1 |
/* |
2 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
4 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
* Other contributors include Andrew Wright, Jeffrey Hayes, |
6 |
* Pat Fisher, Mike Judd. |
7 |
*/ |
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|
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import static java.util.concurrent.TimeUnit.MILLISECONDS; |
10 |
|
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import java.util.ArrayList; |
12 |
import java.util.Arrays; |
13 |
import java.util.Collection; |
14 |
import java.util.Iterator; |
15 |
import java.util.NoSuchElementException; |
16 |
import java.util.concurrent.BlockingQueue; |
17 |
import java.util.concurrent.CountDownLatch; |
18 |
import java.util.concurrent.Executors; |
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import java.util.concurrent.ExecutorService; |
20 |
import java.util.concurrent.SynchronousQueue; |
21 |
|
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import junit.framework.Test; |
23 |
|
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public class SynchronousQueueTest extends JSR166TestCase { |
25 |
|
26 |
public static class Fair extends BlockingQueueTest { |
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protected BlockingQueue emptyCollection() { |
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return new SynchronousQueue(true); |
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} |
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} |
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|
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public static class NonFair extends BlockingQueueTest { |
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protected BlockingQueue emptyCollection() { |
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return new SynchronousQueue(false); |
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} |
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} |
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|
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public static void main(String[] args) { |
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main(suite(), args); |
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} |
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|
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public static Test suite() { |
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return newTestSuite(SynchronousQueueTest.class, |
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new Fair().testSuite(), |
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new NonFair().testSuite()); |
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} |
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|
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/** |
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* Any SynchronousQueue is both empty and full |
50 |
*/ |
51 |
public void testEmptyFull() { testEmptyFull(false); } |
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public void testEmptyFull_fair() { testEmptyFull(true); } |
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public void testEmptyFull(boolean fair) { |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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assertTrue(q.isEmpty()); |
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mustEqual(0, q.size()); |
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mustEqual(0, q.remainingCapacity()); |
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assertFalse(q.offer(zero)); |
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} |
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|
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/** |
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* offer fails if no active taker |
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*/ |
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public void testOffer() { testOffer(false); } |
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public void testOffer_fair() { testOffer(true); } |
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public void testOffer(boolean fair) { |
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SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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assertFalse(q.offer(one)); |
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} |
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|
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/** |
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* add throws IllegalStateException if no active taker |
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*/ |
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public void testAdd() { testAdd(false); } |
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public void testAdd_fair() { testAdd(true); } |
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public void testAdd(boolean fair) { |
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SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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mustEqual(0, q.remainingCapacity()); |
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try { |
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q.add(one); |
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shouldThrow(); |
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} catch (IllegalStateException success) {} |
83 |
} |
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|
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/** |
