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/* |
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* 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 |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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* Other contributors include Andrew Wright, Jeffrey Hayes, |
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* Pat Fisher, Mike Judd. |
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*/ |
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|
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import junit.framework.*; |
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import java.util.*; |
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import java.util.concurrent.*; |
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import static java.util.concurrent.TimeUnit.MILLISECONDS; |
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|
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public class CountDownLatchTest extends JSR166TestCase { |
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public static void main(String[] args) { |
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junit.textui.TestRunner.run(suite()); |
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} |
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public static Test suite() { |
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return new TestSuite(CountDownLatchTest.class); |
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} |
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|
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/** |
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* negative constructor argument throws IAE |
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*/ |
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public void testConstructor() { |
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try { |
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new CountDownLatch(-1); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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/** |
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* getCount returns initial count and decreases after countDown |
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*/ |
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public void testGetCount() { |
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final CountDownLatch l = new CountDownLatch(2); |
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assertEquals(2, l.getCount()); |
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l.countDown(); |
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assertEquals(1, l.getCount()); |
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} |
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|
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/** |
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* countDown decrements count when positive and has no effect when zero |
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*/ |
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public void testCountDown() { |
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final CountDownLatch l = new CountDownLatch(1); |
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assertEquals(1, l.getCount()); |
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l.countDown(); |
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assertEquals(0, l.getCount()); |
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l.countDown(); |
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assertEquals(0, l.getCount()); |
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} |
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|
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/** |
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* await returns after countDown to zero, but not before |
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*/ |
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public void testAwait() throws InterruptedException { |
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final CountDownLatch l = new CountDownLatch(2); |
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|
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Thread t = new Thread(new CheckedRunnable() { |
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public void realRun() throws InterruptedException { |
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assertTrue(l.getCount() > 0); |
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l.await(); |
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assertEquals(0, l.getCount()); |
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}}); |
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|
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t.start(); |
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assertEquals(l.getCount(), 2); |
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delay(SHORT_DELAY_MS); |
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l.countDown(); |
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assertEquals(l.getCount(), 1); |
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l.countDown(); |
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assertEquals(l.getCount(), 0); |
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t.join(); |
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} |
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|
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/** |
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* timed await returns after countDown to zero |
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*/ |
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public void testTimedAwait() throws InterruptedException { |
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final CountDownLatch l = new CountDownLatch(2); |
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|
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Thread t = new Thread(new CheckedRunnable() { |
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public void realRun() throws InterruptedException { |
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assertTrue(l.getCount() > 0); |
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assertTrue(l.await(SMALL_DELAY_MS, MILLISECONDS)); |
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}}); |
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|
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t.start(); |
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assertEquals(l.getCount(), 2); |
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delay(SHORT_DELAY_MS); |
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l.countDown(); |
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assertEquals(l.getCount(), 1); |
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l.countDown(); |
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assertEquals(l.getCount(), 0); |
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t.join(); |
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} |
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|
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/** |
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* await throws IE if interrupted before counted down |
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*/ |
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public void testAwait_InterruptedException() throws InterruptedException { |
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final CountDownLatch l = new CountDownLatch(1); |
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Thread t = new Thread(new CheckedInterruptedRunnable() { |
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public void realRun() throws InterruptedException { |
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assertTrue(l.getCount() > 0); |
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l.await(); |
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}}); |
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|
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t.start(); |
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assertEquals(l.getCount(), 1); |
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t.interrupt(); |
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t.join(); |
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} |
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|
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/** |
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* timed await throws IE if interrupted before counted down |
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*/ |
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public void testTimedAwait_InterruptedException() throws InterruptedException { |
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final CountDownLatch l = new CountDownLatch(1); |
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Thread t = new Thread(new CheckedInterruptedRunnable() { |
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public void realRun() throws InterruptedException { |
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assertTrue(l.getCount() > 0); |
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l.await(MEDIUM_DELAY_MS, MILLISECONDS); |
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}}); |
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|
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t.start(); |
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delay(SHORT_DELAY_MS); |
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assertEquals(l.getCount(), 1); |
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t.interrupt(); |
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t.join(); |
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} |
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|
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/** |
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* timed await times out if not counted down before timeout |
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*/ |
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public void testAwaitTimeout() throws InterruptedException { |
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final CountDownLatch l = new CountDownLatch(1); |
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Thread t = new Thread(new CheckedRunnable() { |
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public void realRun() throws InterruptedException { |
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assertTrue(l.getCount() > 0); |
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assertFalse(l.await(SHORT_DELAY_MS, MILLISECONDS)); |
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assertTrue(l.getCount() > 0); |
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}}); |
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|
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t.start(); |
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assertEquals(l.getCount(), 1); |
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t.join(); |
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} |
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|
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/** |
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* toString indicates current count |
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*/ |
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public void testToString() { |
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CountDownLatch s = new CountDownLatch(2); |
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assertTrue(s.toString().contains("Count = 2")); |
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s.countDown(); |
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assertTrue(s.toString().contains("Count = 1")); |
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s.countDown(); |
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assertTrue(s.toString().contains("Count = 0")); |
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} |
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|
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} |