From 81adb704c8e578db82e15245ea48a3efe732965d Mon Sep 17 00:00:00 2001
From: Mike Drob <mdrob@apache.org>
Date: Wed, 10 Oct 2018 17:49:54 -0500
Subject: [PATCH] HBASE-21287 Allow configuring test master initialization wait
 time.

---
 .../hadoop/hbase/util/JVMClusterUtil.java     | 69 +++++++++++--------
 1 file changed, 39 insertions(+), 30 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/JVMClusterUtil.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/JVMClusterUtil.java
index ee7ecf3fad6..8c92f6660c0 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/JVMClusterUtil.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/JVMClusterUtil.java
@@ -23,12 +23,13 @@ import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Supplier;
 
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.CoordinatedStateManager;
 import org.apache.hadoop.hbase.master.HMaster;
 import org.apache.hadoop.hbase.regionserver.HRegionServer;
 
@@ -162,6 +163,8 @@ public class JVMClusterUtil {
    */
   public static String startup(final List<JVMClusterUtil.MasterThread> masters,
       final List<JVMClusterUtil.RegionServerThread> regionservers) throws IOException {
+    // Implementation note: This method relies on timed sleeps in a loop. It's not great, and
+    // should probably be re-written to use actual synchronization objects, but it's ok for now
 
     Configuration configuration = null;
 
@@ -177,21 +180,9 @@ public class JVMClusterUtil {
     // Wait for an active master
     //  having an active master before starting the region threads allows
     //  then to succeed on their connection to master
-    long startTime = System.currentTimeMillis();
-    while (findActiveMaster(masters) == null) {
-      try {
-        Thread.sleep(100);
-      } catch (InterruptedException e) {
-        throw (InterruptedIOException)new InterruptedIOException().initCause(e);
-      }
-      int startTimeout = configuration != null ? Integer.parseInt(
+    final int startTimeout = configuration != null ? Integer.parseInt(
         configuration.get("hbase.master.start.timeout.localHBaseCluster", "30000")) : 30000;
-      if (System.currentTimeMillis() > startTime + startTimeout) {
-        String msg = "Master not active after " + startTimeout + "ms";
-        Threads.printThreadInfo(System.out, "Thread dump because: " + msg);
-        throw new RuntimeException(msg);
-      }
-    }
+    waitForEvent(startTimeout, "active", () -> findActiveMaster(masters) != null);
 
     if (regionservers != null) {
       for (JVMClusterUtil.RegionServerThread t: regionservers) {
@@ -201,32 +192,50 @@ public class JVMClusterUtil {
 
     // Wait for an active master to be initialized (implies being master)
     //  with this, when we return the cluster is complete
-    startTime = System.currentTimeMillis();
-    final int maxwait = 200000;
+    final int initTimeout = configuration != null ? Integer.parseInt(
+        configuration.get("hbase.master.init.timeout.localHBaseCluster", "200000")) : 200000;
+    waitForEvent(initTimeout, "initialized", () -> {
+        JVMClusterUtil.MasterThread t = findActiveMaster(masters);
+        // master thread should never be null at this point, but let's keep the check anyway
+        return t != null && t.master.isInitialized();
+      }
+    );
+
+    return findActiveMaster(masters).master.getServerName().toString();
+  }
+
+  /**
+   * Utility method to wait some time for an event to occur, and then return control to the caller.
+   * @param millis How long to wait, in milliseconds.
+   * @param action The action that we are waiting for. Will be used in log message if the event
+   *               does not occur.
+   * @param check A Supplier that will be checked periodically to produce an updated true/false
+   *              result indicating if the expected event has happened or not.
+   * @throws InterruptedIOException If we are interrupted while waiting for the event.
+   * @throws RuntimeException If we reach the specified timeout while waiting for the event.
+   */
+  private static void waitForEvent(long millis, String action, Supplier<Boolean> check)
+      throws InterruptedIOException {
+    long end = System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(millis);
+
     while (true) {
-      JVMClusterUtil.MasterThread t = findActiveMaster(masters);
-      if (t != null && t.master.isInitialized()) {
-        return t.master.getServerName().toString();
+      if (check.get()) {
+        return;
       }
-      // REMOVE
-      if (System.currentTimeMillis() > startTime + 10000) {
-        try {
-          Thread.sleep(1000);
-        } catch (InterruptedException e) {
-          throw (InterruptedIOException)new InterruptedIOException().initCause(e);
-        }
-      }
-      if (System.currentTimeMillis() > startTime + maxwait) {
-        String msg = "Master not initialized after " + maxwait + "ms seconds";
+
+      if (System.nanoTime() > end) {
+        String msg = "Master not " + action + " after " + millis + "ms";
         Threads.printThreadInfo(System.out, "Thread dump because: " + msg);
         throw new RuntimeException(msg);
       }
+
       try {
         Thread.sleep(100);
       } catch (InterruptedException e) {
         throw (InterruptedIOException)new InterruptedIOException().initCause(e);
       }
     }
+
   }
 
   /**