pu.pi

Class ParIteratorAbstract<E>

java.lang.Object

pu.pi.ParIteratorAbstract<E>

All Implemented Interfaces:

java.util.Iterator<E>, ParIterator<E>

Direct Known Subclasses:

DFSonDAGBottomTop, DFSonDAGs, DFSWorkStealing, DynamicParIterator, StaticParIterator

public abstract class ParIteratorAbstract<E>
extends java.lang.Object
implements ParIterator<E>

Author: xiaoxing Date: 31/05/13

Nested Class Summary

Nested classes/interfaces inherited from interface pu.pi.ParIterator

ParIterator.Schedule

Field Summary

Fields

Modifier and Type	Field and Description
protected int	chunkSize
protected java.util.Collection<E>	collection
protected java.util.List<E>	data
protected java.util.concurrent.ConcurrentLinkedQueue<ParIteratorException<E>>	exceptions
protected Flags	flags
protected boolean	ignoreBarrier
protected java.util.concurrent.CountDownLatch	latch
protected int	numOfThreads
protected java.util.concurrent.ConcurrentLinkedQueue<java.util.Iterator<E>>	reclaimedElements
protected ThreadID	threadID

Fields inherited from interface pu.pi.ParIterator

DEFAULT_CHUNKSIZE

Constructor Summary

Constructors

Constructor and Description
ParIteratorAbstract(java.util.Collection<E> collection, int chunkSize, int numOfThreads, boolean ignoreBarrier)
ParIteratorAbstract(int numOfThreads, boolean ignoreBarrier)

Method Summary

Modifier and Type	Method and Description
protected boolean	allOtherThreadsHaveLocalBreaked(int tid)
ParIteratorException<E>[]	getAllExceptions() Returns all the exceptions that have (so far) occurred during traversal of the Parallel Iterator.
int	getID() For test.
void	globalBreak() Causes all threads to stop processing elements at the next iteration boundary.
void	register(java.lang.Exception e) When a thread encounters an exception during traversal of a Parallel Iterator, the exception is registered using this method.
void	register(java.lang.Exception e, E currentElements)
void	remove() Removes from the underlying collection the last element returned by the Parallel Iterator to the current thread.
void	reset() Reset ParIterator for reuse.

Methods inherited from class java.lang.Object

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

Methods inherited from interface pu.pi.ParIterator

hasNext, localBreak, next

Methods inherited from interface java.util.Iterator

forEachRemaining

Field Detail

chunkSize

protected int chunkSize

numOfThreads

protected final int numOfThreads

latch

protected java.util.concurrent.CountDownLatch latch

ignoreBarrier

protected boolean ignoreBarrier

threadID

protected final ThreadID threadID

data

protected java.util.List<E> data

collection

protected java.util.Collection<E> collection

reclaimedElements

protected final java.util.concurrent.ConcurrentLinkedQueue<java.util.Iterator<E>> reclaimedElements

exceptions

protected java.util.concurrent.ConcurrentLinkedQueue<ParIteratorException<E>> exceptions

flags

protected final Flags flags

Constructor Detail

ParIteratorAbstract

public ParIteratorAbstract(java.util.Collection<E> collection,
                           int chunkSize,
                           int numOfThreads,
                           boolean ignoreBarrier)

ParIteratorAbstract

public ParIteratorAbstract(int numOfThreads,
                           boolean ignoreBarrier)

Method Detail

remove

public void remove()

Description copied from interface: ParIterator

Removes from the underlying collection the last element returned by the Parallel Iterator to the current thread.

Specified by:

remove in interface java.util.Iterator<E>

Specified by:

remove in interface ParIterator<E>

reset

public void reset()

Description copied from interface: ParIterator

Reset ParIterator for reuse.

Specified by:

reset in interface ParIterator<E>

globalBreak

public void globalBreak()

Description copied from interface: ParIterator

Causes all threads to stop processing elements at the next iteration boundary. Therefore, even if there were any unprocessed elements, they will not be processed. In such a case, false is returned to every thread at the next call to hasNext(). Therefore, all the threads safely stop iterating when they call hasNext() (includes an implicit barrier to ensure all threads stop at the same time).

Specified by:

globalBreak in interface ParIterator<E>

See Also:

ParIterator.localBreak()

allOtherThreadsHaveLocalBreaked

protected boolean allOtherThreadsHaveLocalBreaked(int tid)

register

public void register(java.lang.Exception e)

Description copied from interface: ParIterator

When a thread encounters an exception during traversal of a Parallel Iterator, the exception is registered using this method. Therefore, calling this method records the following information (wrapped inside a ParIteratorException):

• e - The exception that occurred
• The current thread (who encountered the exception)
• The current element that the thread was processing (the hasNext() method serves as the iteration boundary to determine the current element).

Specified by:

register in interface ParIterator<E>

Parameters:

e - The exception to register

See Also:

ParIterator.getAllExceptions()

register

public void register(java.lang.Exception e,
                     E currentElements)

getAllExceptions

public ParIteratorException<E>[] getAllExceptions()

Description copied from interface: ParIterator

Returns all the exceptions that have (so far) occurred during traversal of the Parallel Iterator. All exceptions must be caught and then registered by the thread that caught the exception.

Specified by:

getAllExceptions in interface ParIterator<E>

Returns:

All the exceptions (each is wrapped inside a ParIteratorException), or an empty array if none were registered.

See Also:

ParIterator.register(Exception)

getID

public int getID()

Description copied from interface: ParIterator

For test.

Specified by:

getID in interface ParIterator<E>

Returns:

thread ID.