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* addAll(this) throws IllegalArgumentException |
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*/ |
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public void testAddAll_self() { testAddAll_self(false); } |
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public void testAddAll_self_fair() { testAddAll_self(true); } |
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public void testAddAll_self(boolean fair) { |
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SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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try { |
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q.addAll(q); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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/**S |
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* addAll throws IllegalStateException if no active taker |
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*/ |
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public void testAddAll_ISE() { testAddAll_ISE(false); } |
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public void testAddAll_ISE_fair() { testAddAll_ISE(true); } |
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public void testAddAll_ISE(boolean fair) { |
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SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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Item[] items = seqItems(1); |
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Collection<Item> coll = Arrays.asList(items); |
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try { |
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q.addAll(coll); |
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shouldThrow(); |
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} catch (IllegalStateException success) {} |
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} |
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|
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/** |
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* put blocks interruptibly if no active taker |
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*/ |
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public void testBlockingPut() { testBlockingPut(false); } |
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public void testBlockingPut_fair() { testBlockingPut(true); } |
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public void testBlockingPut(boolean fair) { |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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final CountDownLatch pleaseInterrupt = new CountDownLatch(1); |
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Thread t = newStartedThread(new CheckedRunnable() { |
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public void realRun() throws InterruptedException { |
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Thread.currentThread().interrupt(); |
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try { |
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q.put(ninetynine); |
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shouldThrow(); |
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} catch (InterruptedException success) {} |
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assertFalse(Thread.interrupted()); |
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|
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pleaseInterrupt.countDown(); |
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try { |
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q.put(ninetynine); |
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shouldThrow(); |
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} catch (InterruptedException success) {} |
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assertFalse(Thread.interrupted()); |
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}}); |
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|
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await(pleaseInterrupt); |
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if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING); |
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t.interrupt(); |
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awaitTermination(t); |
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mustEqual(0, q.remainingCapacity()); |
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} |
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|
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/** |
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* put blocks interruptibly waiting for take |
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*/ |
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public void testPutWithTake() { testPutWithTake(false); } |
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public void testPutWithTake_fair() { testPutWithTake(true); } |
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public void testPutWithTake(boolean fair) { |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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final CountDownLatch pleaseTake = new CountDownLatch(1); |
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final CountDownLatch pleaseInterrupt = new CountDownLatch(1); |
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Thread t = newStartedThread(new CheckedRunnable() { |
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public void realRun() throws InterruptedException { |
