/*
* Copyright (C) 2014 The Guava Authors
*
* Licensed 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 com.google.common.util.concurrent;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import com.google.common.collect.ConcurrentHashMultiset;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableMultiset;
import com.google.common.collect.Multiset;
import com.google.common.testing.TestLogHandler;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.Logger;
import junit.framework.TestCase;
/**
* Tests for {@link ListenerCallQueue}.
*/
public class ListenerCallQueueTest extends TestCase {
private static final ListenerCallQueue.Event<Object> THROWING_EVENT =
new ListenerCallQueue.Event<Object>() {
@Override
public void call(Object object) {
throw new RuntimeException();
}
@Override
public String toString() {
return "throwing()";
}
};
public void testEnqueueAndDispatch() {
Object listener = new Object();
ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
queue.addListener(listener, directExecutor());
Multiset<Object> counters = ConcurrentHashMultiset.create();
queue.enqueue(incrementingEvent(counters, listener, 1));
queue.enqueue(incrementingEvent(counters, listener, 2));
queue.enqueue(incrementingEvent(counters, listener, 3));
queue.enqueue(incrementingEvent(counters, listener, 4));
assertEquals(0, counters.size());
queue.dispatch();
assertEquals(multiset(listener, 4), counters);
}
public void testEnqueueAndDispatch_multipleListeners() {
Object listener1 = new Object();
ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
queue.addListener(listener1, directExecutor());
Multiset<Object> counters = ConcurrentHashMultiset.create();
queue.enqueue(incrementingEvent(counters, listener1, 1));
queue.enqueue(incrementingEvent(counters, listener1, 2));
Object listener2 = new Object();
queue.addListener(listener2, directExecutor());
queue.enqueue(incrementingEvent(counters, multiset(listener1, 3, listener2, 1)));
queue.enqueue(incrementingEvent(counters, multiset(listener1, 4, listener2, 2)));
assertEquals(0, counters.size());
queue.dispatch();
assertEquals(multiset(listener1, 4, listener2, 2), counters);
}
public void testEnqueueAndDispatch_withExceptions() {
Object listener = new Object();
ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
queue.addListener(listener, directExecutor());
Multiset<Object> counters = ConcurrentHashMultiset.create();
queue.enqueue(incrementingEvent(counters, listener, 1));
queue.enqueue(THROWING_EVENT);
queue.enqueue(incrementingEvent(counters, listener, 2));
queue.enqueue(THROWING_EVENT);
queue.enqueue(incrementingEvent(counters, listener, 3));
queue.enqueue(THROWING_EVENT);
queue.enqueue(incrementingEvent(counters, listener, 4));
queue.enqueue(THROWING_EVENT);
assertEquals(0, counters.size());
queue.dispatch();
assertEquals(multiset(listener, 4), counters);
}
static final class MyListener {
@Override
public String toString() {
return "MyListener";
}
}
public void testEnqueueAndDispatch_withLabeledExceptions() {
Object listener = new MyListener();
ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
queue.addListener(listener, directExecutor());
queue.enqueue(THROWING_EVENT, "custom-label");
Logger logger = Logger.getLogger(ListenerCallQueue.class.getName());
logger.setLevel(Level.SEVERE);
TestLogHandler logHandler = new TestLogHandler();
logger.addHandler(logHandler);
try {
queue.dispatch();
} finally {
logger.removeHandler(logHandler);
}
assertEquals(1, logHandler.getStoredLogRecords().size());
assertEquals(
"Exception while executing callback: MyListener custom-label",
logHandler.getStoredLogRecords().get(0).getMessage());
}
public void testEnqueueAndDispatch_multithreaded() throws InterruptedException {
Object listener = new Object();
ExecutorService service = Executors.newFixedThreadPool(4);
ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
try {
queue.addListener(listener, service);
final CountDownLatch latch = new CountDownLatch(1);
Multiset<Object> counters = ConcurrentHashMultiset.create();
queue.enqueue(incrementingEvent(counters, listener, 1));
queue.enqueue(incrementingEvent(counters, listener, 2));
queue.enqueue(incrementingEvent(counters, listener, 3));
queue.enqueue(incrementingEvent(counters, listener, 4));
queue.enqueue(countDownEvent(latch));
assertEquals(0, counters.size());
queue.dispatch();
latch.await();
assertEquals(multiset(listener, 4), counters);
} finally {
service.shutdown();
}
}
public void testEnqueueAndDispatch_multithreaded_withThrowingRunnable()
throws InterruptedException {
Object listener = new Object();
ExecutorService service = Executors.newFixedThreadPool(4);
ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
try {
queue.addListener(listener, service);
final CountDownLatch latch = new CountDownLatch(1);
Multiset<Object> counters = ConcurrentHashMultiset.create();
queue.enqueue(incrementingEvent(counters, listener, 1));
queue.enqueue(THROWING_EVENT);
queue.enqueue(incrementingEvent(counters, listener, 2));
queue.enqueue(THROWING_EVENT);
queue.enqueue(incrementingEvent(counters, listener, 3));
queue.enqueue(THROWING_EVENT);
queue.enqueue(incrementingEvent(counters, listener, 4));
queue.enqueue(THROWING_EVENT);
queue.enqueue(countDownEvent(latch));
assertEquals(0, counters.size());
queue.dispatch();
latch.await();
assertEquals(multiset(listener, 4), counters);
} finally {
service.shutdown();
}
}
private ListenerCallQueue.Event<Object> incrementingEvent(
Multiset<Object> counters, Object expectedListener, int expectedCount) {
return incrementingEvent(counters, multiset(expectedListener, expectedCount));
}
private static <T> ImmutableMultiset<T> multiset(T value, int count) {
return multiset(ImmutableMap.of(value, count));
}
private static <T> ImmutableMultiset<T> multiset(T value1, int count1, T value2, int count2) {
return multiset(ImmutableMap.of(value1, count1, value2, count2));
}
private static <T> ImmutableMultiset<T> multiset(Map<T, Integer> counts) {
ImmutableMultiset.Builder<T> builder = ImmutableMultiset.builder();
for (Map.Entry<T, Integer> entry : counts.entrySet()) {
builder.addCopies(entry.getKey(), entry.getValue());
}
return builder.build();
}
private ListenerCallQueue.Event<Object> incrementingEvent(
final Multiset<Object> counters, final Multiset<Object> expected) {
return new ListenerCallQueue.Event<Object>() {
@Override
public void call(Object listener) {
counters.add(listener);
assertEquals(expected.count(listener), counters.count(listener));
}
@Override
public String toString() {
return "incrementing";
}
};
}
private ListenerCallQueue.Event<Object> countDownEvent(final CountDownLatch latch) {
return new ListenerCallQueue.Event<Object>() {
@Override
public void call(Object listener) {
latch.countDown();
}
@Override
public String toString() {
return "countDown";
}
};
}
}