org.eclipse.jetty.io.IdleTimeout Maven / Gradle / Ivy
Show all versions of ehcache Show documentation
//
// ========================================================================
// Copyright (c) 1995-2018 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.io;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicReference;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.thread.Scheduler;
/**
* An Abstract implementation of an Idle Timeout.
*
* This implementation is optimised that timeout operations are not cancelled on
* every operation. Rather timeout are allowed to expire and a check is then made
* to see when the last operation took place. If the idle timeout has not expired,
* the timeout is rescheduled for the earliest possible time a timeout could occur.
*/
public abstract class IdleTimeout
{
private static final Logger LOG = Log.getLogger(IdleTimeout.class);
private final Scheduler _scheduler;
private final AtomicReference _timeout = new AtomicReference<>();
private volatile long _idleTimeout;
private volatile long _idleTimestamp = System.currentTimeMillis();
private final Runnable _idleTask = new Runnable()
{
@Override
public void run()
{
long idleLeft = checkIdleTimeout();
if (idleLeft >= 0)
scheduleIdleTimeout(idleLeft > 0 ? idleLeft : getIdleTimeout());
}
};
/**
* @param scheduler A scheduler used to schedule checks for the idle timeout.
*/
public IdleTimeout(Scheduler scheduler)
{
_scheduler = scheduler;
}
public Scheduler getScheduler()
{
return _scheduler;
}
public long getIdleTimestamp()
{
return _idleTimestamp;
}
public long getIdleFor()
{
return System.currentTimeMillis() - getIdleTimestamp();
}
public long getIdleTimeout()
{
return _idleTimeout;
}
public void setIdleTimeout(long idleTimeout)
{
long old = _idleTimeout;
_idleTimeout = idleTimeout;
// Do we have an old timeout
if (old > 0)
{
// if the old was less than or equal to the new timeout, then nothing more to do
if (old <= idleTimeout)
return;
// old timeout is too long, so cancel it.
deactivate();
}
// If we have a new timeout, then check and reschedule
if (isOpen())
activate();
}
/**
* This method should be called when non-idle activity has taken place.
*/
public void notIdle()
{
_idleTimestamp = System.currentTimeMillis();
}
private void scheduleIdleTimeout(long delay)
{
Scheduler.Task newTimeout = null;
if (isOpen() && delay > 0 && _scheduler != null)
newTimeout = _scheduler.schedule(_idleTask, delay, TimeUnit.MILLISECONDS);
Scheduler.Task oldTimeout = _timeout.getAndSet(newTimeout);
if (oldTimeout != null)
oldTimeout.cancel();
}
public void onOpen()
{
activate();
}
private void activate()
{
if (_idleTimeout > 0)
_idleTask.run();
}
public void onClose()
{
deactivate();
}
private void deactivate()
{
Scheduler.Task oldTimeout = _timeout.getAndSet(null);
if (oldTimeout != null)
oldTimeout.cancel();
}
protected long checkIdleTimeout()
{
if (isOpen())
{
long idleTimestamp = getIdleTimestamp();
long idleTimeout = getIdleTimeout();
long idleElapsed = System.currentTimeMillis() - idleTimestamp;
long idleLeft = idleTimeout - idleElapsed;
if (LOG.isDebugEnabled())
LOG.debug("{} idle timeout check, elapsed: {} ms, remaining: {} ms", this, idleElapsed, idleLeft);
if (idleTimestamp != 0 && idleTimeout > 0)
{
if (idleLeft <= 0)
{
if (LOG.isDebugEnabled())
LOG.debug("{} idle timeout expired", this);
try
{
onIdleExpired(new TimeoutException("Idle timeout expired: " + idleElapsed + "/" + idleTimeout + " ms"));
}
finally
{
notIdle();
}
}
}
return idleLeft >= 0 ? idleLeft : 0;
}
return -1;
}
/**
* This abstract method is called when the idle timeout has expired.
*
* @param timeout a TimeoutException
*/
protected abstract void onIdleExpired(TimeoutException timeout);
/**
* This abstract method should be called to check if idle timeouts
* should still be checked.
*
* @return True if the entity monitored should still be checked for idle timeouts
*/
public abstract boolean isOpen();
}