/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* 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/
* Other contributors include Andrew Wright, Jeffrey Hayes,
* Pat Fisher, Mike Judd.
*/
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import java.util.concurrent.CountDownLatch;
import junit.framework.Test;
import junit.framework.TestSuite;
public class CountDownLatchTest extends JSR166TestCase {
public static void main(String[] args) {
main(suite(), args);
}
public static Test suite() {
return new TestSuite(CountDownLatchTest.class);
}
/**
* negative constructor argument throws IAE
*/
public void testConstructor() {
try {
new CountDownLatch(-1);
shouldThrow();
} catch (IllegalArgumentException success) {}
}
/**
* getCount returns initial count and decreases after countDown
*/
public void testGetCount() {
final CountDownLatch l = new CountDownLatch(2);
assertEquals(2, l.getCount());
l.countDown();
assertEquals(1, l.getCount());
}
/**
* countDown decrements count when positive and has no effect when zero
*/
public void testCountDown() {
final CountDownLatch l = new CountDownLatch(1);
assertEquals(1, l.getCount());
l.countDown();
assertEquals(0, l.getCount());
l.countDown();
assertEquals(0, l.getCount());
}
/**
* await returns after countDown to zero, but not before
*/
public void testAwait() {
final CountDownLatch l = new CountDownLatch(2);
final CountDownLatch pleaseCountDown = new CountDownLatch(1);
Thread t = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
assertEquals(2, l.getCount());
pleaseCountDown.countDown();
l.await();
assertEquals(0, l.getCount());
}});
await(pleaseCountDown);
assertEquals(2, l.getCount());
l.countDown();
assertEquals(1, l.getCount());
assertThreadStaysAlive(t);
l.countDown();
assertEquals(0, l.getCount());
awaitTermination(t);
}
/**
* timed await returns after countDown to zero
*/
public void testTimedAwait() {
final CountDownLatch l = new CountDownLatch(2);
final CountDownLatch pleaseCountDown = new CountDownLatch(1);
Thread t = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
assertEquals(2, l.getCount());
pleaseCountDown.countDown();
assertTrue(l.await(LONG_DELAY_MS, MILLISECONDS));
assertEquals(0, l.getCount());
}});
await(pleaseCountDown);
assertEquals(2, l.getCount());
l.countDown();
assertEquals(1, l.getCount());
assertThreadStaysAlive(t);
l.countDown();
assertEquals(0, l.getCount());
awaitTermination(t);
}
/**
* await throws IE if interrupted before counted down
*/
public void testAwait_Interruptible() {
final CountDownLatch l = new CountDownLatch(1);
final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
Thread t = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
Thread.currentThread().interrupt();
try {
l.await();
shouldThrow();
} catch (InterruptedException success) {}
assertFalse(Thread.interrupted());
pleaseInterrupt.countDown();
try {
l.await();
shouldThrow();
} catch (InterruptedException success) {}
assertFalse(Thread.interrupted());
assertEquals(1, l.getCount());
}});
await(pleaseInterrupt);
assertThreadStaysAlive(t);
t.interrupt();
awaitTermination(t);
}
/**
* timed await throws IE if interrupted before counted down
*/
public void testTimedAwait_Interruptible() {
final CountDownLatch l = new CountDownLatch(1);
final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
Thread t = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
Thread.currentThread().interrupt();
try {
l.await(LONG_DELAY_MS, MILLISECONDS);
shouldThrow();
} catch (InterruptedException success) {}
assertFalse(Thread.interrupted());
pleaseInterrupt.countDown();
try {
l.await(LONG_DELAY_MS, MILLISECONDS);
shouldThrow();
} catch (InterruptedException success) {}
assertFalse(Thread.interrupted());
assertEquals(1, l.getCount());
}});
await(pleaseInterrupt);
assertThreadStaysAlive(t);
t.interrupt();
awaitTermination(t);
}
/**
* timed await times out if not counted down before timeout
*/
public void testAwaitTimeout() throws InterruptedException {
final CountDownLatch l = new CountDownLatch(1);
Thread t = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
assertEquals(1, l.getCount());
assertFalse(l.await(timeoutMillis(), MILLISECONDS));
assertEquals(1, l.getCount());
}});
awaitTermination(t);
assertEquals(1, l.getCount());
}
/**
* toString indicates current count
*/
public void testToString() {
CountDownLatch s = new CountDownLatch(2);
assertTrue(s.toString().contains("Count = 2"));
s.countDown();
assertTrue(s.toString().contains("Count = 1"));
s.countDown();
assertTrue(s.toString().contains("Count = 0"));
}
}