com.bigdata.util.concurrent

Class LatchedExecutor

java.lang.Object

com.bigdata.util.concurrent.LatchedExecutor

All Implemented Interfaces:

Executor

public class LatchedExecutor
extends Object
implements Executor

A fly weight helper class that runs tasks either sequentially or with limited parallelism against some thread pool. Deadlock can arise when limited parallelism is applied if there are dependencies among the tasks. Limited parallelism is enforced using a counting Semaphore. New tasks can start iff the latch is non-zero. The maximum parallelism is the minimum of the value specified to the constructor and the potential parallelism of the delegate service.

Note: The pattern for running tasks on this service is generally to execute(Runnable) a Runnable and to make that Runnable a FutureTask if you want to await the Future of a Runnable or Callable or otherwise manage its execution.

Note: This class can NOT be trivially wrapped as an ExecutorService since the resulting delegation pattern for submit() winds up invoking execute() on the delegate ExecutorService rather than on this class.

Author:

Bryan Thompson

Constructor Summary

Constructors

Constructor and Description
LatchedExecutor(Executor executor, int nparallel)

Method Summary

Methods

Modifier and Type	Method and Description
void	execute(Runnable r)
int	getNParallel() Return the maximum parallelism allowed by this Executor.

Methods inherited from class java.lang.Object

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

Constructor Detail

LatchedExecutor

public LatchedExecutor(Executor executor,
               int nparallel)

Method Detail

getNParallel

public int getNParallel()

Return the maximum parallelism allowed by this Executor.

execute

public void execute(Runnable r)

Specified by:

execute in interface Executor