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pleaseTake.countDown(); |
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q.put(one); |
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|
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Thread.currentThread().interrupt(); |
160 |
try { |
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q.put(ninetynine); |
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shouldThrow(); |
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} catch (InterruptedException success) {} |
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assertFalse(Thread.interrupted()); |
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|
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pleaseInterrupt.countDown(); |
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try { |
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q.put(ninetynine); |
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shouldThrow(); |
170 |
} catch (InterruptedException success) {} |
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assertFalse(Thread.interrupted()); |
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}}); |
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|
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await(pleaseTake); |
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mustEqual(0, q.remainingCapacity()); |
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try { assertSame(one, q.take()); } |
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catch (InterruptedException e) { threadUnexpectedException(e); } |
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|
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await(pleaseInterrupt); |
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if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING); |
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t.interrupt(); |
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awaitTermination(t); |
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mustEqual(0, q.remainingCapacity()); |
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} |
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|
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/** |
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* timed offer times out if elements not taken |
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*/ |
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public void testTimedOffer() { |
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final boolean fair = randomBoolean(); |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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final CountDownLatch pleaseInterrupt = new CountDownLatch(1); |
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Thread t = newStartedThread(new CheckedRunnable() { |
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public void realRun() throws InterruptedException { |
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long startTime = System.nanoTime(); |
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|
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assertFalse(q.offer(zero, timeoutMillis(), MILLISECONDS)); |
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assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
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|
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Thread.currentThread().interrupt(); |
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try { |
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q.offer(one, randomTimeout(), randomTimeUnit()); |
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shouldThrow(); |
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} catch (InterruptedException success) {} |
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assertFalse(Thread.interrupted()); |
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|
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pleaseInterrupt.countDown(); |
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try { |
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q.offer(two, LONGER_DELAY_MS, MILLISECONDS); |
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shouldThrow(); |
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} catch (InterruptedException success) {} |
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assertFalse(Thread.interrupted()); |
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}}); |
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|
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await(pleaseInterrupt); |
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if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING); |
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t.interrupt(); |
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awaitTermination(t); |
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} |
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|
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/** |
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* poll return null if no active putter |
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*/ |
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public void testPoll() { testPoll(false); } |
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public void testPoll_fair() { testPoll(true); } |
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public void testPoll(boolean fair) { |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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assertNull(q.poll()); |
