Package ffx.potential.nonbonded

Class PairwiseSchedule

java.lang.Object

edu.rit.pj.Schedule

edu.rit.pj.IntegerSchedule

ffx.potential.nonbonded.PairwiseSchedule

public class PairwiseSchedule
extends IntegerSchedule

A fixed schedule that balances pairwise work across threads.

Since:

1.0

Author:

Michael J. Schnieders

Constructor Summary

Constructors

Constructor	Description
PairwiseSchedule(int nThreads, int nAtoms, Range[] ranges)	Constructor for PairwiseSchedule.

Method Summary

Modifier and Type	Method	Description
boolean	isFixedSchedule()	Determine if this schedule is a fixed schedule.
Range	next(int threadID)	Obtain the next chunk of iterations for the given thread index.
void	setAtoms(int nAtoms)	setAtoms.
void	start(int nThreads, Range chunkRange)	Start generating chunks of iterations for a parallel for loop using this schedule.

Methods inherited from class edu.rit.pj.IntegerSchedule

dynamic, dynamic, fixed, guided, guided, parse, runtime, runtime

Methods inherited from class java.lang.Object

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

Constructor Details

PairwiseSchedule

public PairwiseSchedule(int nThreads,
 int nAtoms,
 Range[] ranges)

Constructor for PairwiseSchedule.

Parameters:

nThreads - a int.

nAtoms - a int.

ranges - an array of Range objects.

Method Details

isFixedSchedule

public boolean isFixedSchedule()

Determine if this schedule is a fixed schedule. For a parallel team with K threads, a fixed schedule partitions the loop index range into exactly K chunks, one chunk for each thread, each chunk with predetermined upper and lower bounds.

This is a fixed schedule.

Specified by:

isFixedSchedule in class IntegerSchedule

Returns:

True if this is a fixed schedule, false otherwise.

next

public Range next(int threadID)

Obtain the next chunk of iterations for the given thread index. If there are more iterations, a range object is returned whose lower bound, upper bound, and stride specify the chunk of iterations to perform. The returned range object's stride is the same as that given to the start() method. The returned range object's lower bound and upper bound are contained within the range given to the start() method. If there are no more iterations, null is returned.

The next() method is called by multiple parallel team threads in the Parallel Java middleware. The next() method must be multiple thread safe.

Specified by:

next in class IntegerSchedule

Parameters:

threadID - Thread index in the range 0 .. K-1.

Returns:

Chunk of iterations, or null if no more iterations.

setAtoms

public void setAtoms(int nAtoms)

setAtoms.

Parameters:

nAtoms - a int.

start

public void start(int nThreads,
 Range chunkRange)

Start generating chunks of iterations for a parallel for loop using this schedule.

The start() method is only called by a single thread in the Parallel Java middleware.

Specified by:

start in class IntegerSchedule

Parameters:

nThreads - Number of threads in the parallel team.

chunkRange - Range of iterations for the entire parallel for loop. The stride may be 1 or greater.