org.jasig.portal.utils
Class ThreadPool

java.lang.Object
  java.lang.ThreadGroup
      org.jasig.portal.utils.ThreadPool

All Implemented Interfaces:

Thread.UncaughtExceptionHandler

public class ThreadPool
extends ThreadGroup

A thread pool implementation with a few extra kinks, such as ThreadPoolReceipt.

Version:

$Revision: 19776 $

Author:

Peter Kharchenko pkharchenko@interactivebusiness.com

Constructor Summary

ThreadPool(String name, ResourceLimits rl)

Method Summary

protected void	addNewWorker() Adds a new worker.
protected void	addWorker() Grow the size of the worker pool.
protected void	adjustSize(int newSize) Adjust the size of the worker pool.
void	clear() Clears all of the workers.
void	clearIdle() Clears all of the idle workers
ThreadPoolReceipt	execute(Runnable target)
protected void	killWorkerThread(ThreadPoolWorker pw)
protected void	notifyWorkerFinished(ThreadPoolWorker pw) Notifies the pool that a certain worker has finished.
protected void	notifyWorkerRestart(ThreadPoolWorker pw) Notifies the pool that a certain worker is done and wants to have a replacement started.
protected boolean	releaseWorker(ThreadPoolWorker worker) Signals the worker that it should quite as soon as a job (if any) is complete
protected void	stopWorker(ThreadPoolWorker worker) Signals the worker that it try to interrupt the current job and quit.
void	uncaughtException(Thread t, Throwable e) Handle the case when some worker crashes

Methods inherited from class java.lang.ThreadGroup

activeCount, activeGroupCount, allowThreadSuspension, checkAccess, destroy, enumerate, enumerate, enumerate, enumerate, getMaxPriority, getName, getParent, interrupt, isDaemon, isDestroyed, list, parentOf, resume, setDaemon, setMaxPriority, stop, suspend, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ThreadPool

public ThreadPool(String name,
                  ResourceLimits rl)

Method Detail

execute

public ThreadPoolReceipt execute(Runnable target)
                          throws InterruptedException

Throws:

InterruptedException

adjustSize

protected void adjustSize(int newSize)

Adjust the size of the worker pool. Adjustment is done by growing/shrinking the idle worker pool. Active workers will not be affected by this

addWorker

protected void addWorker()

Grow the size of the worker pool. This will "attempt" to add another worker, but unlike addNewWorker(), the resource limits are checked.

stopWorker

protected void stopWorker(ThreadPoolWorker worker)

Signals the worker that it try to interrupt the current job and quit.

releaseWorker

protected boolean releaseWorker(ThreadPoolWorker worker)

Signals the worker that it should quite as soon as a job (if any) is complete

Returns:

false if the worker has already been released

addNewWorker

protected void addNewWorker()

Adds a new worker. Doesn't check anything, just adds.

clearIdle

public void clearIdle()

Clears all of the idle workers

clear

public void clear()

Clears all of the workers.

uncaughtException

public void uncaughtException(Thread t,
                              Throwable e)

Handle the case when some worker crashes

Specified by:

uncaughtException in interface Thread.UncaughtExceptionHandler

Overrides:

uncaughtException in class ThreadGroup

notifyWorkerRestart

protected void notifyWorkerRestart(ThreadPoolWorker pw)

Notifies the pool that a certain worker is done and wants to have a replacement started.

killWorkerThread

protected void killWorkerThread(ThreadPoolWorker pw)

notifyWorkerFinished

protected void notifyWorkerFinished(ThreadPoolWorker pw)

Notifies the pool that a certain worker has finished.