1) >= 0) {
                 for (int j = (m + 1) << 2; j >= 0; --j) {
-                    if ((q = ws[(((r + j) << 1) | 1) & m]) != null &&
+                    if ((q = ws[(((r - j) << 1) | 1) & m]) != null &&
                         q.base - q.top < 0)
                         return q;
                 }
@@ -2108,35 +2079,36 @@ public class ForkJoinPool extends AbstractExecutorService {
      * find tasks either.
      */
     final void helpQuiescePool(WorkQueue w) {
+        ForkJoinTask ps = w.currentSteal;
         for (boolean active = true;;) {
             long c; WorkQueue q; ForkJoinTask t; int b;
-            while ((t = w.nextLocalTask()) != null) {
-                if (w.base - w.top < 0)
-                    signalWork(w);
+            while ((t = w.nextLocalTask()) != null)
                 t.doExec();
-            }
-            if ((q = findNonEmptyStealQueue(w.nextSeed())) != null) {
+            if ((q = findNonEmptyStealQueue()) != null) {
                 if (!active) {      // re-establish active count
                     active = true;
                     do {} while (!U.compareAndSwapLong
-                                 (this, CTL, c = ctl, c + AC_UNIT));
+                                 (this, CTL, c = ctl,
+                                  ((c & ~AC_MASK) |
+                                   ((c & AC_MASK) + AC_UNIT))));
                 }
                 if ((b = q.base) - q.top < 0 && (t = q.pollAt(b)) != null) {
-                    if (q.base - q.top < 0)
-                        signalWork(q);
-                    w.runSubtask(t);
+                    (w.currentSteal = t).doExec();
+                    w.currentSteal = ps;
                 }
             }
             else if (active) {       // decrement active count without queuing
-                long nc = (c = ctl) - AC_UNIT;
-                if ((int)(nc >> AC_SHIFT) + (config & SMASK) == 0)
-                    return;          // bypass decrement-then-increment
+                long nc = ((c = ctl) & ~AC_MASK) | ((c & AC_MASK) - AC_UNIT);
+                if ((int)(nc >> AC_SHIFT) + parallelism == 0)
+                    break;          // bypass decrement-then-increment
                 if (U.compareAndSwapLong(this, CTL, c, nc))
                     active = false;
             }
-            else if ((int)((c = ctl) >> AC_SHIFT) + (config & SMASK) == 0 &&
-                     U.compareAndSwapLong(this, CTL, c, c + AC_UNIT))
-                return;
+            else if ((int)((c = ctl) >> AC_SHIFT) + parallelism <= 0 &&
+                     U.compareAndSwapLong
+                     (this, CTL, c, ((c & ~AC_MASK) |
+                                     ((c & AC_MASK) + AC_UNIT))))
+                break;
         }
     }
 
@@ -2150,13 +2122,10 @@ public class ForkJoinPool extends AbstractExecutorService {
             WorkQueue q; int b;
             if ((t = w.nextLocalTask()) != null)
                 return t;
-            if ((q = findNonEmptyStealQueue(w.nextSeed())) == null)
+            if ((q = findNonEmptyStealQueue()) == null)
                 return null;
-            if ((b = q.base) - q.top < 0 && (t = q.pollAt(b)) != null) {
-                if (q.base - q.top < 0)
-                    signalWork(q);
+            if ((b = q.base) - q.top < 0 && (t = q.pollAt(b)) != null)
                 return t;
-            }
         }
     }
 
@@ -2209,7 +2178,7 @@ public class ForkJoinPool extends AbstractExecutorService {
     static int getSurplusQueuedTaskCount() {
         Thread t; ForkJoinWorkerThread wt; ForkJoinPool pool; WorkQueue q;
         if (((t = Thread.currentThread()) instanceof ForkJoinWorkerThread)) {
-            int p = (pool = (wt = (ForkJoinWorkerThread)t).pool).config & SMASK;
+            int p = (pool = (wt = (ForkJoinWorkerThread)t).pool).parallelism;
             int n = (q = wt.workQueue).top - q.base;
             int a = (int)(pool.ctl >> AC_SHIFT) + p;
             return n - (a > (p >>>= 1) ? 0 :
@@ -2239,7 +2208,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     private boolean tryTerminate(boolean now, boolean enable) {
         int ps;
-        if (this == common)                    // cannot shut down
+        if (this == common)                        // cannot shut down
             return false;
         if ((ps = plock) >= 0) {                   // enable by setting plock
             if (!enable)
@@ -2253,7 +2222,7 @@ public class ForkJoinPool extends AbstractExecutorService {
         }
         for (long c;;) {
             if (((c = ctl) & STOP_BIT) != 0) {     // already terminating
-                if ((short)(c >>> TC_SHIFT) == -(config & SMASK)) {
+                if ((short)(c >>> TC_SHIFT) + parallelism <= 0) {
                     synchronized (this) {
                         notifyAll();               // signal when 0 workers
                     }
@@ -2262,17 +2231,15 @@ public class ForkJoinPool extends AbstractExecutorService {
             }
             if (!now) {                            // check if idle & no tasks
                 WorkQueue[] ws; WorkQueue w;
-                if ((int)(c >> AC_SHIFT) != -(config & SMASK))
+                if ((int)(c >> AC_SHIFT) + parallelism > 0)
                     return false;
                 if ((ws = workQueues) != null) {
                     for (int i = 0; i < ws.length; ++i) {
-                        if ((w = ws[i]) != null) {
-                            if (!w.isEmpty()) {    // signal unprocessed tasks
-                                signalWork(w);
-                                return false;
-                            }
-                            if ((i & 1) != 0 && w.eventCount >= 0)
-                                return false;      // unqueued inactive worker
+                        if ((w = ws[i]) != null &&
+                            (!w.isEmpty() ||
+                             ((i & 1) != 0 && w.eventCount >= 0))) {
+                            signalWork(ws, w);
+                            return false;
                         }
                     }
                 }
@@ -2328,7 +2295,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * least one task.
      */
     static WorkQueue commonSubmitterQueue() {
-        ForkJoinPool p; WorkQueue[] ws; int m; Submitter z;
+        Submitter z; ForkJoinPool p; WorkQueue[] ws; int m, r;
         return ((z = submitters.get()) != null &&
                 (p = common) != null &&
                 (ws = p.workQueues) != null &&
@@ -2339,115 +2306,57 @@ public class ForkJoinPool extends AbstractExecutorService {
     /**
      * Tries to pop the given task from submitter's queue in common pool.
      */
-    static boolean tryExternalUnpush(ForkJoinTask t) {
-        ForkJoinPool p; WorkQueue[] ws; WorkQueue q; Submitter z;
-        ForkJoinTask[] a;  int m, s;
-        if (t != null &&
-            (z = submitters.get()) != null &&
-            (p = common) != null &&
-            (ws = p.workQueues) != null &&
-            (m = ws.length - 1) >= 0 &&
-            (q = ws[m & z.seed & SQMASK]) != null &&
-            (s = q.top) != q.base &&
-            (a = q.array) != null) {
+    final boolean tryExternalUnpush(ForkJoinTask task) {
+        WorkQueue joiner; ForkJoinTask[] a; int m, s;
+        Submitter z = submitters.get();
+        WorkQueue[] ws = workQueues;
+        boolean popped = false;
+        if (z != null && ws != null && (m = ws.length - 1) >= 0 &&
+            (joiner = ws[z.seed & m & SQMASK]) != null &&
+            joiner.base != (s = joiner.top) &&
+            (a = joiner.array) != null) {
             long j = (((a.length - 1) & (s - 1)) << ASHIFT) + ABASE;
-            if (U.getObject(a, j) == t &&
-                U.compareAndSwapInt(q, QLOCK, 0, 1)) {
-                if (q.array == a && q.top == s && // recheck
-                    U.compareAndSwapObject(a, j, t, null)) {
-                    q.top = s - 1;
-                    q.qlock = 0;
-                    return true;
+            if (U.getObject(a, j) == task &&
+                U.compareAndSwapInt(joiner, QLOCK, 0, 1)) {
+                if (joiner.top == s && joiner.array == a &&
+                    U.compareAndSwapObject(a, j, task, null)) {
+                    joiner.top = s - 1;
+                    popped = true;
                 }
-                q.qlock = 0;
+                joiner.qlock = 0;
             }
         }
-        return false;
+        return popped;
     }
 
