/*
* NOTE: This copyright does *not* cover user programs that use HQ
* program services by normal system calls through the application
* program interfaces provided as part of the Hyperic Plug-in Development
* Kit or the Hyperic Client Development Kit - this is merely considered
* normal use of the program, and does *not* fall under the heading of
* "derived work".
*
* Copyright (C) [2004, 2005, 2006], Hyperic, Inc.
* This file is part of HQ.
*
* HQ is free software; you can redistribute it and/or modify
* it under the terms version 2 of the GNU General Public License as
* published by the Free Software Foundation. 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA.
*/
package org.hyperic.hq.product;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
class RunnableTrackThread implements Runnable {
private static Log log =
LogFactory.getLog(RunnableTrackThread.class.getName());
private Thread thread = null;
private static RunnableTrackThread instance = null;
private boolean shouldDie = false;
private long interval = TrackEventPluginManager.DEFAULT_INTERVAL;
private Set watchers =
Collections.synchronizedSet(new HashSet());
static synchronized RunnableTrackThread getInstance() {
if (instance == null) {
instance = new RunnableTrackThread();
}
return instance;
}
public synchronized void doStart() {
if (this.thread != null) {
return;
}
this.thread = new Thread(this, "RunnableLogThread");
this.thread.setDaemon(true);
this.thread.start();
log.info(this.thread.getName() + " started");
}
public synchronized void doStop() {
if (this.thread == null) {
return;
}
die();
this.thread.interrupt();
log.info(this.thread.getName() + " stopped");
this.thread = null;
}
public void setInterval(long interval) {
this.interval = interval;
}
public long getInterval() {
return this.interval;
}
public void add(Runnable watcher) {
this.watchers.add(watcher);
}
public void remove(Runnable watcher) {
this.watchers.remove(watcher);
}
public void run() {
while (!shouldDie) {
check();
try {
Thread.sleep(this.interval);
} catch (InterruptedException e) {
}
}
}
public void die() {
this.shouldDie = true;
}
public void check() {
synchronized (this.watchers) {
for (Iterator it = this.watchers.iterator();
it.hasNext();)
{
Runnable watcher = (Runnable)it.next();
try {
watcher.run();
} catch (Exception e) {
log.error("Unexpected exception: " + e, e);
}
}
}
}
}