com.avaje.ebeaninternal.server.lib.thread

Class ThreadPool

java.lang.Object

com.avaje.ebeaninternal.server.lib.thread.ThreadPool

public class ThreadPool
extends Object

This is a pool of threads which can be assigned work.

The Pool will automatically grow as required up to its maximum pool size. The Pool will be automatically shrink by trimming threads that have been idle for some time.

Constructor Summary

Constructors

Constructor and Description
ThreadPool(String poolName, boolean isDaemon, Integer threadPriority) Create the ThreadPool.
ThreadPool(String poolName, boolean isDaemon, Integer threadPriority, int minSize, int maxSize, long maxIdleMillis)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	assign(Runnable work, boolean addToQueueIfFull) Assign a task to the thread pool, specifing the options to wait or queue the task if the pool is fully busy and can't grow.
static ThreadPool	createThreadPool(String poolName) Create and return a ThreadPool reading configuration from GlobalProperties.
int	getBusyCount() Return the number of currently busy threads.
PooledThread	getBusyThread(String threadName) Find a thread using its name from the busy list.
Iterator<PooledThread>	getBusyThreads() Return an Iterator of PooledThread that are currently running.
long	getMaxIdleTime() Return the maximum amount of time in millis that Threads can be idle before they are trimmed.
int	getMaxSize() Return the maximum size this pool can grow to.
int	getMinSize() Return the minimum size the pool should maintain.
String	getName() Return the name of the thread pool.
PooledThread	interrupt(String threadName) Interrupt a named thread that is currently busy.
boolean	isStopping() Return true if the pool is shutting down.
protected void	maintainPoolSize() Trim or grow the pool leaving at least min free.
protected void	removeThread(PooledThread thread) Remove the thread from the pool.
protected void	returnThread(PooledThread thread) fired when a Thread from the pool has finished, and can be put back into the pool.
void	setMaxIdleTime(long maxIdleTime) Set the maxiumium amount of time in millis that Threads can be idle before they are trimed.
void	setMaxSize(int maxSize) Set the maximum size the pool should grow to.
void	setMinSize(int minSize) Set the minimum size the pool should try to maintain.
void	shutdown() Shutdown the threadpool stopping all the threads.
int	size() Return the total number of busy and free threads in the pool.

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadPool

public ThreadPool(String poolName,
          boolean isDaemon,
          Integer threadPriority,
          int minSize,
          int maxSize,
          long maxIdleMillis)

ThreadPool

public ThreadPool(String poolName,
          boolean isDaemon,
          Integer threadPriority)

Create the ThreadPool.

Method Detail

createThreadPool

public static ThreadPool createThreadPool(String poolName)

Create and return a ThreadPool reading configuration from GlobalProperties.

isStopping

public boolean isStopping()

Return true if the pool is shutting down.

getName

public String getName()

Return the name of the thread pool.

setMinSize

public void setMinSize(int minSize)

Set the minimum size the pool should try to maintain.

getMinSize

public int getMinSize()

Return the minimum size the pool should maintain.

setMaxSize

public void setMaxSize(int maxSize)

Set the maximum size the pool should grow to.

getMaxSize

public int getMaxSize()

Return the maximum size this pool can grow to.

size

public int size()

Return the total number of busy and free threads in the pool.

getBusyCount

public int getBusyCount()

Return the number of currently busy threads.

assign

public boolean assign(Runnable work,
             boolean addToQueueIfFull)

Assign a task to the thread pool, specifing the options to wait or queue the task if the pool is fully busy and can't grow.

When the pool is fully busy...

addToQueue=true -> work is added to queue, returns false
addToQueue=false -> work is not done or queued, returns false

Parameters:

work - the runnable work to do.

addToQueueIfFull - If the pool is maxed out and this is true then it queues the Runnable.

removeThread

protected void removeThread(PooledThread thread)

Remove the thread from the pool. The thread should be stopped before it is removed.

returnThread

protected void returnThread(PooledThread thread)

fired when a Thread from the pool has finished, and can be put back into the pool.

getBusyThreads

public Iterator<PooledThread> getBusyThreads()

Return an Iterator of PooledThread that are currently running. You should only use this for display. Use the getPooledThread() or interrupt() methods to interrupt a particular thread.

Returns:

an Iterator of busy PooledThread's.

shutdown

public void shutdown()

Shutdown the threadpool stopping all the threads. This will wait until any busy threads have finished their assigned work.

maintainPoolSize

protected void maintainPoolSize()

Trim or grow the pool leaving at least min free.

interrupt

public PooledThread interrupt(String threadName)

Interrupt a named thread that is currently busy.

Returns the thread that was interrupted or null if the thread was not found. If the thread was interrupted then it will automatically be stopped and removed from the pool.

Note that it may take some time to actually interrupt the thread so an immediate test to see if the thread stopped will probably be wrong.

 
 ThreadPool test = ThreadPoolManager.getThreadPool("test");
 PooledThread pt = test.interrupt("test.1");
 if (pt == null) {
      // the thread was not found, perhaps finished?
 } else {
      // give interrupt a little time to execute
      Thread.sleep(1000);
      boolean hasStopped = pt.isStopped();
      //..
 }
 
 

Returns:

the thread that was interrupted

getBusyThread

public PooledThread getBusyThread(String threadName)

Find a thread using its name from the busy list. Returns null if the thread is not found in the busy list.

getMaxIdleTime

public long getMaxIdleTime()

Return the maximum amount of time in millis that Threads can be idle before they are trimmed.

setMaxIdleTime

public void setMaxIdleTime(long maxIdleTime)

Set the maxiumium amount of time in millis that Threads can be idle before they are trimed.