-    /**
-     * Tries to pop and run local tasks within the same computation
-     * as the given root. On failure, tries to help complete from
-     * other queues via helpComplete.
-     */
-    private void externalHelpComplete(WorkQueue q, ForkJoinTask root) {
-        ForkJoinTask[] a; int m;
-        if (q != null && (a = q.array) != null && (m = (a.length - 1)) >= 0 &&
-            root != null && root.status >= 0) {
-            for (;;) {
-                int s, u; Object o; CountedCompleter task = null;
-                if ((s = q.top) - q.base > 0) {
-                    long j = ((m & (s - 1)) << ASHIFT) + ABASE;
-                    if ((o = U.getObject(a, j)) != null &&
-                        (o instanceof CountedCompleter)) {
-                        CountedCompleter t = (CountedCompleter)o, r = t;
-                        do {
-                            if (r == root) {
-                                if (U.compareAndSwapInt(q, QLOCK, 0, 1)) {
-                                    if (q.array == a && q.top == s &&
-                                        U.compareAndSwapObject(a, j, t, null)) {
-                                        q.top = s - 1;
-                                        task = t;
-                                    }
-                                    q.qlock = 0;
-                                }
-                                break;
-                            }
-                        } while ((r = r.completer) != null);
-                    }
-                }
-                if (task != null)
-                    task.doExec();
-                if (root.status < 0 ||
-                    (u = (int)(ctl >>> 32)) >= 0 || (u >> UAC_SHIFT) >= 0)
+    final int externalHelpComplete(CountedCompleter task) {
+        WorkQueue joiner; int m, j;
+        Submitter z = submitters.get();
+        WorkQueue[] ws = workQueues;
+        int s = 0;
+        if (z != null && ws != null && (m = ws.length - 1) >= 0 &&
+            (joiner = ws[(j = z.seed) & m & SQMASK]) != null && task != null) {
+            int scans = m + m + 1;
+            long c = 0L;             // for stability check
+            j |= 1;                  // poll odd queues
+            for (int k = scans; ; j += 2) {
+                WorkQueue q;
+                if ((s = task.status) < 0)
                     break;
-                if (task == null) {
-                    helpSignal(root, q.poolIndex);
-                    if (root.status >= 0)
-                        helpComplete(root, SHARED_QUEUE);
+                else if (joiner.externalPopAndExecCC(task))
+                    k = scans;
+                else if ((s = task.status) < 0)
                     break;
+                else if ((q = ws[j & m]) != null && q.pollAndExecCC(task))
+                    k = scans;
+                else if (--k < 0) {
+                    if (c == (c = ctl))
+                        break;
+                    k = scans;
                 }
             }
         }
-    }
-
-    /**
-     * Tries to help execute or signal availability of the given task
-     * from submitter's queue in common pool.
-     */
-    static void externalHelpJoin(ForkJoinTask t) {
-        // Some hard-to-avoid overlap with tryExternalUnpush
-        ForkJoinPool p; WorkQueue[] ws; WorkQueue q, w; Submitter z;
-        ForkJoinTask[] a;  int m, s, n;
-        if (t != null &&
-            (z = submitters.get()) != null &&
-            (p = common) != null &&
-            (ws = p.workQueues) != null &&
-            (m = ws.length - 1) >= 0 &&
-            (q = ws[m & z.seed & SQMASK]) != null &&
-            (a = q.array) != null) {
-            int am = a.length - 1;
-            if ((s = q.top) != q.base) {
-                long j = ((am & (s - 1)) << ASHIFT) + ABASE;
-                if (U.getObject(a, j) == t &&
-                    U.compareAndSwapInt(q, QLOCK, 0, 1)) {
-                    if (q.array == a && q.top == s &&
-                        U.compareAndSwapObject(a, j, t, null)) {
-                        q.top = s - 1;
-                        q.qlock = 0;
-                        t.doExec();
-                    }
-                    else
-                        q.qlock = 0;
-                }
-            }
-            if (t.status >= 0) {
-                if (t instanceof CountedCompleter)
-                    p.externalHelpComplete(q, t);
-                else
-                    p.helpSignal(t, q.poolIndex);
-            }
-        }
+        return s;
     }
 
