ARTEMIS-2569 LinkedListImpl tests should not rely on the GC mechanism

This commit is contained in:
Francesco Nigro 2019-12-06 11:09:35 +01:00 committed by Clebert Suconic
parent 2733cd73bd
commit 6cc5749c7b
2 changed files with 127 additions and 116 deletions

View File

@ -161,9 +161,13 @@ public class LinkedListImpl<E> implements LinkedList<E> {
@Override
public void clear() {
tail = head.next = null;
// Clearing all of the links between nodes is "unnecessary", but:
// - helps a generational GC if the discarded nodes inhabit
// more than one generation
// - is sure to free memory even if there is a reachable Iterator
while (poll() != null) {
size = 0;
}
}
@Override
@ -308,6 +312,14 @@ public class LinkedListImpl<E> implements LinkedList<E> {
return (T) this;
}
protected final LinkedListImpl.Node<T> next() {
return next;
}
protected final LinkedListImpl.Node<T> prev() {
return prev;
}
@Override
public String toString() {
return val() == this ? "Intrusive Node" : "Node, value = " + val();

View File

@ -16,13 +16,10 @@
*/
package org.apache.activemq.artemis.tests.unit.util;
import java.lang.ref.WeakReference;
import java.util.Comparator;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.activemq.artemis.tests.util.ActiveMQTestBase;
import org.apache.activemq.artemis.tests.util.RandomUtil;
@ -40,7 +37,6 @@ public class LinkedListTest extends ActiveMQTestBase {
@Before
public void setUp() throws Exception {
super.setUp();
list = new LinkedListImpl<>(integerComparator);
}
@ -111,151 +107,111 @@ public class LinkedListTest extends ActiveMQTestBase {
integerIterator.close();
}
@Test
public void testAddAndRemove() {
final AtomicInteger count = new AtomicInteger(0);
class MyObject {
private static final class ObservableNode extends LinkedListImpl.Node<ObservableNode> {
private final byte[] payload;
ObservableNode() {
MyObject() {
count.incrementAndGet();
payload = new byte[10 * 1024];
}
@Override
protected void finalize() throws Exception {
count.decrementAndGet();
}
}
LinkedListImpl<MyObject> objs = new LinkedListImpl<>();
public LinkedListImpl.Node<ObservableNode> publicNext() {
return next();
}
public LinkedListImpl.Node<ObservableNode> publicPrev() {
return prev();
}
}
@Test
public void testAddAndRemove() {
LinkedListImpl<ObservableNode> objs = new LinkedListImpl<>();
// Initial add
for (int i = 0; i < 100; i++) {
objs.addTail(new MyObject());
final ObservableNode o = new ObservableNode();
objs.addTail(o);
}
LinkedListIterator<MyObject> iter = objs.iterator();
try (LinkedListIterator<ObservableNode> iter = objs.iterator()) {
for (int i = 0; i < 500; i++) {
for (int i = 0; i < 500; i++) {
for (int add = 0; add < 1000; add++) {
objs.addTail(new MyObject());
for (int add = 0; add < 1000; add++) {
final ObservableNode o = new ObservableNode();
objs.addTail(o);
assertNotNull("prev", o.publicPrev());
assertNull("next", o.publicNext());
}
for (int remove = 0; remove < 1000; remove++) {
final ObservableNode next = iter.next();
assertNotNull(next);
assertNotNull("prev", next.publicPrev());
//it's ok to check this, because we've *at least* 100 elements left!
assertNotNull("next", next.publicNext());
iter.remove();
assertNull("prev", next.publicPrev());
assertNull("next", next.publicNext());
}
assertEquals(100, objs.size());
}
for (int remove = 0; remove < 1000; remove++) {
assertNotNull(iter.next());
while (iter.hasNext()) {
final ObservableNode next = iter.next();
assertNotNull(next);
iter.remove();
}
if (i % 100 == 0) {
assertCount(100, count);
assertNull("prev", next.publicPrev());
assertNull("next", next.publicNext());
}
}
assertCount(100, count);
while (iter.hasNext()) {
iter.next();
iter.remove();
}
assertCount(0, count);
assertEquals(0, objs.size());
}
@Test
public void testAddHeadAndRemove() {
final AtomicInteger count = new AtomicInteger(0);
class MyObject {
public int payload;
