Package org.eclipse.rdf4j.federated.evaluation.union

Class ControlledWorkerUnion<T>

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>

org.eclipse.rdf4j.common.iteration.LookAheadIteration<T,QueryEvaluationException>

org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelExecutorBase<T>

org.eclipse.rdf4j.federated.evaluation.union.UnionExecutorBase<T>

org.eclipse.rdf4j.federated.evaluation.union.WorkerUnionBase<T>

org.eclipse.rdf4j.federated.evaluation.union.ControlledWorkerUnion<T>

All Implemented Interfaces:

AutoCloseable, Runnable, CloseableIteration<T,QueryEvaluationException>, Iteration<T,QueryEvaluationException>, ParallelExecutor<T>

public class ControlledWorkerUnion<T>
extends WorkerUnionBase<T>

Execution of union tasks with ControlledWorkerScheduler. Tasks can be added using the provided functions. Note that the union operation is to be executed with the ParallelExecutorBase.run() method (also threaded execution is possible). Results are then contained in this iteration.

Author:

Andreas Schwarte

Field Summary

Fields

Modifier and Type	Field	Description
static int	awakeCount
protected final Phaser	phaser
protected final ControlledWorkerScheduler<T>	scheduler
static int	waitingCount

Fields inherited from class org.eclipse.rdf4j.federated.evaluation.union.WorkerUnionBase

tasks

Fields inherited from class org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelExecutorBase

evaluationThread, executorId, finished, log, NEXT_EXECUTOR_ID, queryInfo, rightIter, rightQueue, strategy

Constructor Summary

Constructors

Constructor	Description
ControlledWorkerUnion(ControlledWorkerScheduler<T> scheduler, QueryInfo queryInfo)

Method Summary

Modifier and Type	Method	Description
void	done()	Inform the controlling instance that some job is done from a different thread.
void	handleClose()	Called by AbstractCloseableIteration.close() when it is called for the first time.
void	toss(Exception e)	Toss some exception to the controlling instance
protected void	union()	Note: this method must block until the union is executed completely.

Methods inherited from class org.eclipse.rdf4j.federated.evaluation.union.WorkerUnionBase

addTask

Methods inherited from class org.eclipse.rdf4j.federated.evaluation.union.UnionExecutorBase

getExecutorType, performExecution

Methods inherited from class org.eclipse.rdf4j.federated.evaluation.concurrent.ParallelExecutorBase

addResult, checkTimeout, getDisplayId, getId, getNextElement, getQueryInfo, isFinished, run, toString

Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration

hasNext, next, remove

Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

close, isClosed

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.common.iteration.CloseableIteration

stream

Field Details

waitingCount

public static int waitingCount

awakeCount

public static int awakeCount

scheduler

protected final ControlledWorkerScheduler<T> scheduler

phaser

protected final Phaser phaser

Constructor Details

ControlledWorkerUnion

public ControlledWorkerUnion(ControlledWorkerScheduler<T> scheduler,
 QueryInfo queryInfo)

Method Details

union

protected void union()
              throws Exception

Description copied from class: UnionExecutorBase

Note: this method must block until the union is executed completely. Otherwise the result queue is marked as committed while this isn't the case. The blocking behavior in general is no problem: If you need concurrent access to the result (i.e. pipelining) just run the union in a separate thread. Access to the result iteration is synchronized.

Specified by:

union in class UnionExecutorBase<T>

Throws:

Exception

done

public void done()

Description copied from interface: ParallelExecutor

Inform the controlling instance that some job is done from a different thread. In most cases this is a no-op.

Specified by:

done in interface ParallelExecutor<T>

Overrides:

done in class ParallelExecutorBase<T>

toss

public void toss(Exception e)

Description copied from interface: ParallelExecutor

Toss some exception to the controlling instance

Specified by:

toss in interface ParallelExecutor<T>

Overrides:

toss in class ParallelExecutorBase<T>

handleClose

public void handleClose()
                 throws QueryEvaluationException

Description copied from class: AbstractCloseableIteration

Called by AbstractCloseableIteration.close() when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.

Overrides:

handleClose in class WorkerUnionBase<T>

Throws:

QueryEvaluationException