     // Exported methods
@@ -2514,37 +2423,46 @@ public class ForkJoinPool extends AbstractExecutorService {
      */
     public ForkJoinPool(int parallelism,
                         ForkJoinWorkerThreadFactory factory,
-                        Thread.UncaughtExceptionHandler handler,
+                        UncaughtExceptionHandler handler,
                         boolean asyncMode) {
+        this(checkParallelism(parallelism),
+             checkFactory(factory),
+             handler,
+             (asyncMode ? FIFO_QUEUE : LIFO_QUEUE),
+             "ForkJoinPool-" + nextPoolId() + "-worker-");
         checkPermission();
-        if (factory == null)
-            throw new NullPointerException();
+    }
+
+    private static int checkParallelism(int parallelism) {
         if (parallelism <= 0 || parallelism > MAX_CAP)
             throw new IllegalArgumentException();
-        this.factory = factory;
-        this.ueh = handler;
-        this.config = parallelism | (asyncMode ? (FIFO_QUEUE << 16) : 0);
-        long np = (long)(-parallelism); // offset ctl counts
-        this.ctl = ((np << AC_SHIFT) & AC_MASK) | ((np << TC_SHIFT) & TC_MASK);
-        int pn = nextPoolId();
-        StringBuilder sb = new StringBuilder("ForkJoinPool-");
-        sb.append(Integer.toString(pn));
-        sb.append("-worker-");
-        this.workerNamePrefix = sb.toString();
+        return parallelism;
+    }
+
+    private static ForkJoinWorkerThreadFactory checkFactory
+        (ForkJoinWorkerThreadFactory factory) {
+        if (factory == null)
+            throw new NullPointerException();
+        return factory;
     }
 
     /**
-     * Constructor for common pool, suitable only for static initialization.
-     * Basically the same as above, but uses smallest possible initial footprint.
+     * Creates a {@code ForkJoinPool} with the given parameters, without
+     * any security checks or parameter validation.  Invoked directly by
+     * makeCommonPool.
      */
-    ForkJoinPool(int parallelism, long ctl,
-                 ForkJoinWorkerThreadFactory factory,
-                 Thread.UncaughtExceptionHandler handler) {
-        this.config = parallelism;
-        this.ctl = ctl;
+    private ForkJoinPool(int parallelism,
+                         ForkJoinWorkerThreadFactory factory,
+                         UncaughtExceptionHandler handler,
+                         int mode,
+                         String workerNamePrefix) {
+        this.workerNamePrefix = workerNamePrefix;
         this.factory = factory;
         this.ueh = handler;
-        this.workerNamePrefix = "ForkJoinPool.commonPool-worker-";
+        this.mode = (short)mode;
+        this.parallelism = (short)parallelism;
+        long np = (long)(-parallelism); // offset ctl counts
+        this.ctl = ((np << AC_SHIFT) & AC_MASK) | ((np << TC_SHIFT) & TC_MASK);
     }
 
     /**
@@ -2554,8 +2472,8 @@ public class ForkJoinPool extends AbstractExecutorService {
      * ongoing processing are automatically terminated upon program
      * {@link System#exit}.  Any program that relies on asynchronous
      * task processing to complete before program termination should
-     * invoke {@code commonPool().}{@link #awaitQuiescence}, before
-     * exit.
+     * invoke {@code commonPool().}{@link #awaitQuiescence awaitQuiescence},
+     * before exit.
      *
      * @return the common pool instance
      * @since 1.8
@@ -2618,7 +2536,7 @@ public class ForkJoinPool extends AbstractExecutorService {
         if (task instanceof ForkJoinTask) // avoid re-wrap
             job = (ForkJoinTask) task;
         else
-            job = new ForkJoinTask.AdaptedRunnableAction(task);
+            job = new ForkJoinTask.RunnableExecuteAction(task);
         externalPush(job);
     }
 
@@ -2720,7 +2638,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      *
      * @return the handler, or {@code null} if none
      */
-    public Thread.UncaughtExceptionHandler getUncaughtExceptionHandler() {
+    public UncaughtExceptionHandler getUncaughtExceptionHandler() {
         return ueh;
     }
 
@@ -2730,7 +2648,8 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @return the targeted parallelism level of this pool
      */
     public int getParallelism() {
-        return config & SMASK;
+        int par;
+        return ((par = parallelism) > 0) ? par : 1;
     }
 
     /**
@@ -2752,7 +2671,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @return the number of worker threads
      */
     public int getPoolSize() {
-        return (config & SMASK) + (short)(ctl >>> TC_SHIFT);
+        return parallelism + (short)(ctl >>> TC_SHIFT);
     }
 
     /**
@@ -2762,7 +2681,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @return {@code true} if this pool uses async mode
      */
     public boolean getAsyncMode() {
-        return (config >>> 16) == FIFO_QUEUE;
+        return mode == FIFO_QUEUE;
     }
 
     /**
@@ -2793,7 +2712,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @return the number of active threads
      */
     public int getActiveThreadCount() {
-        int r = (config & SMASK) + (int)(ctl >> AC_SHIFT);
+        int r = parallelism + (int)(ctl >> AC_SHIFT);
         return (r <= 0) ? 0 : r; // suppress momentarily negative values
     }
 
@@ -2809,7 +2728,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * @return {@code true} if all threads are currently idle
      */
     public boolean isQuiescent() {
-        return (int)(ctl >> AC_SHIFT) + (config & SMASK) == 0;
+        return parallelism + (int)(ctl >> AC_SHIFT) <= 0;
     }
 
     /**
@@ -2972,7 +2891,7 @@ public class ForkJoinPool extends AbstractExecutorService {
                 }
             }
         }
-        int pc = (config & SMASK);
+        int pc = parallelism;
         int tc = pc + (short)(c >>> TC_SHIFT);
         int ac = pc + (int)(c >> AC_SHIFT);
         if (ac < 0) // ignore transient negative
@@ -3045,7 +2964,7 @@ public class ForkJoinPool extends AbstractExecutorService {
     public boolean isTerminated() {
         long c = ctl;
         return ((c & STOP_BIT) != 0L &&
-                (short)(c >>> TC_SHIFT) == -(config & SMASK));
+                (short)(c >>> TC_SHIFT) + parallelism <= 0);
     }
 
     /**
@@ -3064,7 +2983,7 @@ public class ForkJoinPool extends AbstractExecutorService {
     public boolean isTerminating() {
         long c = ctl;
         return ((c & STOP_BIT) != 0L &&
-                (short)(c >>> TC_SHIFT) != -(config & SMASK));
+                (short)(c >>> TC_SHIFT) + parallelism > 0);
     }
 
