/**
* 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.metrics2.impl;
import java.util.ConcurrentModificationException;
import java.util.concurrent.CountDownLatch;
import org.junit.Test;
import static org.junit.Assert.*;
import static org.mockito.Mockito.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import static org.apache.hadoop.metrics2.impl.SinkQueue.*;
/**
* Test the half-blocking metrics sink queue
*/
public class TestSinkQueue {
private static final Log LOG = LogFactory.getLog(TestSinkQueue.class);
/**
* Test common use case
* @throws Exception
*/
@Test public void testCommon() throws Exception {
final SinkQueue<Integer> q = new SinkQueue<Integer>(2);
q.enqueue(1);
assertEquals("queue front", 1, (int) q.front());
assertEquals("queue back", 1, (int) q.back());
assertEquals("element", 1, (int) q.dequeue());
assertTrue("should enqueue", q.enqueue(2));
q.consume(new Consumer<Integer>() {
@Override public void consume(Integer e) {
assertEquals("element", 2, (int) e);
}
});
assertTrue("should enqueue", q.enqueue(3));
assertEquals("element", 3, (int) q.dequeue());
assertEquals("queue size", 0, q.size());
assertEquals("queue front", null, q.front());
assertEquals("queue back", null, q.back());
}
/**
* Test blocking when queue is empty
* @throws Exception
*/
@Test public void testEmptyBlocking() throws Exception {
testEmptyBlocking(0);
testEmptyBlocking(100);
}
private void testEmptyBlocking(int awhile) throws Exception {
final SinkQueue<Integer> q = new SinkQueue<Integer>(2);
final Runnable trigger = mock(Runnable.class);
// try consuming emtpy equeue and blocking
Thread t = new Thread() {
@Override public void run() {
try {
assertEquals("element", 1, (int) q.dequeue());
q.consume(new Consumer<Integer>() {
@Override public void consume(Integer e) {
assertEquals("element", 2, (int) e);
trigger.run();
}
});
}
catch (InterruptedException e) {
LOG.warn("Interrupted", e);
}
}
};
t.start();
// Should work with or without sleep
if (awhile > 0) {
Thread.sleep(awhile);
}
q.enqueue(1);
q.enqueue(2);
t.join();
verify(trigger).run();
}
/**
* Test nonblocking enqueue when queue is full
* @throws Exception
*/
@Test public void testFull() throws Exception {
final SinkQueue<Integer> q = new SinkQueue<Integer>(1);
q.enqueue(1);
assertTrue("should drop", !q.enqueue(2));
assertEquals("element", 1, (int) q.dequeue());
q.enqueue(3);
q.consume(new Consumer<Integer>() {
@Override public void consume(Integer e) {
assertEquals("element", 3, (int) e);
}
});
assertEquals("queue size", 0, q.size());
}
/**
* Test the consumeAll method
* @throws Exception
*/
@Test public void testConsumeAll() throws Exception {
final int capacity = 64; // arbitrary
final SinkQueue<Integer> q = new SinkQueue<Integer>(capacity);
for (int i = 0; i < capacity; ++i) {
assertTrue("should enqueue", q.enqueue(i));
}
assertTrue("should not enqueue", !q.enqueue(capacity));
final Runnable trigger = mock(Runnable.class);
q.consumeAll(new Consumer<Integer>() {
private int expected = 0;
@Override public void consume(Integer e) {
assertEquals("element", expected++, (int) e);
trigger.run();
}
});
verify(trigger, times(capacity)).run();
}
/**
* Test the consumer throwing exceptions
* @throws Exception
*/
@Test public void testConsumerException() throws Exception {
final SinkQueue<Integer> q = new SinkQueue<Integer>(1);
final RuntimeException ex = new RuntimeException("expected");
q.enqueue(1);
try {
q.consume(new Consumer<Integer>() {
@Override public void consume(Integer e) {
throw ex;
}
});
}
catch (Exception expected) {
assertSame("consumer exception", ex, expected);
}
// The queue should be in consistent state after exception
assertEquals("queue size", 1, q.size());
assertEquals("element", 1, (int) q.dequeue());
}
/**
* Test the clear method
*/
@Test public void testClear() {
final SinkQueue<Integer> q = new SinkQueue<Integer>(128);
for (int i = 0; i < q.capacity() + 97; ++i) {
q.enqueue(i);
}
assertEquals("queue size", q.capacity(), q.size());
q.clear();
assertEquals("queue size", 0, q.size());
}
/**
* Test consumers that take their time.
* @throws Exception
*/
@Test public void testHangingConsumer() throws Exception {
SinkQueue<Integer> q = newSleepingConsumerQueue(2, 1, 2);
assertEquals("queue back", 2, (int) q.back());
assertTrue("should drop", !q.enqueue(3)); // should not block
assertEquals("queue size", 2, q.size());
assertEquals("queue head", 1, (int) q.front());
assertEquals("queue back", 2, (int) q.back());
}
/**
* Test concurrent consumer access, which is illegal
* @throws Exception
*/
@Test public void testConcurrentConsumers() throws Exception {
final SinkQueue<Integer> q = newSleepingConsumerQueue(2, 1);
assertTrue("should enqueue", q.enqueue(2));
assertEquals("queue back", 2, (int) q.back());
assertTrue("should drop", !q.enqueue(3)); // should not block
shouldThrowCME(new Fun() {
@Override public void run() {
q.clear();
}
});
shouldThrowCME(new Fun() {
@Override public void run() throws Exception {
q.consume(null);
}
});
shouldThrowCME(new Fun() {
@Override public void run() throws Exception {
q.consumeAll(null);
}
});
shouldThrowCME(new Fun() {
@Override public void run() throws Exception {
q.dequeue();
}
});
// The queue should still be in consistent state after all the exceptions
assertEquals("queue size", 2, q.size());
assertEquals("queue front", 1, (int) q.front());
assertEquals("queue back", 2, (int) q.back());
}
private void shouldThrowCME(Fun callback) throws Exception {
try {
callback.run();
}
catch (ConcurrentModificationException e) {
LOG.info(e);
return;
}
LOG.error("should've thrown CME");
fail("should've thrown CME");
}
private SinkQueue<Integer> newSleepingConsumerQueue(int capacity,
int... values) throws Exception {
final SinkQueue<Integer> q = new SinkQueue<Integer>(capacity);
for (int i : values) {
q.enqueue(i);
}
final CountDownLatch barrier = new CountDownLatch(1);
Thread t = new Thread() {
@Override public void run() {
try {
Thread.sleep(10); // causes failure without barrier
q.consume(new Consumer<Integer>() {
@Override
public void consume(Integer e) throws InterruptedException {
LOG.info("sleeping");
barrier.countDown();
Thread.sleep(1000 * 86400); // a long time
}
});
}
catch (InterruptedException ex) {
LOG.warn("Interrupted", ex);
}
}
};
t.setName("Sleeping consumer");
t.setDaemon(true); // so jvm can exit
t.start();
barrier.await();
LOG.debug("Returning new sleeping consumer queue");
return q;
}
static interface Fun {
void run() throws Exception;
}
}