net.spy.util
Class ThreadPoolManager

java.lang.Object
  java.lang.Thread
      net.spy.SpyThread
          net.spy.util.LoopingThread
              net.spy.util.ThreadPoolManager

All Implemented Interfaces:

java.lang.Runnable

public class ThreadPoolManager
extends LoopingThread

Management thread for managing a ThreadPool. This thread basically gets to hear about everything that's going on and can make the decision to spawn more threads, or kill some off if necessary.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class net.spy.util.LoopingThread

DEFAULT_MS_PER_LOOP

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

ThreadPoolManager(java.lang.ThreadGroup tg)
Get an instance of ThreadPoolManager.

Method Summary

protected void	checkTooFewThreads() Check to see if there are too few threads to handle the current work load.
protected void	checkTooManyThreads() Check to see if there are too many idle threads.
protected ThreadPool	getThreadPool() Get the ThreadPool we're watching.
protected void	runLoop() Check to see if we should start up or shut down any threads.
void	setThreadPool(ThreadPool t) Set the ThreadPool to watch.
void	start() Initialize this ThreadPoolManager.

Methods inherited from class net.spy.util.LoopingThread

getMsPerLoop, performDelay, requestStop, run, setMsPerLoop

Methods inherited from class net.spy.SpyThread

getLogger

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadPoolManager

public ThreadPoolManager(java.lang.ThreadGroup tg)

Get an instance of ThreadPoolManager.

Parameters:

tg - the thread group in which the pool manager will exist

Method Detail

getThreadPool

protected ThreadPool getThreadPool()

Get the ThreadPool we're watching.

setThreadPool

public final void setThreadPool(ThreadPool t)

Set the ThreadPool to watch.

start

public void start()

Initialize this ThreadPoolManager.

Overrides:

start in class java.lang.Thread

checkTooFewThreads

protected void checkTooFewThreads()

Check to see if there are too few threads to handle the current work load. If the number of idle threads is below the minIdleThreads from the ThreadPool, but not greater than maxTotalThreads, we can spin some more threads up.

checkTooManyThreads

protected void checkTooManyThreads()

Check to see if there are too many idle threads. If the number of idle threads is above minIdleThreads, we can request to kill some off here.

The shutdown should be slow, no more than one thread per loop.

runLoop

protected void runLoop()

Check to see if we should start up or shut down any threads.

Specified by:

runLoop in class LoopingThread