     /**
@@ -3082,7 +3001,7 @@ public class ForkJoinPool extends AbstractExecutorService {
      * is interrupted, whichever happens first. Because the {@link
      * #commonPool()} never terminates until program shutdown, when
      * applied to the common pool, this method is equivalent to {@link
-     * #awaitQuiescence} but always returns {@code false}.
+     * #awaitQuiescence(long, TimeUnit)} but always returns {@code false}.
      *
      * @param timeout the maximum time to wait
      * @param unit the time unit of the timeout argument
@@ -3101,19 +3020,20 @@ public class ForkJoinPool extends AbstractExecutorService {
         long nanos = unit.toNanos(timeout);
         if (isTerminated())
             return true;
-        long startTime = System.nanoTime();
-        boolean terminated = false;
+        if (nanos <= 0L)
+            return false;
+        long deadline = System.nanoTime() + nanos;
         synchronized (this) {
-            for (long waitTime = nanos, millis = 0L;;) {
-                if (terminated = isTerminated() ||
-                    waitTime <= 0L ||
-                    (millis = unit.toMillis(waitTime)) <= 0L)
-                    break;
-                wait(millis);
-                waitTime = nanos - (System.nanoTime() - startTime);
+            for (;;) {
+                if (isTerminated())
+                    return true;
+                if (nanos <= 0L)
+                    return false;
+                long millis = TimeUnit.NANOSECONDS.toMillis(nanos);
+                wait(millis > 0L ? millis : 1L);
+                nanos = deadline - System.nanoTime();
             }
         }
-        return terminated;
     }
 
     /**
@@ -3152,11 +3072,8 @@ public class ForkJoinPool extends AbstractExecutorService {
                 ForkJoinTask t; WorkQueue q; int b;
                 if ((q = ws[r++ & m]) != null && (b = q.base) - q.top < 0) {
                     found = true;
-                    if ((t = q.pollAt(b)) != null) {
-                        if (q.base - q.top < 0)
-                            signalWork(q);
+                    if ((t = q.pollAt(b)) != null)
                         t.doExec();
-                    }
                     break;
                 }
             }
@@ -3181,9 +3098,9 @@ public class ForkJoinPool extends AbstractExecutorService {
      * not necessary. Method {@code block} blocks the current thread
      * if necessary (perhaps internally invoking {@code isReleasable}
      * before actually blocking). These actions are performed by any
-     * thread invoking {@link ForkJoinPool#managedBlock}.  The
-     * unusual methods in this API accommodate synchronizers that may,
-     * but don't usually, block for long periods. Similarly, they
+     * thread invoking {@link ForkJoinPool#managedBlock(ManagedBlocker)}.
+     * The unusual methods in this API accommodate synchronizers that
+     * may, but don't usually, block for long periods. Similarly, they
      * allow more efficient internal handling of cases in which
      * additional workers may be, but usually are not, needed to
      * ensure sufficient parallelism.  Toward this end,
@@ -3241,6 +3158,7 @@ public class ForkJoinPool extends AbstractExecutorService {
 
         /**
          * Returns {@code true} if blocking is unnecessary.
+         * @return {@code true} if blocking is unnecessary
          */
         boolean isReleasable();
     }
@@ -3270,21 +3188,8 @@ public class ForkJoinPool extends AbstractExecutorService {
         Thread t = Thread.currentThread();
         if (t instanceof ForkJoinWorkerThread) {
             ForkJoinPool p = ((ForkJoinWorkerThread)t).pool;
-            while (!blocker.isReleasable()) { // variant of helpSignal
-                WorkQueue[] ws; WorkQueue q; int m, u;
-                if ((ws = p.workQueues) != null && (m = ws.length - 1) >= 0) {
-                    for (int i = 0; i <= m; ++i) {
-                        if (blocker.isReleasable())
-                            return;
-                        if ((q = ws[i]) != null && q.base - q.top < 0) {
-                            p.signalWork(q);
-                            if ((u = (int)(p.ctl >>> 32)) >= 0 ||
-                                (u >> UAC_SHIFT) >= 0)
-                                break;
-                        }
-                    }
-                }
-                if (p.tryCompensate()) {
+            while (!blocker.isReleasable()) {
+                if (p.tryCompensate(p.ctl)) {
                     try {
                         do {} while (!blocker.isReleasable() &&
                                      !blocker.block());
@@ -3322,6 +3227,7 @@ public class ForkJoinPool extends AbstractExecutorService {
     private static final long STEALCOUNT;
     private static final long PLOCK;
     private static final long INDEXSEED;
+    private static final long QBASE;
     private static final long QLOCK;
 
     static {
@@ -3341,6 +3247,8 @@ public class ForkJoinPool extends AbstractExecutorService {
             PARKBLOCKER = U.objectFieldOffset
                 (tk.getDeclaredField("parkBlocker"));
             Class wk = WorkQueue.class;
+            QBASE = U.objectFieldOffset
+                (wk.getDeclaredField("base"));
             QLOCK = U.objectFieldOffset
                 (wk.getDeclaredField("qlock"));
             Class ak = ForkJoinTask[].class;
@@ -3354,45 +3262,51 @@ public class ForkJoinPool extends AbstractExecutorService {
         }
 
         submitters = new ThreadLocal();
-        ForkJoinWorkerThreadFactory fac = defaultForkJoinWorkerThreadFactory =
+        defaultForkJoinWorkerThreadFactory =
             new DefaultForkJoinWorkerThreadFactory();
         modifyThreadPermission = new RuntimePermission("modifyThread");
 
-        /*
-         * Establish common pool parameters.  For extra caution,
-         * computations to set up common pool state are here; the
-         * constructor just assigns these values to fields.
-         */
+        common = java.security.AccessController.doPrivileged
+            (new java.security.PrivilegedAction() {
+                public ForkJoinPool run() { return makeCommonPool(); }});
+        int par = common.parallelism; // report 1 even if threads disabled
+        commonParallelism = par > 0 ? par : 1;
+    }
 
-        int par = 0;
-        Thread.UncaughtExceptionHandler handler = null;
-        try {  // TBD: limit or report ignored exceptions?
+    /**
+     * Creates and returns the common pool, respecting user settings
+     * specified via system properties.
+     */
+    private static ForkJoinPool makeCommonPool() {
+        int parallelism = -1;
+        ForkJoinWorkerThreadFactory factory
+            = defaultForkJoinWorkerThreadFactory;
+        UncaughtExceptionHandler handler = null;
+        try {  // ignore exceptions in accessing/parsing properties
             String pp = System.getProperty
                 ("java.util.concurrent.ForkJoinPool.common.parallelism");
-            String hp = System.getProperty
-                ("java.util.concurrent.ForkJoinPool.common.exceptionHandler");
             String fp = System.getProperty
                 ("java.util.concurrent.ForkJoinPool.common.threadFactory");
-            if (fp != null)
-                fac = ((ForkJoinWorkerThreadFactory)ClassLoader.
-                       getSystemClassLoader().loadClass(fp).newInstance());
-            if (hp != null)
-                handler = ((Thread.UncaughtExceptionHandler)ClassLoader.
-                           getSystemClassLoader().loadClass(hp).newInstance());
+            String hp = System.getProperty
+                ("java.util.concurrent.ForkJoinPool.common.exceptionHandler");
             if (pp != null)
-                par = Integer.parseInt(pp);
+                parallelism = Integer.parseInt(pp);
+            if (fp != null)
+                factory = ((ForkJoinWorkerThreadFactory)ClassLoader.
+                           getSystemClassLoader().loadClass(fp).newInstance());
+            if (hp != null)
+                handler = ((UncaughtExceptionHandler)ClassLoader.
+                           getSystemClassLoader().loadClass(hp).newInstance());
         } catch (Exception ignore) {
         }
 