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} |
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|
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/** |
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* timed poll with zero timeout times out if no active putter |
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*/ |
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public void testTimedPoll0() { testTimedPoll0(false); } |
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public void testTimedPoll0_fair() { testTimedPoll0(true); } |
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public void testTimedPoll0(boolean fair) { |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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try { assertNull(q.poll(0, MILLISECONDS)); } |
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catch (InterruptedException e) { threadUnexpectedException(e); } |
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} |
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|
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/** |
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* timed poll with nonzero timeout times out if no active putter |
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*/ |
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public void testTimedPoll() { |
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final boolean fair = randomBoolean(); |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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final long startTime = System.nanoTime(); |
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try { assertNull(q.poll(timeoutMillis(), MILLISECONDS)); } |
250 |
catch (InterruptedException e) { threadUnexpectedException(e); } |
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assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
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} |
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|
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/** |
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* timed poll before a delayed offer times out, returning null; |
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* after offer succeeds; on interruption throws |
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*/ |
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public void testTimedPollWithOffer() { |
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final boolean fair = randomBoolean(); |
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final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
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final CountDownLatch pleaseOffer = new CountDownLatch(1); |
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final CountDownLatch pleaseInterrupt = new CountDownLatch(1); |
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Thread t = newStartedThread(new CheckedRunnable() { |
264 |
public void realRun() throws InterruptedException { |
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long startTime = System.nanoTime(); |
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assertNull(q.poll(timeoutMillis(), MILLISECONDS)); |
267 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
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|
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pleaseOffer.countDown(); |
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startTime = System.nanoTime(); |
271 |
assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS)); |
272 |
|
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Thread.currentThread().interrupt(); |
274 |
try { |
275 |
q.poll(randomTimeout(), randomTimeUnit()); |
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shouldThrow(); |
277 |
} catch (InterruptedException success) {} |
278 |
assertFalse(Thread.interrupted()); |
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|
280 |
pleaseInterrupt.countDown(); |
281 |
try { |
282 |
q.poll(LONG_DELAY_MS, MILLISECONDS); |
283 |
shouldThrow(); |
284 |
} catch (InterruptedException success) {} |
285 |
assertFalse(Thread.interrupted()); |
286 |
|
287 |
assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS); |
288 |
}}); |
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|
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await(pleaseOffer); |
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long startTime = System.nanoTime(); |
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try { assertTrue(q.offer(zero, LONG_DELAY_MS, MILLISECONDS)); } |
293 |
catch (InterruptedException e) { threadUnexpectedException(e); } |
294 |
assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS); |
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|
296 |
await(pleaseInterrupt); |
297 |
if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING); |
298 |
t.interrupt(); |
299 |
awaitTermination(t); |
300 |
} |
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|
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/** |
303 |
* peek() returns null if no active putter |
304 |
*/ |
305 |
public void testPeek() { testPeek(false); } |
306 |
public void testPeek_fair() { testPeek(true); } |
307 |
public void testPeek(boolean fair) { |
308 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
309 |
assertNull(q.peek()); |
310 |
} |
311 |
|
312 |
/** |
313 |
* element() throws NoSuchElementException if no active putter |
314 |
*/ |
315 |
public void testElement() { testElement(false); } |
316 |
public void testElement_fair() { testElement(true); } |
317 |
public void testElement(boolean fair) { |
