org.eclipse.rdf4j.federated.evaluation.concurrent

Class ControlledWorkerScheduler<T>

java.lang.Object

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

All Implemented Interfaces:

Scheduler<T>

public class ControlledWorkerScheduler<T>
extends Object
implements Scheduler<T>

ControlledWorkerScheduler is a task scheduler that uses a FIFO queue for managing its process. Each instance has a pool with a fixed number of worker threads. Once notified a worker picks the next task from the queue and executes it. The results is then returned to the controlling instance retrieved from the task.

Author:

Andreas Schwarte

See Also:

ControlledWorkerUnion, ControlledWorkerJoin, ControlledWorkerBoundJoin

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	ControlledWorkerScheduler.ControlStatus Structure to maintain the status for a given control instance.

Constructor Summary

Constructors

Constructor and Description
ControlledWorkerScheduler() Construct a new instance with 20 workers.
ControlledWorkerScheduler(int nWorkers, String name) Construct a new instance with the specified number of workers and the given name.

Method Summary

Modifier and Type	Method and Description
void	abort() Abort the execution of running and queued tasks.
void	done() Inform the scheduler that a certain task is done.
int	getNumberOfTasks()
int	getTotalNumberOfWorkers()
void	handleResult(CloseableIteration<T,QueryEvaluationException> res) Callback to handle the result.
void	informFinish() Inform the scheduler that no more tasks will be scheduled.
void	informFinish(ParallelExecutor<T> control) Inform this scheduler that the specified control instance will no longer submit tasks.
boolean	isRunning() Determine if the scheduler has unfinished tasks.
boolean	isRunning(ParallelExecutor<T> control) Determine if there are still task running or queued for the specified control.
void	schedule(ParallelTask<T> task) Schedule the specified parallel task.
void	scheduleAll(List<ParallelTask<T>> tasks, ParallelExecutor<T> control) Schedule the given tasks and inform about finish using the same lock, i.e.
void	shutdown()
void	toss(Exception e) Toss an exception to the scheduler.

Methods inherited from class java.lang.Object

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

Constructor Detail

ControlledWorkerScheduler

public ControlledWorkerScheduler()

Construct a new instance with 20 workers.

ControlledWorkerScheduler

public ControlledWorkerScheduler(int nWorkers,
                                 String name)

Construct a new instance with the specified number of workers and the given name.

Parameters:

nWorkers -

name -

Method Detail

schedule

public void schedule(ParallelTask<T> task)

Schedule the specified parallel task.

Specified by:

schedule in interface Scheduler<T>

Parameters:

task - the task to schedule

scheduleAll

public void scheduleAll(List<ParallelTask<T>> tasks,
                        ParallelExecutor<T> control)

Schedule the given tasks and inform about finish using the same lock, i.e. all tasks are scheduled one after the other.

Parameters:

tasks -

control -

getTotalNumberOfWorkers

public int getTotalNumberOfWorkers()

getNumberOfTasks

public int getNumberOfTasks()

abort

public void abort()

Description copied from interface: Scheduler

Abort the execution of running and queued tasks.

Specified by:

abort in interface Scheduler<T>

done

public void done()

Description copied from interface: Scheduler

Inform the scheduler that a certain task is done.

Specified by:

done in interface Scheduler<T>

handleResult

public void handleResult(CloseableIteration<T,QueryEvaluationException> res)

Description copied from interface: Scheduler

Callback to handle the result.

Specified by:

handleResult in interface Scheduler<T>

informFinish

public void informFinish()

Description copied from interface: Scheduler

Inform the scheduler that no more tasks will be scheduled.

Specified by:

informFinish in interface Scheduler<T>

informFinish

public void informFinish(ParallelExecutor<T> control)

Inform this scheduler that the specified control instance will no longer submit tasks.

Parameters:

control -

isRunning

public boolean isRunning()

Description copied from interface: Scheduler

Determine if the scheduler has unfinished tasks.

Specified by:

isRunning in interface Scheduler<T>

Returns:

whether the scheduler is running

isRunning

public boolean isRunning(ParallelExecutor<T> control)

Determine if there are still task running or queued for the specified control.

Parameters:

control -

Returns:

true, if there are unfinished tasks, false otherwise

toss

public void toss(Exception e)

Description copied from interface: Scheduler

Toss an exception to the scheduler.

Specified by:

toss in interface Scheduler<T>

shutdown

public void shutdown()

Specified by:

shutdown in interface Scheduler<T>