org.jboss.util.threadpool
Class MinPooledExecutor

java.lang.Object
  PooledExecutor
      org.jboss.util.threadpool.MinPooledExecutor

public class MinPooledExecutor

extends PooledExecutor

A pooled executor where the minimum pool size threads are kept alive. This is needed in order for the waitWhenBlocked option to work because of a race condition inside the Executor. The race condition goes something like: RT - Requesting Thread wanting to use the pool LT - Last Thread in the pool RT: Check there are enough free threads to process, yes LT is there, so no need to create a new thread. LT: Times out on the keep alive, LT is destroyed. RT: Try to execute, blocks because there are no available threads. In fact, the pool is now empty which the executor mistakenly inteprets as all of them being in use. Doug Lea says he isn't going to fix. In fact, the version in j2se 1.5 doesn't have this option. In order for this to work, the min pool size must be > 0.

See Also:

Serialized Form

keepAliveSize

protected int keepAliveSize

The number of threads to keep alive threads

MinPooledExecutor

public MinPooledExecutor(int poolSize)

Construct a new executor

Parameters:

poolSize - the minimum pool size

MinPooledExecutor

public MinPooledExecutor(Channel channel,
                         int poolSize)

Construct a new executor

Parameters:

channel - the queue for any requests

poolSize - the minimum pool size

getKeepAliveSize

public int getKeepAliveSize()

Returns:

the number of threads to keep alive

setKeepAliveSize

public void setKeepAliveSize(int keepAliveSize)

Parameters:

keepAliveSize - the number of threads to keep alive

getTask

protected java.lang.Runnable getTask()
                              throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

keepAlive

protected boolean keepAlive()

We keep alive unless we are told to shutdown or there are more than keepAliveSize threads in the pool

Returns:

whether to keep alive