Package org.apfloat.internal

Class ParallelRunnable

java.lang.Object

org.apfloat.internal.ParallelRunnable

All Implemented Interfaces:

Runnable

public abstract class ParallelRunnable
extends Object
implements Runnable

Abstract class for a Runnable that can be run in parallel by multiple threads. Internally, the ParallelRunnable splits the work to many small batches, which are run one at a time, and can be run in parallel by multiple threads. The ParallelRunnable isn't completed until all batches are completed, i.e. the run() method only returns when all batches are completed.

Since:

1.1

Version:

1.14.0

Author:

Mikko Tommila

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ParallelRunnable(long length)	Subclass constructor.

Method Summary

Modifier and Type	Method	Description
protected long	getPreferredBatchSize()	Get the preferred batch size.
protected Runnable	getRunnable(int startValue, int length)	Get the Runnable object for strides which fit in an int.
protected Runnable	getRunnable(long startValue, long length)	Get the Runnable object for strides which fit only in a long.
boolean	isWorkToBeCompleted()	Returns if there is some work that may be currently processed but not yet finished.
boolean	isWorkToBeStarted()	Returns if there is still enough work left to start a new batch.
final void	run()	Repeatedly get a batch of work and run it, until all batches are completed.
final boolean	runBatch()	Run one batch if available.

Methods inherited from class java.lang.Object

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

Constructor Details

ParallelRunnable

protected ParallelRunnable(long length)

Subclass constructor.

Parameters:

length - The length of the work to be run.

Method Details

run

public final void run()

Repeatedly get a batch of work and run it, until all batches are completed. This method can (and should) be called from multiple threads in parallel.

Specified by:

run in interface Runnable

runBatch

public final boolean runBatch()

Run one batch if available. Returns true if a batch was actually acquired and run, false if all batches were already started and none could be run. This method can be used by any thread to steal and complete a minimal amount of work.

Note that if a batch could not be run, it does not mean that all of the batches are already completed - some could still be running.

Returns:

If a batch was actually run.

isWorkToBeStarted

public boolean isWorkToBeStarted()

Returns if there is still enough work left to start a new batch.

Returns:

If a new batch could be started to still perform some work.

Since:

1.9.0

isWorkToBeCompleted

public boolean isWorkToBeCompleted()

Returns if there is some work that may be currently processed but not yet finished.

Returns:

If there is still some work left that is not completed yet.

Since:

1.9.0

getRunnable

protected Runnable getRunnable(int startValue,
 int length)

Get the Runnable object for strides which fit in an int.

Parameters:

startValue - The starting value for the stride.

length - The length of the stride.

Returns:

The Runnable object for the specified stride.

getRunnable

protected Runnable getRunnable(long startValue,
 long length)

Get the Runnable object for strides which fit only in a long.

Parameters:

startValue - The starting value for the stride.

length - The length of the stride.

Returns:

The Runnable object for the specified stride.

getPreferredBatchSize

protected long getPreferredBatchSize()

Get the preferred batch size.

Returns:

The preferred batch size.

Since:

1.7.0