/*
* 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.AtomicBoolean;
import java.util.concurrent.locks.Lock;
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 SemaphoreReadWriteLockJUnitTest {
private static final long OPERATION_TIMEOUT_MILLIS = 10 * 1000;
private CountDownLatch latch;
private CountDownLatch waitToLock;
@Rule
public Timeout timeout = new Timeout(30, TimeUnit.SECONDS);
@Before
public void setUp() throws Exception {
latch = new CountDownLatch(1);
waitToLock = new CountDownLatch(1);
}
@After
public void tearDown() throws Exception {
waitToLock.countDown();
latch.countDown();
}
@Test
public void testReaderWaitsForWriter() throws Exception {
SemaphoreReadWriteLock rwl = new SemaphoreReadWriteLock();
final Lock rl = rwl.readLock();
final Lock wl = rwl.writeLock();
wl.lock();
Thread writer = new Thread(new Runnable() {
@Override
public void run() {
waitToLock.countDown();
rl.lock();
latch.countDown();
rl.unlock();
}
});
writer.start();
assertTrue(waitToLock.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertEquals(1, latch.getCount());
wl.unlock();
assertTrue(latch.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
}
@Test
public void testWriterWaitsForReader() throws Exception {
SemaphoreReadWriteLock rwl = new SemaphoreReadWriteLock();
final Lock rl = rwl.readLock();
final Lock wl = rwl.writeLock();
rl.lock();
Thread writer = new Thread(new Runnable() {
@Override
public void run() {
waitToLock.countDown();
wl.lock();
latch.countDown();
wl.unlock();
}
});
writer.start();
assertTrue(waitToLock.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertEquals(1, latch.getCount());
rl.unlock();
assertTrue(latch.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
}
@Test
public void testReadersNotBlockedByReaders() throws Exception {
SemaphoreReadWriteLock rwl = new SemaphoreReadWriteLock();
final Lock rl = rwl.readLock();
final Lock wl = rwl.writeLock();
rl.lock();
Thread reader = new Thread(new Runnable() {
@Override
public void run() {
waitToLock.countDown();
rl.lock();
latch.countDown();
}
});
reader.start();
assertTrue(waitToLock.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertTrue(latch.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
}
@Test
public void testWritersBlockedByWriters() throws Exception {
SemaphoreReadWriteLock rwl = new SemaphoreReadWriteLock();
final Lock rl = rwl.readLock();
final Lock wl = rwl.writeLock();
wl.lock();
Thread writer = new Thread(new Runnable() {
@Override
public void run() {
waitToLock.countDown();
wl.lock();
latch.countDown();
wl.unlock();
}
});
writer.start();
assertTrue(waitToLock.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertEquals(1, latch.getCount());
wl.unlock();
assertTrue(latch.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
}
@Test
public void testTryLock() throws Exception {
SemaphoreReadWriteLock rwl = new SemaphoreReadWriteLock();
final Lock rl = rwl.readLock();
final Lock wl = rwl.writeLock();
assertTrue(wl.tryLock());
final AtomicBoolean failed = new AtomicBoolean(false);
Thread reader = new Thread(new Runnable() {
@Override
public void run() {
waitToLock.countDown();
if (rl.tryLock()) {
failed.set(true);
}
latch.countDown();
}
});
reader.start();
assertTrue(waitToLock.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertTrue(latch.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
assertFalse(failed.get());
}
@Test
public void testLockAndReleaseByDifferentThreads() throws Exception {
SemaphoreReadWriteLock rwl = new SemaphoreReadWriteLock();
final Lock rl = rwl.readLock();
final Lock wl = rwl.writeLock();
rl.lock();
Thread writer = new Thread(new Runnable() {
@Override
public void run() {
waitToLock.countDown();
try {
assertTrue(wl.tryLock(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
} catch (InterruptedException e) {
throw new AssertionError(e);
}
latch.countDown();
}
});
writer.start();
Thread reader2 = new Thread(new Runnable() {
@Override
public void run() {
try {
assertTrue(waitToLock.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
} catch (InterruptedException e) {
throw new AssertionError(e);
}
rl.unlock();
}
});
reader2.start();
assertTrue(latch.await(OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS));
}
}