org.directwebremoting.dwrp.ShutdownAlarm Maven / Gradle / Ivy
/*
* Copyright 2005 Joe Walker
*
* 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 org.directwebremoting.dwrp;
import org.directwebremoting.extend.ServerLoadMonitor;
import org.directwebremoting.extend.WaitController;
/**
* An Alarm that allows the system to close all connections when it is shutting
* down.
* WARNING: This code has a non-obvious side effect - The server load
* monitor (which hands out shutdown messages) also monitors usage by looking
* at the number of connected alarms.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class ShutdownAlarm extends BasicAlarm implements Alarm
{
/**
* Register ourselves with the ServerLoadMonitor so we can raise an
* Alarm if we get shutdown
* @param serverLoadMonitor
*/
public ShutdownAlarm(ServerLoadMonitor serverLoadMonitor)
{
this.serverLoadMonitor = serverLoadMonitor;
}
/* (non-Javadoc)
* @see org.directwebremoting.dwrp.PollHandler.Alarm#setAlarmAction(org.directwebremoting.dwrp.PollHandler.Sleeper)
*/
public void setAlarmAction(Sleeper sleeper)
{
serverLoadMonitor.threadWaitStarting(waitController);
super.setAlarmAction(sleeper);
}
/* (non-Javadoc)
* @see org.directwebremoting.dwrp.PollHandler.Alarm#cancel()
*/
public void cancel()
{
serverLoadMonitor.threadWaitEnding(waitController);
super.cancel();
}
/**
* The listener to allow the ServerLoadMonitor to shut us down
*/
private WaitController waitController = new WaitController()
{
/* (non-Javadoc)
* @see org.directwebremoting.extend.WaitController#shutdown()
*/
public void shutdown()
{
raiseAlarm();
shutdown = true;
}
/* (non-Javadoc)
* @see org.directwebremoting.extend.WaitController#isShutdown()
*/
public boolean isShutdown()
{
return shutdown;
}
/**
* We neeed to be able to say if we have been shutdown
*/
boolean shutdown = false;
};
/**
* The source of shutdown messages
*/
protected ServerLoadMonitor serverLoadMonitor;
}