com.quadrique.jbuildingblocks.core.thread
Class JbbThreadPool

java.lang.Object
  java.lang.ThreadGroup
      com.quadrique.jbuildingblocks.core.thread.JbbThreadPool

All Implemented Interfaces:

Thread.UncaughtExceptionHandler

public class JbbThreadPool
extends ThreadGroup

This class implements a thread pool. Thread pools are mainly used for thread intensive application. The main advantages of a thread pool is that you don't incur the cost of continuously creating/deleting threads and that you limit the number of possible threads. Typical usage: ThreadPool lPool = new ThreadPool(); lPool.execute( new Runnable() { public void run() { // execute this function on an existing // thread from the pool. ... } } ); The threads in the pool execute any given Runnable instance on a FIFO basis. The pool has an initial number of threads that are created upon startup. Based on the load, the number of threads either stays the same or is increased until the maximum number of threads is reached (in which case, the Runnable instances will be queued and executed as soon as the threads are released) The thread pool creates the threads in their own thread group.

Field Summary

static int

MAX_NB_OF_THREADS constants

Method Summary

void	execute(Runnable zTarget) The run() method of the given Runnable object will be executed by one of the threads of the pool.
int	getCurrentNbOfThreadsInPool()
int	getMaxNbOfThreadsReachedInPool()
static JbbThreadPool	newInstance(String zName, int zInitialNbOfThreads, int zMaxNbOfThreads)
void	shutdown(long zMaxMilliSeconds) Stops the execution of the thread pool including its associated threads (if a thread is currently executing a Runnable instance, it will stop as soon as the run() method returns).

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, uncaughtException

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

MAX_NB_OF_THREADS

public static final int MAX_NB_OF_THREADS

constants

See Also:

Constant Field Values

Method Detail

newInstance

public static JbbThreadPool newInstance(String zName,
                                        int zInitialNbOfThreads,
                                        int zMaxNbOfThreads)
                                 throws Exception

Throws:

Exception

execute

public final void execute(Runnable zTarget)

The run() method of the given Runnable object will be executed by one of the threads of the pool. Please note that if the thread pool is shutting down, this method returns immediately without executing the target.

Parameters:

zTarget - the runnable instance to execute

Throws:

JbbShuttingDownException - if you try to execute a method while the thread pool is shutting down

shutdown

public final void shutdown(long zMaxMilliSeconds)

Stops the execution of the thread pool including its associated threads (if a thread is currently executing a Runnable instance, it will stop as soon as the run() method returns). If there is still some Runnable instances in the internal queue, they will be discarded

Parameters:

zMaxMilliSeconds - the maximum amount of time to wait for all the threads to be stopped

getCurrentNbOfThreadsInPool

public final int getCurrentNbOfThreadsInPool()

Returns:

the current number of threads in the pool

getMaxNbOfThreadsReachedInPool

public final int getMaxNbOfThreadsReachedInPool()

Returns:

the current number of threads in the pool