/*
* 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.hadoop.hbase.util;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.hadoop.hbase.testclassification.MiscTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.categories.Category;
@Category({MiscTests.class, SmallTests.class})
public class TestWeakObjectPool {
ObjectPool<String, Object> pool;
@Before
public void setUp() {
pool = new WeakObjectPool<>(
new ObjectPool.ObjectFactory<String, Object>() {
@Override
public Object createObject(String key) {
return new Object();
}
});
}
@Test
public void testKeys() {
Object obj1 = pool.get("a");
Object obj2 = pool.get(new String("a"));
Assert.assertSame(obj1, obj2);
Object obj3 = pool.get("b");
Assert.assertNotSame(obj1, obj3);
}
@Test
public void testWeakReference() throws Exception {
Object obj1 = pool.get("a");
int hash1 = System.identityHashCode(obj1);
System.gc();
System.gc();
System.gc();
Thread.sleep(10);
// Sleep a while because references newly becoming stale
// may still remain when calling the {@code purge} method.
pool.purge();
Assert.assertEquals(1, pool.size());
Object obj2 = pool.get("a");
Assert.assertSame(obj1, obj2);
obj1 = null;
obj2 = null;
System.gc();
System.gc();
System.gc();
Thread.sleep(10);
pool.purge();
Assert.assertEquals(0, pool.size());
Object obj3 = pool.get("a");
Assert.assertNotEquals(hash1, System.identityHashCode(obj3));
}
@Test(timeout=1000)
public void testCongestion() throws Exception {
final int THREAD_COUNT = 100;
final AtomicBoolean assertionFailed = new AtomicBoolean();
final AtomicReference<Object> expectedObjRef = new AtomicReference<>();
final CountDownLatch prepareLatch = new CountDownLatch(THREAD_COUNT);
final CountDownLatch startLatch = new CountDownLatch(1);
final CountDownLatch endLatch = new CountDownLatch(THREAD_COUNT);
for (int i=0; i<THREAD_COUNT; i++) {
new Thread() {
@Override
public void run() {
prepareLatch.countDown();
try {
startLatch.await();
Object obj = pool.get("a");
if (! expectedObjRef.compareAndSet(null, obj)) {
if (expectedObjRef.get() != obj) {
assertionFailed.set(true);
}
}
} catch (Exception e) {
assertionFailed.set(true);
} finally {
endLatch.countDown();
}
}
}.start();
}
prepareLatch.await();
startLatch.countDown();
endLatch.await();
if (assertionFailed.get()) {
Assert.fail();
}
}
}