/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional information regarding
* copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License. You may obtain a
* copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package org.apache.geode.internal.util.concurrent;
import static org.junit.Assert.*;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.rules.Timeout;
import org.apache.geode.test.junit.categories.UnitTest;
@Category(UnitTest.class)
public class ReentrantSemaphoreJUnitTest {
private static final long OPERATION_TIMEOUT_MILLIS = 10 * 1000;
private CountDownLatch done;
private CountDownLatch acquired;
@Rule
public Timeout timeout = new Timeout(30, TimeUnit.SECONDS);
@Before
public void setUp() throws Exception {
done = new CountDownLatch(1);
acquired = new CountDownLatch(2);
}
@After
public void tearDown() throws Exception {
acquired.countDown();
done.countDown();
}
@Test
public void testOneThread() throws Exception {
final ReentrantSemaphore semaphore = new ReentrantSemaphore(2);
semaphore.acquire();
semaphore.acquire();
assertEquals(1, semaphore.availablePermits());
semaphore.release();
semaphore.release();
assertEquals(2, semaphore.availablePermits());
}
@Test
public void testMultipleThreads() throws Exception {
final ReentrantSemaphore sem = new ReentrantSemaphore(2);
final AtomicReference<Throwable> failure = new AtomicReference<>();
Thread t1 = new Thread() {
public void run() {
try {
sem.acquire();
sem.acquire();
sem.acquire();
acquired.countDown();
assertTrue(done.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
sem.release();
sem.release();
sem.release();
} catch (Exception e) {
failure.compareAndSet(null, e);
}
}
};
t1.start();
Thread t2 = new Thread() {
public void run() {
try {
sem.acquire();
sem.acquire();
sem.acquire();
acquired.countDown();
assertTrue(done.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
sem.release();
sem.release();
sem.release();
} catch (Exception e) {
failure.compareAndSet(null, e);
}
}
};
t2.start();
Thread t3 = new Thread() {
public void run() {
try {
assertTrue(acquired.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertEquals(0, sem.availablePermits());
assertFalse(sem.tryAcquire(1, TimeUnit.SECONDS));
} catch (Exception e) {
failure.compareAndSet(null, e);
}
}
};
t3.start();
t3.join(OPERATION_TIMEOUT_MILLIS);
assertFalse(t3.isAlive());
done.countDown();
t2.join(OPERATION_TIMEOUT_MILLIS);
assertFalse(t3.isAlive());
t1.join(OPERATION_TIMEOUT_MILLIS);
assertFalse(t1.isAlive());
if (failure.get() != null) {
throw new AssertionError(failure.get());
}
assertEquals(2, sem.availablePermits());
}
}