/*
* Copyright (C) 2009 eXo Platform SAS.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.exoplatform.services.jcr.impl.proccess;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
/**
* WorkerService.
*
* @author <a href="mailto:karpenko.sergiy@gmail.com">Karpenko Sergiy</a>
* @version $Id: WorkerService.java 34361 2010-08-24 23:58:59Z aheritier $
*/
public class WorkerService
{
/**
* Executor that process assigned command periodically.
*/
private final ScheduledThreadPoolExecutor executor;
static class WorkerThreadFactory implements ThreadFactory
{
static final AtomicInteger poolNumber = new AtomicInteger(1);
final ThreadGroup group;
final AtomicInteger threadNumber = new AtomicInteger(1);
final String namePrefix;
final boolean isDaemon;
WorkerThreadFactory(String namePrefix)
{
this(namePrefix, false);
}
WorkerThreadFactory(String namePrefix, boolean isDaemon)
{
this.isDaemon = isDaemon;
SecurityManager s = System.getSecurityManager();
group = (s != null) ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
this.namePrefix =
(namePrefix == null || namePrefix.isEmpty()) ? "pool-" + poolNumber.getAndIncrement() + "-thread-"
: namePrefix + " ";
}
public Thread newThread(Runnable r)
{
Thread t = new Thread(group, r, namePrefix + threadNumber.getAndIncrement(), 0);
t.setDaemon(isDaemon);
if (t.getPriority() != Thread.NORM_PRIORITY)
t.setPriority(Thread.NORM_PRIORITY);
return t;
}
}
/**
* Constructor.
*
* @param threadCount - max thread count that executor may use
*/
public WorkerService(int threadCount)
{
this(threadCount, null);
}
/**
* Constructor.
*
* @param threadCount - max thread count that executor may use
* @param threadNamePrefix - thread name prefix
*/
public WorkerService(int threadCount, String threadNamePrefix)
{
this(threadCount, threadNamePrefix, true);
}
/**
* Constructor.
*
* @param threadCount - max thread count that executor may use
* @param threadNamePrefix - thread name prefix
* @param makeThreadsDaemon - does thread created by Service must be daemon
*/
public WorkerService(int threadCount, String threadNamePrefix, boolean makeThreadsDaemon)
{
executor =
new ScheduledThreadPoolExecutor(threadCount, new WorkerThreadFactory(threadNamePrefix, makeThreadsDaemon));
}
/**
* Execute specified <code>command</code> periodically with <code>delay</code>.
*
* @param command - command that must be executed
* @param delay - delay between each command execution
* @return
*/
public ScheduledFuture<?> executePeriodically(Runnable command, long delay)
{
return executor.scheduleWithFixedDelay(command, 0, delay, TimeUnit.MILLISECONDS);
}
/**
* Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted.
*/
public void stop()
{
executor.shutdown();
}
}