-        if (par <= 0)
-            par = Runtime.getRuntime().availableProcessors();
-        if (par > MAX_CAP)
-            par = MAX_CAP;
-        commonParallelism = par;
-        long np = (long)(-par); // precompute initial ctl value
-        long ct = ((np << AC_SHIFT) & AC_MASK) | ((np << TC_SHIFT) & TC_MASK);
-
-        common = new ForkJoinPool(par, ct, fac, handler);
+        if (parallelism < 0 && // default 1 less than #cores
+            (parallelism = Runtime.getRuntime().availableProcessors() - 1) < 0)
+            parallelism = 0;
+        if (parallelism > MAX_CAP)
+            parallelism = MAX_CAP;
+        return new ForkJoinPool(parallelism, factory, handler, LIFO_QUEUE,
+                                "ForkJoinPool.commonPool-worker-");
     }
 
     /**
diff --git a/src/main/java/jsr166e/ForkJoinTask.java b/src/main/java/jsr166e/ForkJoinTask.java
index e50a5ccd2a8..e23dfbe3f79 100644
--- a/src/main/java/jsr166e/ForkJoinTask.java
+++ b/src/main/java/jsr166e/ForkJoinTask.java
@@ -134,10 +134,9 @@ import java.lang.reflect.Constructor;
  * (DAG). Otherwise, executions may encounter a form of deadlock as
  * tasks cyclically wait for each other.  However, this framework
  * supports other methods and techniques (for example the use of
- * {@link java.util.concurrent.Phaser}, {@link #helpQuiesce}, and
- * {@link #complete}) that
+ * {@link Phaser}, {@link #helpQuiesce}, and {@link #complete}) that
  * may be of use in constructing custom subclasses for problems that
- * are not statically structured as DAGs. To support such usages a
+ * are not statically structured as DAGs. To support such usages, a
  * ForkJoinTask may be atomically tagged with a {@code short}
  * value using {@link #setForkJoinTaskTag} or {@link
  * #compareAndSetForkJoinTaskTag} and checked using {@link
@@ -286,25 +285,35 @@ public abstract class ForkJoinTask implements Future, Serializable {
      */
     private int externalAwaitDone() {
         int s;
-        ForkJoinPool.externalHelpJoin(this);
-        boolean interrupted = false;
-        while ((s = status) >= 0) {
-            if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) {
-                synchronized (this) {
-                    if (status >= 0) {
-                        try {
-                            wait();
-                        } catch (InterruptedException ie) {
-                            interrupted = true;
+        ForkJoinPool cp = ForkJoinPool.common;
+        if ((s = status) >= 0) {
+            if (cp != null) {
+                if (this instanceof CountedCompleter)
+                    s = cp.externalHelpComplete((CountedCompleter)this);
+                else if (cp.tryExternalUnpush(this))
+                    s = doExec();
+            }
+            if (s >= 0 && (s = status) >= 0) {
+                boolean interrupted = false;
+                do {
+                    if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) {
+                        synchronized (this) {
+                            if (status >= 0) {
+                                try {
+                                    wait();
+                                } catch (InterruptedException ie) {
+                                    interrupted = true;
+                                }
+                            }
+                            else
+                                notifyAll();
                         }
                     }
-                    else
-                        notifyAll();
-                }
+                } while ((s = status) >= 0);
+                if (interrupted)
+                    Thread.currentThread().interrupt();
             }
         }
-        if (interrupted)
-            Thread.currentThread().interrupt();
         return s;
     }
 
@@ -313,9 +322,15 @@ public abstract class ForkJoinTask implements Future, Serializable {
      */
     private int externalInterruptibleAwaitDone() throws InterruptedException {
         int s;
+        ForkJoinPool cp = ForkJoinPool.common;
         if (Thread.interrupted())
             throw new InterruptedException();
-        ForkJoinPool.externalHelpJoin(this);
+        if ((s = status) >= 0 && cp != null) {
+            if (this instanceof CountedCompleter)
+                cp.externalHelpComplete((CountedCompleter)this);
+            else if (cp.tryExternalUnpush(this))
+                doExec();
+        }
         while ((s = status) >= 0) {
             if (U.compareAndSwapInt(this, STATUS, s, s | SIGNAL)) {
                 synchronized (this) {
@@ -601,14 +616,9 @@ public abstract class ForkJoinTask implements Future, Serializable {
     /**
      * A version of "sneaky throw" to relay exceptions
      */
-    static void rethrow(final Throwable ex) {
-        if (ex != null) {
-            if (ex instanceof Error)
-                throw (Error)ex;
-            if (ex instanceof RuntimeException)
-                throw (RuntimeException)ex;
+    static void rethrow(Throwable ex) {
+        if (ex != null)
             ForkJoinTask.uncheckedThrow(ex);
-        }
     }
 
     /**
@@ -618,8 +628,7 @@ public abstract class ForkJoinTask implements Future, Serializable {
      */
     @SuppressWarnings("unchecked") static 
         void uncheckedThrow(Throwable t) throws T {
-        if (t != null)
-            throw (T)t; // rely on vacuous cast
+        throw (T)t; // rely on vacuous cast
     }
 
