org.knowceans.util
Class ParallelFor

java.lang.Object
  org.knowceans.util.ParallelFor

public abstract class ParallelFor
extends java.lang.Object

ParallelFor implements what in OpenMP is called a parallel for loop, i.e., a loop that executes in parallel on several threads with a barrier (join) at the end. Implementors simply subclass and implement the process() method and make sure the loop() method is not called while a loop of one instance is running. Execution can be stopped using stop(), which completes the iterations currently running. After the last usage of the class, it should be shut down properly using function shutdown() or the hard way using System.exit();

Author:

gregor

Constructor Summary

ParallelFor()
instantiate with as many threads as there are processors

ParallelFor(int nthreads)
instantiate a parallel for implementation

Method Summary

void	loop(int N) Start worker threads and loop through the iterations.
void	loopOnce(int N) loops once, then shuts down
static void	main(java.lang.String[] args)
abstract void	process(int iteration, int thread) payload for the for loop
void	shutdown() shut down the thread pool after final usage
void	stop() stop loop execution

Methods inherited from class java.lang.Object

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

Constructor Detail

ParallelFor

public ParallelFor()

instantiate with as many threads as there are processors

ParallelFor

public ParallelFor(int nthreads)

instantiate a parallel for implementation

Method Detail

loop

public void loop(int N)

Start worker threads and loop through the iterations. Should never be called while the loop instance is still running.

Parameters:

N -

loopOnce

public void loopOnce(int N)

loops once, then shuts down

Parameters:

N -

process

public abstract void process(int iteration,
                             int thread)

payload for the for loop

Parameters:

iteration - in the for loop

thread - on the machine

stop

public void stop()

stop loop execution

shutdown

public void shutdown()

shut down the thread pool after final usage

main

public static void main(java.lang.String[] args)