org.mortbay.thread
Class BoundedThreadPool

java.lang.Object
  org.mortbay.component.AbstractLifeCycle
      org.mortbay.thread.BoundedThreadPool

All Implemented Interfaces:

Serializable, LifeCycle, ThreadPool

Direct Known Subclasses:

IO

public class BoundedThreadPool
extends AbstractLifeCycle
implements Serializable, ThreadPool

A pool of threads.

Avoids the expense of thread creation by pooling threads after their run methods exit for reuse.

If the maximum pool size is reached, jobs wait for a free thread. By default there is no maximum pool size. Idle threads timeout and terminate until the minimum number of threads are running.

Author:

Greg Wilkins , Juancarlo Anez

See Also:

Serialized Form

Nested Class Summary

class

BoundedThreadPool.PoolThread Pool Thread class.

Field Summary

private static int	__id
private List	_blocked
private int	_blockMs
private boolean	_daemon
private int	_id
private List	_idle
private String	_joinLock
private String	_lock
private int	_maxIdleTimeMs
private int	_maxThreads
private int	_minThreads
private String	_name
(package private) int	_priority
private Set	_threads
private boolean	_warned
private static long	serialVersionUID

Constructor Summary

BoundedThreadPool()

Method Summary

boolean	dispatch(Runnable job) Run job.
protected void	doStart()
protected void	doStop() Stop the BoundedThreadPool.
int	getIdleThreads() Get the number of idle threads in the pool.
int	getMaxIdleTimeMs() Get the maximum thread idle time.
int	getMaxThreads() Set the maximum number of threads.
int	getMinThreads() Get the minimum number of threads.
String	getName()
int	getThreads() Get the number of threads in the pool.
int	getThreadsPriority() Get the priority of the pool threads.
boolean	isDaemon() Delegated to the named or anonymous Pool.
void	join()
protected void	newThread()
void	setDaemon(boolean daemon) Delegated to the named or anonymous Pool.
void	setMaxIdleTimeMs(int maxIdleTimeMs) Set the maximum thread idle time.
void	setMaxThreads(int maxThreads) Set the maximum number of threads.
void	setMinThreads(int minThreads) Set the minimum number of threads.
void	setName(String name)
void	setThreadsPriority(int priority) Set the priority of the pool threads.
protected void	stopJob(Thread thread, Object job) Stop a Job.

Methods inherited from class org.mortbay.component.AbstractLifeCycle

isFailed, isRunning, isStarted, isStarting, isStopping, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.mortbay.component.LifeCycle

isFailed, isRunning, isStarted, isStarting, isStopping, start, stop

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

__id

private static int __id

_blocked

private transient List _blocked

_blockMs

private int _blockMs

_daemon

private boolean _daemon

_id

private transient int _id

_lock

private final String _lock

See Also:

Constant Field Values

_joinLock

private final String _joinLock

See Also:

Constant Field Values

_maxIdleTimeMs

private int _maxIdleTimeMs

_maxThreads

private int _maxThreads

_minThreads

private int _minThreads

_name

private String _name

_priority

int _priority

_threads

private Set _threads

_idle

private List _idle

_warned

private boolean _warned

Constructor Detail

BoundedThreadPool

public BoundedThreadPool()

Method Detail

getIdleThreads

public int getIdleThreads()

Get the number of idle threads in the pool.

Specified by:

getIdleThreads in interface ThreadPool

Returns:

Number of threads

See Also:

getThreads()

getMaxIdleTimeMs

public int getMaxIdleTimeMs()

Get the maximum thread idle time. Delegated to the named or anonymous Pool.

Returns:

Max idle time in ms.

See Also:

setMaxIdleTimeMs(int)

getMaxThreads

public int getMaxThreads()

Set the maximum number of threads. Delegated to the named or anonymous Pool.

Returns:

maximum number of threads.

See Also:

setMaxThreads(int)

getMinThreads

public int getMinThreads()

Get the minimum number of threads. Delegated to the named or anonymous Pool.

Returns:

minimum number of threads.

See Also:

setMinThreads(int)

getName

public String getName()

Returns:

The name of the BoundedThreadPool.

getThreads

public int getThreads()

Get the number of threads in the pool.

Specified by:

getThreads in interface ThreadPool

Returns:

Number of threads

See Also:

getIdleThreads()

getThreadsPriority

public int getThreadsPriority()

Get the priority of the pool threads.

Returns:

the priority of the pool threads.

isDaemon

public boolean isDaemon()

Delegated to the named or anonymous Pool.

join

public void join()
          throws InterruptedException

Specified by:

join in interface ThreadPool

Throws:

InterruptedException

newThread

protected void newThread()

dispatch

public boolean dispatch(Runnable job)

Run job.

Specified by:

dispatch in interface ThreadPool

Returns:

true if the job was given to a thread, false if no thread was available.

setDaemon

public void setDaemon(boolean daemon)

Delegated to the named or anonymous Pool.

setMaxIdleTimeMs

public void setMaxIdleTimeMs(int maxIdleTimeMs)

Set the maximum thread idle time. Threads that are idle for longer than this period may be stopped. Delegated to the named or anonymous Pool.

Parameters:

maxIdleTimeMs - Max idle time in ms.

See Also:

getMaxIdleTimeMs()

setMaxThreads

public void setMaxThreads(int maxThreads)

Set the maximum number of threads. Delegated to the named or anonymous Pool.

Parameters:

maxThreads - maximum number of threads.

See Also:

getMaxThreads()

setMinThreads

public void setMinThreads(int minThreads)

Set the minimum number of threads. Delegated to the named or anonymous Pool.

Parameters:

minThreads - minimum number of threads

See Also:

getMinThreads()

setName

public void setName(String name)

Parameters:

name - Name of the BoundedThreadPool to use when naming Threads.

setThreadsPriority

public void setThreadsPriority(int priority)

Set the priority of the pool threads.

Parameters:

priority - the new thread priority.

doStart

protected void doStart()
                throws Exception

Overrides:

doStart in class AbstractLifeCycle

Throws:

Exception

doStop

protected void doStop()
               throws Exception

Stop the BoundedThreadPool. New jobs are no longer accepted,idle threads are interrupted and stopJob is called on active threads. The method then waits min(getMaxStopTimeMs(),getMaxIdleTimeMs()), for all jobs to stop, at which time killJob is called.

Overrides:

doStop in class AbstractLifeCycle

Throws:

Exception

stopJob

protected void stopJob(Thread thread,
                       Object job)

Stop a Job. This method is called by the Pool if a job needs to be stopped. The default implementation does nothing and should be extended by a derived thread pool class if special action is required.

Parameters:

thread - The thread allocated to the job, or null if no thread allocated.

job - The job object passed to run.