     /**
@@ -830,7 +839,7 @@ public abstract class ForkJoinTask implements Future, Serializable {
      * 
This method is designed to be invoked by other
      * tasks. To terminate the current task, you can just return or
      * throw an unchecked exception from its computation method, or
-     * invoke {@link #completeExceptionally}.
+     * invoke {@link #completeExceptionally(Throwable)}.
      *
      * @param mayInterruptIfRunning this value has no effect in the
      * default implementation because interrupts are not used to
@@ -982,6 +991,7 @@ public abstract class ForkJoinTask implements Future, Serializable {
         // Messy in part because we measure in nanosecs, but wait in millisecs
         int s; long ms;
         long ns = unit.toNanos(timeout);
+        ForkJoinPool cp;
         if ((s = status) >= 0 && ns > 0L) {
             long deadline = System.nanoTime() + ns;
             ForkJoinPool p = null;
@@ -993,8 +1003,12 @@ public abstract class ForkJoinTask implements Future, Serializable {
                 w = wt.workQueue;
                 p.helpJoinOnce(w, this); // no retries on failure
             }
-            else
-                ForkJoinPool.externalHelpJoin(this);
+            else if ((cp = ForkJoinPool.common) != null) {
+                if (this instanceof CountedCompleter)
+                    cp.externalHelpComplete((CountedCompleter)this);
+                else if (cp.tryExternalUnpush(this))
+                    doExec();
+            }
             boolean canBlock = false;
             boolean interrupted = false;
             try {
@@ -1002,7 +1016,7 @@ public abstract class ForkJoinTask implements Future, Serializable {
                     if (w != null && w.qlock < 0)
                         cancelIgnoringExceptions(this);
                     else if (!canBlock) {
-                        if (p == null || p.tryCompensate())
+                        if (p == null || p.tryCompensate(p.ctl))
                             canBlock = true;
                     }
                     else {
@@ -1143,7 +1157,7 @@ public abstract class ForkJoinTask implements Future, Serializable {
         Thread t;
         return (((t = Thread.currentThread()) instanceof ForkJoinWorkerThread) ?
                 ((ForkJoinWorkerThread)t).workQueue.tryUnpush(this) :
-                ForkJoinPool.tryExternalUnpush(this));
+                ForkJoinPool.common.tryExternalUnpush(this));
     }
 
     /**
@@ -1312,7 +1326,7 @@ public abstract class ForkJoinTask implements Future, Serializable {
      *
      * @param e the expected tag value
      * @param tag the new tag value
-     * @return true if successful; i.e., the current value was
+     * @return {@code true} if successful; i.e., the current value was
      * equal to e and is now tag.
      * @since 1.8
      */
@@ -1364,6 +1378,24 @@ public abstract class ForkJoinTask implements Future, Serializable {
         private static final long serialVersionUID = 5232453952276885070L;
     }
 
+    /**
+     * Adaptor for Runnables in which failure forces worker exception
+     */
+    static final class RunnableExecuteAction extends ForkJoinTask {
+        final Runnable runnable;
+        RunnableExecuteAction(Runnable runnable) {
+            if (runnable == null) throw new NullPointerException();
+            this.runnable = runnable;
+        }
+        public final Void getRawResult() { return null; }
+        public final void setRawResult(Void v) { }
+        public final boolean exec() { runnable.run(); return true; }
+        void internalPropagateException(Throwable ex) {
+            rethrow(ex); // rethrow outside exec() catches.
+        }
+        private static final long serialVersionUID = 5232453952276885070L;
+    }
+
     /**
      * Adaptor for Callables
      */
diff --git a/src/main/java/jsr166e/ForkJoinWorkerThread.java b/src/main/java/jsr166e/ForkJoinWorkerThread.java
index 7abf42e7fd4..dc32aa6872a 100644
--- a/src/main/java/jsr166e/ForkJoinWorkerThread.java
+++ b/src/main/java/jsr166e/ForkJoinWorkerThread.java
@@ -6,6 +6,7 @@
 
 package jsr166e;
 
+
 /**
  * A thread managed by a {@link ForkJoinPool}, which executes
  * {@link ForkJoinTask}s.
@@ -14,8 +15,8 @@ package jsr166e;
  * scheduling or execution.  However, you can override initialization
  * and termination methods surrounding the main task processing loop.
  * If you do create such a subclass, you will also need to supply a
- * custom {@link ForkJoinPool.ForkJoinWorkerThreadFactory} to use it
- * in a {@code ForkJoinPool}.
+ * custom {@link ForkJoinPool.ForkJoinWorkerThreadFactory} to
+ * {@linkplain ForkJoinPool#ForkJoinPool use it} in a {@code ForkJoinPool}.
  *
  * @since 1.7
  * @author Doug Lea
@@ -60,16 +61,17 @@ public class ForkJoinWorkerThread extends Thread {
     }
 
     /**
-     * Returns the index number of this thread in its pool.  The
-     * returned value ranges from zero to the maximum number of
-     * threads (minus one) that have ever been created in the pool.
-     * This method may be useful for applications that track status or
-     * collect results per-worker rather than per-task.
+     * Returns the unique index number of this thread in its pool.
+     * The returned value ranges from zero to the maximum number of
+     * threads (minus one) that may exist in the pool, and does not
+     * change during the lifetime of the thread.  This method may be
+     * useful for applications that track status or collect results
+     * per-worker-thread rather than per-task.
      *
      * @return the index number
      */
     public int getPoolIndex() {
-        return workQueue.poolIndex;
+        return workQueue.poolIndex >>> 1; // ignore odd/even tag bit
     }
 
     /**
diff --git a/src/main/java/jsr166e/StampedLock.java b/src/main/java/jsr166e/StampedLock.java
index 8196710d951..de8697f6163 100644
--- a/src/main/java/jsr166e/StampedLock.java
+++ b/src/main/java/jsr166e/StampedLock.java
@@ -5,10 +5,8 @@
  */
 
