org.sapia.ubik.net
Class ThreadPool

java.lang.Object
  org.sapia.ubik.net.Pool
      org.sapia.ubik.net.ThreadPool

Direct Known Subclasses:

SocketRmiServerThreadPool

public abstract class ThreadPool
extends Pool

A pool of PooledThread instances. Inheriting classes must implement the newThread() method, which must return an application-specific PooledThread instance.

Applications must use the pool in the following manner:

 PooledThread thread = (PooledThread)threadPool.acquire();

 thread.exec(someData);

 

Upon the exec() method being called, the thread immediately:

• calls its own doExec method;
• releases itself to its "owning" pool after the doExec() method returns.

Thus, applications need not be concerned about returning the passed in thread to the pool.

Author:

Yanick Duchesne

Copyright:

Copyright © 2002-2003 Sapia Open Source Software. All Rights Reserved.

License:

Read the license.txt file of the jar or visit the license page at the Sapia OSS web site

See Also:

PooledThread, PooledThread.doExec(Object)

Field Summary

Fields inherited from class org.sapia.ubik.net.Pool

_currentCount, _lastUsageTime, _maxSize, _objects, NO_MAX, NO_TIME_OUT

Constructor Summary

protected	ThreadPool(java.lang.String name, boolean daemon) Creates a thread pool.
protected	ThreadPool(java.lang.String name, boolean daemon, int maxSize) Creates a thread pool.

Method Summary

void	disableStats() Disables statistics
protected java.lang.Object	doNewObject() This template method should be overridden by inheriting classes to provide object instances that will be pooled.
void	enabledStats() Enables statistics
Statistic	getDurationStat()
Statistic	getRpsStat()
int	getThreadCount()
protected abstract PooledThread	newThread() This method must be overridden by inheriting classes; the returned thread must not be started by this method; the pool implements this behavior.
protected java.lang.Object	onAcquire(java.lang.Object o)
protected void	onRelease(java.lang.Object o)
void	shutdown() Cleanly shuts down this instance.
void	shutdown(long timeout) Cleanly shuts down this instance; internally busy threads are interrupted - currently executing threads finish their task before termination.

Methods inherited from class org.sapia.ubik.net.Pool

acquire, acquire, acquireCreate, cleanup, fill, getCreatedCount, getLastUsageTime, release, shrinkTo, size

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadPool

protected ThreadPool(java.lang.String name,
                     boolean daemon,
                     int maxSize)

Creates a thread pool.

Parameters:

name - the name of the threads that will be created (to distinguish among the different threads, a counter is appended to the name for each thread).

daemon - if true, the threads created by this pool will be set as daemon.

maxSize - the maximum number of threads that this pool creates.

ThreadPool

protected ThreadPool(java.lang.String name,
                     boolean daemon)

Creates a thread pool.

Parameters:

name - the name of the threads that will be created (to distinguish among the different threads, a counter is appended to the name for each thread).

daemon - if true, the threads created by this pool will be set as daemon.

Method Detail

onAcquire

protected java.lang.Object onAcquire(java.lang.Object o)
                              throws java.lang.Exception,
                                     java.lang.IllegalStateException

Overrides:

onAcquire in class Pool

Throws:

java.lang.IllegalStateException - if this instance is shutting down or is shut down.

java.lang.Exception

See Also:

Pool.onAcquire(Object)

onRelease

protected void onRelease(java.lang.Object o)

Overrides:

onRelease in class Pool

See Also:

Pool.onRelease(Object)

getRpsStat

public Statistic getRpsStat()

Returns:

this instance's requests-per-second stat.

getDurationStat

public Statistic getDurationStat()

Returns:

enabledStats

public void enabledStats()

Enables statistics

disableStats

public void disableStats()

Disables statistics

shutdown

public void shutdown()

Cleanly shuts down this instance.

See Also:

shutdown(long)

getThreadCount

public int getThreadCount()

Returns:

the number of active threads in this instance.

shutdown

public void shutdown(long timeout)

Cleanly shuts down this instance; internally busy threads are interrupted - currently executing threads finish their task before termination.

This method waits that all threads are finished before it returns, OR until the given timeout is reached.

Parameters:

timeout - a shutdown timeout - this method will return when this timeout is reached, even if some threads are still executing.

doNewObject

protected final java.lang.Object doNewObject()
                                      throws java.lang.Exception

Description copied from class: Pool

This template method should be overridden by inheriting classes to provide object instances that will be pooled.

Specified by:

doNewObject in class Pool

Returns:

an Object to pool.

Throws:

java.lang.Exception - if an error occurs while creating the object to be returned.

See Also:

Pool.doNewObject()

newThread

protected abstract PooledThread newThread()
                                   throws java.lang.Exception

This method must be overridden by inheriting classes; the returned thread must not be started by this method; the pool implements this behavior.

Returns:

a PooledThread instance.

Throws:

java.lang.Exception