/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
*
* This library 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 library 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.
*
* For further information about Alkacon Software GmbH, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.scheduler;
import org.opencms.main.CmsLog;
import org.apache.commons.logging.Log;
/**
* A worker thread for the OpenCms scheduler.<p>
*
* @since 6.0.0
*/
public class CmsSchedulerThread extends Thread {
/** The log object for this class. */
private static final Log LOG = CmsLog.getLog(CmsSchedulerThread.class);
/** The scheduler thread pool this thread belongs to. */
private CmsSchedulerThreadPool m_pool;
/** A flag that signals the thread to terminate. */
private boolean m_run;
/** A runnable class. */
private Runnable m_runnable;
/**
* Create a scheduler thread that runs continuosly,
* waiting for new runnables to be provided by the scheduler thread pool.<p>
*
* @param pool the pool to use
* @param threadGroup the thread group to use
* @param threadName the name for the thread
* @param prio the priority of the thread
* @param isDaemon controls if this should be a deamon thread or not
*/
CmsSchedulerThread(
CmsSchedulerThreadPool pool,
ThreadGroup threadGroup,
String threadName,
int prio,
boolean isDaemon) {
this(pool, threadGroup, threadName, prio, isDaemon, null);
}
/**
* Create a scheduler thread that runs the specified runnable exactly once.<p>
*
* @param pool the pool to use
* @param threadGroup the thread group to use
* @param threadName the name for the thread
* @param prio the priority of the thread
* @param isDaemon controls if this should be a deamon thread or not
* @param runnable the runnable to run
*/
CmsSchedulerThread(
CmsSchedulerThreadPool pool,
ThreadGroup threadGroup,
String threadName,
int prio,
boolean isDaemon,
Runnable runnable) {
super(threadGroup, threadName);
m_run = true;
m_pool = pool;
m_runnable = runnable;
setPriority(prio);
setDaemon(isDaemon);
}
/**
* Loop, executing targets as they are received.<p>
*/
@Override
public void run() {
boolean runOnce = (m_runnable != null);
while (m_run) {
setPriority(m_pool.getThreadPriority());
try {
if (m_runnable == null) {
m_runnable = m_pool.getNextRunnable();
}
if (m_runnable != null) {
m_runnable.run();
}
} catch (InterruptedException e) {
LOG.error(Messages.get().getBundle().key(Messages.LOG_THREAD_INTERRUPTED_1, getName()), e);
} catch (Throwable t) {
LOG.error(Messages.get().getBundle().key(Messages.LOG_THREAD_ERROR_1, getName()), t);
} finally {
if (runOnce) {
m_run = false;
}
m_runnable = null;
}
}
if (LOG.isDebugEnabled()) {
LOG.debug(Messages.get().getBundle().key(Messages.LOG_THREAD_SHUTDOWN_1, getName()));
}
}
/**
* Signal the thread that it should terminate.<p>
*/
void shutdown() {
m_run = false;
}
}