MyObject(int payloadcount) {
count.incrementAndGet();
this.payload = payloadcount;
}
@Override
protected void finalize() throws Exception {
count.decrementAndGet();
}
@Override
public String toString() {
return "" + payload;
}
}
LinkedListImpl<MyObject> objs = new LinkedListImpl<>();
LinkedListImpl<ObservableNode> objs = new LinkedListImpl<>();
// Initial add
for (int i = 1000; i >= 0; i--) {
objs.addHead(new MyObject(i));
for (int i = 0; i < 1001; i++) {
final ObservableNode o = new ObservableNode();
objs.addHead(o);
}
assertCount(1001, count);
LinkedListIterator<MyObject> iter = objs.iterator();
assertEquals(1001, objs.size());
int countLoop = 0;
for (countLoop = 0; countLoop <= 1000; countLoop++) {
MyObject obj = iter.next();
assertEquals(countLoop, obj.payload);
if (countLoop == 500 || countLoop == 1000) {
iter.remove();
try (LinkedListIterator<ObservableNode> iter = objs.iterator()) {
int removed = 0;
for (countLoop = 0; countLoop <= 1000; countLoop++) {
final ObservableNode obj = iter.next();
Assert.assertNotNull(obj);
if (countLoop == 500 || countLoop == 1000) {
assertNotNull("prev", obj.publicPrev());
iter.remove();
assertNull("prev", obj.publicPrev());
assertNull("next", obj.publicNext());
removed++;
}
}
assertEquals(1001 - removed, objs.size());
}
iter.close();
iter = objs.iterator();
countLoop = 0;
while (iter.hasNext()) {
if (countLoop == 500 || countLoop == 1000) {
System.out.println("Jumping " + countLoop);
final int expectedSize = objs.size();
try (LinkedListIterator<ObservableNode> iter = objs.iterator()) {
countLoop = 0;
while (iter.hasNext()) {
final ObservableNode obj = iter.next();
assertNotNull(obj);
countLoop++;
}
MyObject obj = iter.next();
assertEquals(countLoop, obj.payload);
countLoop++;
Assert.assertEquals(expectedSize, countLoop);
}
assertCount(999, count);
// it's needed to add this line here because IBM JDK calls finalize on all objects in list
// before previous assert is called and fails the test, this will prevent it
objs.clear();
}
/**
* @param count
*/
private void assertCount(final int expected, final AtomicInteger count) {
long timeout = System.currentTimeMillis() + 15000;
int seqCount = 0;
while (timeout > System.currentTimeMillis() && count.get() != expected) {
seqCount++;
if (seqCount > 5) {
LinkedList<String> toOME = new LinkedList<>();
int someCount = 0;
try {
WeakReference<Object> ref = new WeakReference<>(new Object());
while (ref.get() != null) {
toOME.add("sdlfkjshadlfkjhas dlfkjhas dlfkjhads lkjfhads lfkjhads flkjashdf " + someCount++);
}
} catch (Throwable expectedThrowable) {
}
toOME.clear();
}
forceGC();
}
assertEquals(expected, count.get());
}
@Test
@ -850,6 +806,49 @@ public class LinkedListTest extends ActiveMQTestBase {
}
@Test
public void testGCNepotismPoll() {
final int count = 100;
final LinkedListImpl<ObservableNode> list = new LinkedListImpl<>();
for (int i = 0; i < count; i++) {
final ObservableNode node = new ObservableNode();
assertNull(node.publicPrev());
assertNull(node.publicNext());
list.addTail(node);
assertNotNull(node.publicPrev());
}
ObservableNode node;
int removed = 0;
while ((node = list.poll()) != null) {
assertNull(node.publicPrev());
assertNull(node.publicNext());
removed++;
}
assertEquals(count, removed);
assertEquals(0, list.size());
}
@Test
public void testGCNepotismClear() {
final int count = 100;
final ObservableNode[] nodes = new ObservableNode[count];
final LinkedListImpl<ObservableNode> list = new LinkedListImpl<>();
for (int i = 0; i < count; i++) {
final ObservableNode node = new ObservableNode();
assertNull(node.publicPrev());
assertNull(node.publicNext());
nodes[i] = node;
list.addTail(node);
assertNotNull(node.publicPrev());
}
list.clear();
for (ObservableNode node : nodes) {
assertNull(node.publicPrev());
assertNull(node.publicNext());
}
assertEquals(0, list.size());
}
@Test
public void testClear() {