318 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
319 |
try { |
320 |
q.element(); |
321 |
shouldThrow(); |
322 |
} catch (NoSuchElementException success) {} |
323 |
} |
324 |
|
325 |
/** |
326 |
* remove() throws NoSuchElementException if no active putter |
327 |
*/ |
328 |
public void testRemove() { testRemove(false); } |
329 |
public void testRemove_fair() { testRemove(true); } |
330 |
public void testRemove(boolean fair) { |
331 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
332 |
try { |
333 |
q.remove(); |
334 |
shouldThrow(); |
335 |
} catch (NoSuchElementException success) {} |
336 |
} |
337 |
|
338 |
/** |
339 |
* contains returns false |
340 |
*/ |
341 |
public void testContains() { testContains(false); } |
342 |
public void testContains_fair() { testContains(true); } |
343 |
public void testContains(boolean fair) { |
344 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
345 |
assertFalse(q.contains(zero)); |
346 |
} |
347 |
|
348 |
/** |
349 |
* clear ensures isEmpty |
350 |
*/ |
351 |
public void testClear() { testClear(false); } |
352 |
public void testClear_fair() { testClear(true); } |
353 |
public void testClear(boolean fair) { |
354 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
355 |
q.clear(); |
356 |
assertTrue(q.isEmpty()); |
357 |
} |
358 |
|
359 |
/** |
360 |
* containsAll returns false unless empty |
361 |
*/ |
362 |
public void testContainsAll() { testContainsAll(false); } |
363 |
public void testContainsAll_fair() { testContainsAll(true); } |
364 |
public void testContainsAll(boolean fair) { |
365 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
366 |
Item[] empty = new Item[0]; |
367 |
assertTrue(q.containsAll(Arrays.asList(empty))); |
368 |
Item[] items = new Item[1]; items[0] = zero; |
369 |
assertFalse(q.containsAll(Arrays.asList(items))); |
370 |
} |
371 |
|
372 |
/** |
373 |
* retainAll returns false |
374 |
*/ |
375 |
public void testRetainAll() { testRetainAll(false); } |
376 |
public void testRetainAll_fair() { testRetainAll(true); } |
377 |
public void testRetainAll(boolean fair) { |
378 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
379 |
Item[] empty = new Item[0]; |
380 |
assertFalse(q.retainAll(Arrays.asList(empty))); |
381 |
Item[] items = new Item[1]; items[0] = zero; |
382 |
assertFalse(q.retainAll(Arrays.asList(items))); |
383 |
} |
384 |
|
385 |
/** |
386 |
* removeAll returns false |
387 |
*/ |
388 |
public void testRemoveAll() { testRemoveAll(false); } |
389 |
public void testRemoveAll_fair() { testRemoveAll(true); } |
390 |
public void testRemoveAll(boolean fair) { |
391 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
392 |
Item[] empty = new Item[0]; |
393 |
assertFalse(q.removeAll(Arrays.asList(empty))); |
394 |
Item[] items = new Item[1]; items[0] = zero; |
395 |
assertFalse(q.containsAll(Arrays.asList(items))); |
396 |
} |
397 |
|
398 |
/** |
399 |
* toArray is empty |
400 |
*/ |
401 |
public void testToArray() { testToArray(false); } |
402 |
public void testToArray_fair() { testToArray(true); } |
403 |
public void testToArray(boolean fair) { |
404 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
405 |
Object[] o = q.toArray(); |
406 |
mustEqual(0, o.length); |
407 |
} |
408 |
|
409 |
/** |
410 |
* toArray(Item array) returns its argument with the first |
411 |
* element (if present) nulled out |
412 |
*/ |
413 |
public void testToArray2() { testToArray2(false); } |
414 |
public void testToArray2_fair() { testToArray2(true); } |
415 |
public void testToArray2(boolean fair) { |
416 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
417 |
Item[] a; |
418 |
|
419 |
a = new Item[0]; |
420 |
assertSame(a, q.toArray(a)); |
421 |
|
422 |
a = new Item[3]; |
423 |
Arrays.fill(a, fortytwo); |
424 |
assertSame(a, q.toArray(a)); |
425 |
assertNull(a[0]); |
426 |
for (int i = 1; i < a.length; i++) |
427 |
mustEqual(42, a[i]); |
428 |
} |
429 |
|
430 |
/** |
431 |
* toArray(null) throws NPE |
432 |
*/ |
433 |
public void testToArray_null() { testToArray_null(false); } |
434 |
public void testToArray_null_fair() { testToArray_null(true); } |
435 |
public void testToArray_null(boolean fair) { |
436 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
437 |
try { |
438 |
Object[] unused = q.toArray((Object[])null); |
439 |
shouldThrow(); |
440 |
} catch (NullPointerException success) {} |
441 |
} |
442 |
|
443 |
/** |
444 |
* iterator does not traverse any elements |
445 |
*/ |
446 |
public void testIterator() { testIterator(false); } |
447 |
public void testIterator_fair() { testIterator(true); } |
448 |
public void testIterator(boolean fair) { |
449 |
assertIteratorExhausted(new SynchronousQueue<Item>(fair).iterator()); |
450 |
} |
451 |
|
452 |
/** |
453 |
* iterator remove throws IllegalStateException |
454 |
*/ |
455 |
public void testIteratorRemove() { testIteratorRemove(false); } |
456 |
public void testIteratorRemove_fair() { testIteratorRemove(true); } |
457 |
public void testIteratorRemove(boolean fair) { |
458 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
459 |
Iterator<? extends Item> it = q.iterator(); |
460 |
try { |
461 |
it.remove(); |
462 |
shouldThrow(); |
463 |
} catch (IllegalStateException success) {} |
464 |
} |
465 |
|
466 |
/** |
467 |
* toString returns a non-null string |
468 |
*/ |
469 |
public void testToString() { testToString(false); } |
470 |
public void testToString_fair() { testToString(true); } |
471 |
public void testToString(boolean fair) { |
472 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
473 |
String s = q.toString(); |
474 |
assertNotNull(s); |
475 |
} |
476 |
|
477 |
/** |
478 |
* offer transfers elements across Executor tasks |
