/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* 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.hazelcast.spi.impl.executionservice.impl;
import com.hazelcast.test.HazelcastParallelClassRunner;
import com.hazelcast.test.HazelcastTestSupport;
import com.hazelcast.test.annotation.QuickTest;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
@RunWith(HazelcastParallelClassRunner.class)
@Category(QuickTest.class)
public class DelegateAndSkipOnConcurrentExecutionDecoratorTest
extends HazelcastTestSupport {
@Test
public void givenTheTaskIsNotRunning_whenThreadAttemptToExecuteIt_theTaskWillBeExecuted() throws InterruptedException {
ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newCachedThreadPool();
ResumableCountingRunnable task = new ResumableCountingRunnable();
decorateAndInvokeRunOnDifferentThread(task, executor);
task.awaitExecutionStarted();
task.resumeExecution();
assertEquals(1, task.getExecutionCount());
}
@Test
public void givenTheTaskIsAlreadyRunning_whenThreadAttemptToExecuteIt_theExutionWillBeSkipped() throws InterruptedException {
final ResumableCountingRunnable task = new ResumableCountingRunnable();
final AtomicInteger counter = new AtomicInteger();
SynchronousQueue<Runnable> queue = new SynchronousQueue<Runnable>() {
@Override
public boolean offer(Runnable runnable) {
counter.incrementAndGet();
return super.offer(runnable);
}
};
ThreadPoolExecutor executor = new ThreadPoolExecutor(0, Integer.MAX_VALUE,
60L, TimeUnit.SECONDS, queue);
//start first task
DelegateAndSkipOnConcurrentExecutionDecorator decoratedTask =
decorateAndInvokeRunOnDifferentThread(task, executor);
//wait until the task is running
task.awaitExecutionStarted();
//attempt to start execution from the test thread. this execution should be skipped -> it won't block
decoratedTask.run();
//resume the original task
task.resumeExecution();
assertEquals(1, task.getExecutionCount());
assertEquals(1, counter.get());
}
@Test
public void toString_contains_runnables_info() throws Exception {
ResumableCountingRunnable runnable = new ResumableCountingRunnable();
Executor executor = new Executor() {
@Override
public void execute(Runnable command) {
}
};
String stringified = new DelegateAndSkipOnConcurrentExecutionDecorator(runnable, executor).toString();
assertTrue(stringified.contains("ResumableCountingRunnable"));
}
private DelegateAndSkipOnConcurrentExecutionDecorator decorateAndInvokeRunOnDifferentThread(Runnable task,
Executor executor) {
DelegateAndSkipOnConcurrentExecutionDecorator decoratedTask =
new DelegateAndSkipOnConcurrentExecutionDecorator(task, executor);
new Thread(decoratedTask).run();
return decoratedTask;
}
private class ResumableCountingRunnable implements Runnable {
private final AtomicInteger executionCount = new AtomicInteger();
private final Semaphore resumeSemaphore = new Semaphore(0);
private final Semaphore startedSemaphore = new Semaphore(0);
@Override
public void run() {
executionCount.incrementAndGet();
startedSemaphore.release();
try {
resumeSemaphore.acquire();
} catch (InterruptedException e) {
fail("Thread interrupted while waiting on latch");
}
}
public void awaitExecutionStarted() throws InterruptedException {
startedSemaphore.acquire();
}
public void resumeExecution() {
resumeSemaphore.release();
}
public int getExecutionCount() {
return executionCount.get();
}
@Override
public String toString() {
return "ResumableCountingRunnable{}";
}
}
}