/*
* Druid - a distributed column store.
* Copyright (C) 2012, 2013 Metamarkets Group Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package io.druid.concurrent;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
*/
public class Execs
{
public static ExecutorService singleThreaded(String nameFormat)
{
return Executors.newSingleThreadExecutor(makeThreadFactory(nameFormat));
}
public static ExecutorService multiThreaded(int threads, String nameFormat)
{
return Executors.newFixedThreadPool(threads, makeThreadFactory(nameFormat));
}
public static ScheduledExecutorService scheduledSingleThreaded(String nameFormat)
{
return Executors.newSingleThreadScheduledExecutor(makeThreadFactory(nameFormat));
}
public static ThreadFactory makeThreadFactory(String nameFormat)
{
return new ThreadFactoryBuilder().setDaemon(true).setNameFormat(nameFormat).build();
}
/**
* @param nameFormat nameformat for threadFactory
* @param capacity maximum capacity after which the executorService will block on accepting new tasks
* @return ExecutorService which blocks accepting new tasks when the capacity reached
*/
public static ExecutorService newBlockingSingleThreaded(final String nameFormat, final int capacity)
{
final BlockingQueue<Runnable> queue;
if (capacity > 0) {
queue = new ArrayBlockingQueue<>(capacity);
} else {
queue = new SynchronousQueue<>();
}
return new ThreadPoolExecutor(
1, 1, 0L, TimeUnit.MILLISECONDS, queue, makeThreadFactory(nameFormat),
new RejectedExecutionHandler()
{
@Override
public void rejectedExecution(Runnable r, ThreadPoolExecutor executor)
{
try {
executor.getQueue().put(r);
}
catch (InterruptedException e) {
throw new RejectedExecutionException("Got Interrupted while adding to the Queue");
}
}
}
);
}
}