 package jsr166e;
-
-import jsr166y.ThreadLocalRandom;
-
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.ReadWriteLock;
@@ -120,34 +118,17 @@ import java.util.concurrent.locks.LockSupport;
  *     }
  *   }
  *
- *   double distanceFromOriginV1() { // A read-only method
- *     long stamp;
- *     if ((stamp = sl.tryOptimisticRead()) != 0L) { // optimistic
- *       double currentX = x;
- *       double currentY = y;
- *       if (sl.validate(stamp))
- *         return Math.sqrt(currentX * currentX + currentY * currentY);
- *     }
- *     stamp = sl.readLock(); // fall back to read lock
- *     try {
- *       double currentX = x;
- *       double currentY = y;
- *         return Math.sqrt(currentX * currentX + currentY * currentY);
- *     } finally {
- *       sl.unlockRead(stamp);
- *     }
- *   }
- *
- *   double distanceFromOriginV2() { // combines code paths
- *     double currentX = 0.0, currentY = 0.0;
- *     for (long stamp = sl.tryOptimisticRead(); ; stamp = sl.readLock()) {
- *       try {
- *         currentX = x;
- *         currentY = y;
- *       } finally {
- *         if (sl.tryConvertToOptimisticRead(stamp) != 0L) // unlock or validate
- *           break;
- *       }
+ *   double distanceFromOrigin() { // A read-only method
+ *     long stamp = sl.tryOptimisticRead();
+ *     double currentX = x, currentY = y;
+ *     if (!sl.validate(stamp)) {
+ *        stamp = sl.readLock();
+ *        try {
+ *          currentX = x;
+ *          currentY = y;
+ *        } finally {
+ *           sl.unlockRead(stamp);
+ *        }
  *     }
  *     return Math.sqrt(currentX * currentX + currentY * currentY);
  *   }
@@ -359,6 +340,8 @@ public class StampedLock implements java.io.Serializable {
      * Behavior under timeout and interruption matches that specified
      * for method {@link Lock#tryLock(long,TimeUnit)}.
      *
+     * @param time the maximum time to wait for the lock
+     * @param unit the time unit of the {@code time} argument
      * @return a stamp that can be used to unlock or convert mode,
      * or zero if the lock is not available
      * @throws InterruptedException if the current thread is interrupted
@@ -438,6 +421,8 @@ public class StampedLock implements java.io.Serializable {
      * Behavior under timeout and interruption matches that specified
      * for method {@link Lock#tryLock(long,TimeUnit)}.
      *
+     * @param time the maximum time to wait for the lock
+     * @param unit the time unit of the {@code time} argument
      * @return a stamp that can be used to unlock or convert mode,
      * or zero if the lock is not available
      * @throws InterruptedException if the current thread is interrupted
@@ -503,7 +488,8 @@ public class StampedLock implements java.io.Serializable {
      * obtained from {@link #tryOptimisticRead} or a locking method
      * for this lock has no defined effect or result.
      *
-     * @return true if the lock has not been exclusively acquired
+     * @param stamp a stamp
+     * @return {@code true} if the lock has not been exclusively acquired
      * since issuance of the given stamp; else false
      */
     public boolean validate(long stamp) {
@@ -716,7 +702,7 @@ public class StampedLock implements java.io.Serializable {
      * stamp value. This method may be useful for recovery after
      * errors.
      *
-     * @return true if the lock was held, else false
+     * @return {@code true} if the lock was held, else false
      */
     public boolean tryUnlockWrite() {
         long s; WNode h;
@@ -734,7 +720,7 @@ public class StampedLock implements java.io.Serializable {
      * requiring a stamp value. This method may be useful for recovery
      * after errors.
      *
-     * @return true if the read lock was held, else false
+     * @return {@code true} if the read lock was held, else false
      */
     public boolean tryUnlockRead() {
         long s, m; WNode h;
@@ -752,30 +738,66 @@ public class StampedLock implements java.io.Serializable {
         return false;
     }
 
+    // status monitoring methods
+
     /**
-     * Returns true if the lock is currently held exclusively.
+     * Returns combined state-held and overflow read count for given
+     * state s.
+     */
+    private int getReadLockCount(long s) {
+        long readers;
+        if ((readers = s & RBITS) >= RFULL)
+            readers = RFULL + readerOverflow;
+        return (int) readers;
+    }
+
+    /**
+     * Returns {@code true} if the lock is currently held exclusively.
      *
-     * @return true if the lock is currently held exclusively
+     * @return {@code true} if the lock is currently held exclusively
      */
     public boolean isWriteLocked() {
         return (state & WBIT) != 0L;
     }
 
     /**
-     * Returns true if the lock is currently held non-exclusively.
+     * Returns {@code true} if the lock is currently held non-exclusively.
      *
-     * @return true if the lock is currently held non-exclusively
+     * @return {@code true} if the lock is currently held non-exclusively
      */
     public boolean isReadLocked() {
         return (state & RBITS) != 0L;
     }
 
-    private void readObject(java.io.ObjectInputStream s)
-        throws java.io.IOException, ClassNotFoundException {
-        s.defaultReadObject();
-        state = ORIGIN; // reset to unlocked state
+    /**
+     * Queries the number of read locks held for this lock. This
+     * method is designed for use in monitoring system state, not for
+     * synchronization control.
+     * @return the number of read locks held
+     */
+    public int getReadLockCount() {
+        return getReadLockCount(state);
     }
 
+    /**
+     * Returns a string identifying this lock, as well as its lock
+     * state.  The state, in brackets, includes the String {@code
+     * "Unlocked"} or the String {@code "Write-locked"} or the String
+     * {@code "Read-locks:"} followed by the current number of
+     * read-locks held.
+     *
+     * @return a string identifying this lock, as well as its lock state
+     */
+    public String toString() {
+        long s = state;
+        return super.toString() +
+            ((s & ABITS) == 0L ? "[Unlocked]" :
+             (s & WBIT) != 0L ? "[Write-locked]" :
+             "[Read-locks:" + getReadLockCount(s) + "]");
+    }
+
+    // views
+
     /**
      * Returns a plain {@link Lock} view of this StampedLock in which
      * the {@link Lock#lock} method is mapped to {@link #readLock},
@@ -890,6 +912,12 @@ public class StampedLock implements java.io.Serializable {
         }
     }
 
+    private void readObject(java.io.ObjectInputStream s)
+        throws java.io.IOException, ClassNotFoundException {
+        s.defaultReadObject();
+        state = ORIGIN; // reset to unlocked state
+    }
+
     // internals
 