479 |
*/ |
480 |
public void testOfferInExecutor() { testOfferInExecutor(false); } |
481 |
public void testOfferInExecutor_fair() { testOfferInExecutor(true); } |
482 |
public void testOfferInExecutor(boolean fair) { |
483 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
484 |
final CheckedBarrier threadsStarted = new CheckedBarrier(2); |
485 |
final ExecutorService executor = Executors.newFixedThreadPool(2); |
486 |
try (PoolCleaner cleaner = cleaner(executor)) { |
487 |
|
488 |
executor.execute(new CheckedRunnable() { |
489 |
public void realRun() throws InterruptedException { |
490 |
assertFalse(q.offer(one)); |
491 |
threadsStarted.await(); |
492 |
assertTrue(q.offer(one, LONG_DELAY_MS, MILLISECONDS)); |
493 |
mustEqual(0, q.remainingCapacity()); |
494 |
}}); |
495 |
|
496 |
executor.execute(new CheckedRunnable() { |
497 |
public void realRun() throws InterruptedException { |
498 |
threadsStarted.await(); |
499 |
assertSame(one, q.take()); |
500 |
}}); |
501 |
} |
502 |
} |
503 |
|
504 |
/** |
505 |
* timed poll retrieves elements across Executor threads |
506 |
*/ |
507 |
public void testPollInExecutor() { testPollInExecutor(false); } |
508 |
public void testPollInExecutor_fair() { testPollInExecutor(true); } |
509 |
public void testPollInExecutor(boolean fair) { |
510 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
511 |
final CheckedBarrier threadsStarted = new CheckedBarrier(2); |
512 |
final ExecutorService executor = Executors.newFixedThreadPool(2); |
513 |
try (PoolCleaner cleaner = cleaner(executor)) { |
514 |
executor.execute(new CheckedRunnable() { |
515 |
public void realRun() throws InterruptedException { |
516 |
assertNull(q.poll()); |
517 |
threadsStarted.await(); |
518 |
assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS)); |
519 |
assertTrue(q.isEmpty()); |
520 |
}}); |
521 |
|
522 |
executor.execute(new CheckedRunnable() { |
523 |
public void realRun() throws InterruptedException { |
524 |
threadsStarted.await(); |
525 |
q.put(one); |
526 |
}}); |
527 |
} |
528 |
} |
529 |
|
530 |
/** |
531 |
* a deserialized/reserialized queue is usable |
532 |
*/ |
533 |
public void testSerialization() { |
534 |
final SynchronousQueue<Item> x = new SynchronousQueue<>(); |
535 |
final SynchronousQueue<Item> y = new SynchronousQueue<>(false); |
536 |
final SynchronousQueue<Item> z = new SynchronousQueue<>(true); |
537 |
assertSerialEquals(x, y); |
538 |
assertNotSerialEquals(x, z); |
539 |
SynchronousQueue[] rqs = { x, y, z }; |
540 |
@SuppressWarnings("unchecked") |
541 |
SynchronousQueue<Item>[] qs = (SynchronousQueue<Item>[])rqs; |
542 |
for (SynchronousQueue<Item> q : qs) { |
543 |
SynchronousQueue<Item> clone = serialClone(q); |
544 |
assertNotSame(q, clone); |
545 |
assertSerialEquals(q, clone); |
546 |
assertTrue(clone.isEmpty()); |
547 |
mustEqual(0, clone.size()); |
548 |
mustEqual(0, clone.remainingCapacity()); |
549 |
assertFalse(clone.offer(zero)); |
550 |
} |
551 |
} |
552 |
|
553 |
/** |
554 |
* drainTo(c) of empty queue doesn't transfer elements |
555 |
*/ |
556 |
public void testDrainTo() { testDrainTo(false); } |
557 |
public void testDrainTo_fair() { testDrainTo(true); } |
558 |
public void testDrainTo(boolean fair) { |
559 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
560 |
ArrayList<Item> l = new ArrayList<>(); |
561 |
q.drainTo(l); |
562 |
mustEqual(0, q.size()); |
563 |
mustEqual(0, l.size()); |
564 |
} |
565 |
|
566 |
/** |
567 |
* drainTo empties queue, unblocking a waiting put. |
568 |
*/ |
569 |
public void testDrainToWithActivePut() { testDrainToWithActivePut(false); } |
570 |
public void testDrainToWithActivePut_fair() { testDrainToWithActivePut(true); } |
571 |
public void testDrainToWithActivePut(boolean fair) { |
572 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(fair); |
573 |
Thread t = newStartedThread(new CheckedRunnable() { |
574 |
public void realRun() throws InterruptedException { |
575 |
q.put(one); |
576 |
}}); |
577 |
|
578 |
ArrayList<Item> l = new ArrayList<>(); |
579 |
long startTime = System.nanoTime(); |
580 |
while (l.isEmpty()) { |
581 |
q.drainTo(l); |
582 |
if (millisElapsedSince(startTime) > LONG_DELAY_MS) |
583 |
fail("timed out"); |
584 |
Thread.yield(); |
585 |
} |
586 |
mustEqual(1, l.size()); |
587 |
assertSame(one, l.get(0)); |
588 |
awaitTermination(t); |
589 |
} |
590 |
|
591 |
/** |
592 |
* drainTo(c, n) empties up to n elements of queue into c |
593 |
*/ |
594 |
public void testDrainToN() throws InterruptedException { |
595 |
final SynchronousQueue<Item> q = new SynchronousQueue<>(); |
596 |
Thread t1 = newStartedThread(new CheckedRunnable() { |
597 |
public void realRun() throws InterruptedException { |
598 |
q.put(one); |
599 |
}}); |
600 |
|
601 |
Thread t2 = newStartedThread(new CheckedRunnable() { |
602 |
public void realRun() throws InterruptedException { |
603 |
q.put(two); |
604 |
}}); |
605 |
|
606 |
ArrayList<Item> l = new ArrayList<>(); |
607 |
int drained; |
608 |
while ((drained = q.drainTo(l, 1)) == 0) Thread.yield(); |
609 |
mustEqual(1, drained); |
610 |
mustEqual(1, l.size()); |
611 |
while ((drained = q.drainTo(l, 1)) == 0) Thread.yield(); |
612 |
mustEqual(1, drained); |
613 |
mustEqual(2, l.size()); |
614 |
assertTrue(l.contains(one)); |
615 |
assertTrue(l.contains(two)); |
616 |
awaitTermination(t1); |
617 |
awaitTermination(t2); |
618 |
} |
619 |
|
620 |
/** |
621 |
* remove(null), contains(null) always return false |
622 |
*/ |
623 |
public void testNeverContainsNull() { |
624 |
Collection<?> q = new SynchronousQueue<>(); |
625 |
assertFalse(q.contains(null)); |
626 |
assertFalse(q.remove(null)); |
627 |
} |
628 |
|
629 |
} |