/*
* 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.facebook.presto.concurrent;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Ordering;
import org.testng.annotations.Test;
import java.util.ArrayList;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Future;
import java.util.concurrent.LinkedBlockingDeque;
import static io.airlift.concurrent.Threads.daemonThreadsNamed;
import static org.testng.Assert.assertTrue;
public class TestFairBatchExecutor
{
@Test
public void testSanity()
throws Exception
{
FairBatchExecutor executor = new FairBatchExecutor(1, daemonThreadsNamed("test-%s"));
// first, block the executor until we're ready
final CountDownLatch readyToStart = new CountDownLatch(1);
executor.processBatch(ImmutableList.of(new Callable<Object>()
{
@Override
public Object call()
throws Exception
{
readyToStart.await();
return null;
}
}));
BlockingQueue<Integer> executions = new LinkedBlockingDeque<>();
List<Future<?>> futures = new ArrayList<>();
// the "meetingPoint" is so that we can schedule additional task at a predictable point in the execution
MeetingPoint meetingPoint = new MeetingPoint();
futures.addAll(executor.processBatch(ImmutableList.of(
newTask(1, executions),
newTask(2, executions),
newTask(3, executions),
newTask(4, executions),
newTask(5, meetingPoint, executions),
newTask(6, executions),
newTask(7, executions),
newTask(8, executions),
newTask(9, executions))));
futures.addAll(executor.processBatch(ImmutableList.of(
newTask(2, executions),
newTask(3, executions),
newTask(4, executions),
newTask(5, meetingPoint, executions),
newTask(6, executions))));
futures.addAll(executor.processBatch(ImmutableList.of(
newTask(3, executions),
newTask(4, executions),
newTask(5, meetingPoint, executions),
newTask(6, executions),
newTask(7, executions),
newTask(8, executions))));
readyToStart.countDown();
meetingPoint.waitForArrival();
futures.addAll(executor.processBatch(ImmutableList.of(
newTask(5, executions),
newTask(6, executions),
newTask(7, executions),
newTask(8, executions),
newTask(9, executions))));
meetingPoint.notifyAdvance();
// wait for all tasks to complete
for (Future<?> future : futures) {
future.get();
}
assertTrue(Ordering.<Integer>natural().isOrdered(executions), executions.toString());
executor.shutdown();
}
private static class MeetingPoint
{
private final CountDownLatch arrived = new CountDownLatch(1);
private final CountDownLatch readyForNextPhase = new CountDownLatch(1);
public void waitForNextPhase()
throws InterruptedException
{
arrived.countDown();
readyForNextPhase.await();
}
public void waitForArrival()
throws InterruptedException
{
arrived.await();
}
public void notifyAdvance()
{
readyForNextPhase.countDown();
}
}
private static Callable<Void> newTask(int group, Queue<Integer> executions)
{
return newTask(group, null, executions);
}
private static Callable<Void> newTask(final int group, final MeetingPoint meetingPoint, final Queue<Integer> executions)
{
return new Callable<Void>()
{
@Override
public Void call()
{
executions.add(group);
if (meetingPoint != null) {
try {
meetingPoint.waitForNextPhase();
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw Throwables.propagate(e);
}
}
return null;
}
};
}
}