     /**
@@ -901,7 +929,7 @@ public class StampedLock implements java.io.Serializable {
      * @return new stamp on success, else zero
      */
     private long tryIncReaderOverflow(long s) {
-        // assert (s & ABITS) >= RFULL
+        // assert (s & ABITS) >= RFULL;
         if ((s & ABITS) == RFULL) {
             if (U.compareAndSwapLong(this, STATE, s, s | RBITS)) {
                 ++readerOverflow;
@@ -922,7 +950,7 @@ public class StampedLock implements java.io.Serializable {
      * @return new stamp on success, else zero
      */
     private long tryDecReaderOverflow(long s) {
-        // assert (s & ABITS) >= RFULL
+        // assert (s & ABITS) >= RFULL;
         if ((s & ABITS) == RFULL) {
             if (U.compareAndSwapLong(this, STATE, s, s | RBITS)) {
                 int r; long next;
@@ -1044,11 +1072,14 @@ public class StampedLock implements java.io.Serializable {
                     time = 0L;
                 else if ((time = deadline - System.nanoTime()) <= 0L)
                     return cancelWaiter(node, node, false);
-                node.thread = Thread.currentThread();
+                Thread wt = Thread.currentThread();
+                U.putObject(wt, PARKBLOCKER, this); // emulate LockSupport.park
+                node.thread = wt;
                 if (node.prev == p && p.status == WAITING && // recheck
                     (p != whead || (state & ABITS) != 0L))
                     U.park(false, time);
                 node.thread = null;
+                U.putObject(wt, PARKBLOCKER, null);
                 if (interruptible && Thread.interrupted())
                     return cancelWaiter(node, node, true);
             }
@@ -1113,8 +1144,6 @@ public class StampedLock implements java.io.Serializable {
                                            node.cowait = p.cowait, node)) {
                     node.thread = Thread.currentThread();
                     for (long time;;) {
-                        if (interruptible && Thread.interrupted())
-                            return cancelWaiter(node, p, true);
                         if (deadline == 0L)
                             time = 0L;
                         else if ((time = deadline - System.nanoTime()) <= 0L)
@@ -1126,9 +1155,14 @@ public class StampedLock implements java.io.Serializable {
                             node.thread = null;
                             break;
                         }
+                        Thread wt = Thread.currentThread();
+                        U.putObject(wt, PARKBLOCKER, this);
                         if (node.thread == null) // must recheck
                             break;
                         U.park(false, time);
+                        U.putObject(wt, PARKBLOCKER, null);
+                        if (interruptible && Thread.interrupted())
+                            return cancelWaiter(node, p, true);
                     }
                     group = p;
                 }
@@ -1184,11 +1218,14 @@ public class StampedLock implements java.io.Serializable {
                     time = 0L;
                 else if ((time = deadline - System.nanoTime()) <= 0L)
                     return cancelWaiter(node, node, false);
-                node.thread = Thread.currentThread();
+                Thread wt = Thread.currentThread();
+                U.putObject(wt, PARKBLOCKER, this);
+                node.thread = wt;
                 if (node.prev == p && p.status == WAITING &&
                     (p != whead || (state & ABITS) != WBIT))
                     U.park(false, time);
                 node.thread = null;
+                U.putObject(wt, PARKBLOCKER, null);
                 if (interruptible && Thread.interrupted())
                     return cancelWaiter(node, node, true);
             }
@@ -1289,6 +1326,7 @@ public class StampedLock implements java.io.Serializable {
     private static final long WNEXT;
     private static final long WSTATUS;
     private static final long WCOWAIT;
+    private static final long PARKBLOCKER;
 
     static {
         try {
@@ -1307,6 +1345,9 @@ public class StampedLock implements java.io.Serializable {
                 (wk.getDeclaredField("next"));
             WCOWAIT = U.objectFieldOffset
                 (wk.getDeclaredField("cowait"));
+            Class tk = Thread.class;
+            PARKBLOCKER = U.objectFieldOffset
+                (tk.getDeclaredField("parkBlocker"));
 
         } catch (Exception e) {
             throw new Error(e);
diff --git a/src/main/java/jsr166e/extra/AtomicDouble.java b/src/main/java/jsr166e/extra/AtomicDouble.java
index 2ae6cc0c7d6..4a176135671 100644
--- a/src/main/java/jsr166e/extra/AtomicDouble.java
+++ b/src/main/java/jsr166e/extra/AtomicDouble.java
@@ -19,7 +19,7 @@ import static java.lang.Double.longBitsToDouble;
  * this class does extend {@code Number} to allow uniform access by
  * tools and utilities that deal with numerically-based classes.
  *
- * 
This class compares primitive {@code double}
+ * 
This class compares primitive {@code double}
  * values in methods such as {@link #compareAndSet} by comparing their
  * bitwise representation using {@link Double#doubleToRawLongBits},
  * which differs from both the primitive double {@code ==} operator
@@ -29,7 +29,7 @@ import static java.lang.Double.longBitsToDouble;
  *   long xBits = Double.doubleToRawLongBits(x);
  *   long yBits = Double.doubleToRawLongBits(y);
  *   return xBits == yBits;
- * }}

+ * }}
* * @see jsr166e.DoubleAdder * @see jsr166e.DoubleMaxUpdater @@ -123,11 +123,10 @@ public class AtomicDouble extends Number implements java.io.Serializable { * if the current value is bitwise equal * to the expected value. * - *

May - * fail spuriously - * and does not provide ordering guarantees, so is only rarely an - * appropriate alternative to {@code compareAndSet}. + * May fail spuriously and does not provide ordering guarantees, + * so is only rarely an appropriate alternative to {@code compareAndSet}. * * @param expect the expected value * @param update the new value diff --git a/src/main/java/jsr166e/extra/AtomicDoubleArray.java b/src/main/java/jsr166e/extra/AtomicDoubleArray.java index 1f6cfec6785..8d56c51f031 100644 --- a/src/main/java/jsr166e/extra/AtomicDoubleArray.java +++ b/src/main/java/jsr166e/extra/AtomicDoubleArray.java @@ -14,7 +14,7 @@ import static java.lang.Double.longBitsToDouble; * See the {@link java.util.concurrent.atomic} package specification * for description of the properties of atomic variables. * - *

This class compares primitive {@code double} + *

This class compares primitive {@code double} * values in methods such as {@link #compareAndSet} by comparing their * bitwise representation using {@link Double#doubleToRawLongBits}, * which differs from both the primitive double {@code ==} operator @@ -24,7 +24,7 @@ import static java.lang.Double.longBitsToDouble; * long xBits = Double.doubleToRawLongBits(x); * long yBits = Double.doubleToRawLongBits(y); * return xBits == yBits; - * }} + * }} * * @author Doug Lea * @author Martin Buchholz @@ -162,11 +162,10 @@ public class AtomicDoubleArray implements java.io.Serializable { * if the current value is bitwise equal * to the expected value. * - *

May - * fail spuriously - * and does not provide ordering guarantees, so is only rarely an - * appropriate alternative to {@code compareAndSet}. + * May fail spuriously and does not provide ordering guarantees, + * so is only rarely an appropriate alternative to {@code compareAndSet}. * * @param i the index * @param expect the expected value diff --git a/src/main/java/jsr166e/package-info.java b/src/main/java/jsr166e/package-info.java deleted file mode 100644 index 36625802d70..00000000000 --- a/src/main/java/jsr166e/package-info.java +++ /dev/null @@ -1,9 +0,0 @@ -/* - * Written by Doug Lea with assistance from members of JCP JSR-166 - * Expert Group and released to the public domain, as explained at - * http://creativecommons.org/publicdomain/zero/1.0/ - */ - - -// Built on 2013-02-21 -package jsr166e; diff --git a/src/main/java/jsr166y/package-info.java b/src/main/java/jsr166y/package-info.java index 3dad8ecb119..b6e19b97965 100644 --- a/src/main/java/jsr166y/package-info.java +++ b/src/main/java/jsr166y/package-info.java @@ -26,5 +26,5 @@ * are those that directly implement this algorithmic design pattern. */ -// Built on 2013-02-21 +// Built on 2013-07-10 package jsr166y;