javax.realtime.util
Class PooledExecutor

java.lang.Object
  javax.realtime.util.PooledExecutor

All Implemented Interfaces:

Executor, Runnable, Schedulable

public class PooledExecutor

extends Object

implements Executor

This class represent an abstraction for an Executor that is actually a pool of Executors. The QoS parameters used to create this class are used as default parameters for the pool's Executors.
NOTE: The basic idea behind executors pool, is that the each individual executor changes its QoS in order to adjust to the schedulable entity for which it is running. No schedulability check is done while changing the QoS, because the change should keep the system feasible as far as the entity that is using the executor was considered in the feasibility analysis.

Author:

Angelo Corsaro

Constructor Summary

PooledExecutor(int executorNum, SchedulingParameters schedulingParam, ReleaseParameters releaseParam, MemoryParameters memoryParam, MemoryArea memoryArea, ProcessingGroupParameters groupParam, boolean noHeap)
Creates a new PooledExecutor instance with the specified parameters.

Method Summary

boolean	addIfFeasible() Add to the feasibility of the already set scheduler if the resulting feasibility set is schedulable.
boolean	addToFeasibility() Inform the scheduler and cooperating facilities that the resource demands (as expressed in the associated instances of SchedulingParameters, ReleaseParameters, MemoryParameters, and ProcessingGroupParameters) of this instance of Schedulable will be considered in the feasibility analysis of the associated Scheduler until further notice.
void	execute(Runnable task) Executes the given logic.
int	executionEligibility() NOTE: This method is not part of the RTSJ Specification.
MemoryParameters	getMemoryParameters() Get the MemoryParameters of this schedulable object.
ProcessingGroupParameters	getProcessingGroupParameters() Get the ProcessingGroupParameters of this schedulable object.
ReleaseParameters	getReleaseParameters() Get the ReleaseParameters of this schedulable object.
Scheduler	getScheduler() Get the Scheduler for this schedulable object.
SchedulingParameters	getSchedulingParameters() Get the SchedulingParameters for this schedulable object.
boolean	removeFromFeasibility() Inform the scheduler and cooperating facilities that the resource demands, as expressed in the associated instances of SchedulingParameters, ReleaseParameters, MemoryParameters, and ProcessingGroupParameters, of this instance of Schedulable should no longer be considered in the feasibility analysis of the associated Scheduler.
void	run()
void	setMemoryParameters(MemoryParameters memoryParam) Set the MemoryParameters for this schedulable object.
boolean	setMemoryParametersIfFeasible(MemoryParameters memoryParam) Returns true if, after considering the value of the parameter, the task set would still be feasible.
void	setProcessingGroupParameters(ProcessingGroupParameters groupParam) Set the ProcessingGroupParameters for this schedulable object.
boolean	setProcessingGroupParametersIfFeasible(ProcessingGroupParameters groupParam) Set the ProcessingGroupParameters of this schedulable object only if the resulting task set is feasible.
void	setReleaseParameters(ReleaseParameters releaseParam) Set the ReleaseParametersfor this schedulable object.
boolean	setReleaseParametersIfFeasible(ReleaseParameters releaseParam) Returns true if, after considering the value of the parameter, the task set would still be feasible.
void	setScheduler(Scheduler scheduler) Set the Scheduler for this schedulable object.
void	setScheduler(Scheduler scheduler, SchedulingParameters schedulingParam, ReleaseParameters releaseParam, MemoryParameters memoryParam, ProcessingGroupParameters groupParam) Set the Scheduler for this schedulable object.
void	setSchedulingParameters(SchedulingParameters schedulingParam) Set the SchedulingParameters for this schedulable object only if the resulting task set is feasible.
boolean	setSchedulingParametersIfFeasible(SchedulingParameters schedulingParam) Set the SchedulingParameters for this schedulable object.
void	shutdown() Releases all the resources assoiated with the executor.

Methods inherited from class java.lang.Object

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

Constructor Detail

PooledExecutor

public PooledExecutor(int executorNum,
                      SchedulingParameters schedulingParam,
                      ReleaseParameters releaseParam,
                      MemoryParameters memoryParam,
                      MemoryArea memoryArea,
                      ProcessingGroupParameters groupParam,
                      boolean noHeap)
               throws IllegalArgumentException

Creates a new PooledExecutor instance with the specified parameters.

Parameters:

schedulingParam - a SchedulingParameters value which will be associated with the constructed instance of this. If null this will be assigned the reference to the SchedulingParameters of the current thread.

releaseParam - a ReleaseParameters value which will be associated with the constructed instance of this. If null this will have no ReleaseParameters.

memoryParam - a MemoryParameters value which will be associated with the constructed instance of this. If null this will have no MemoryParameters.

memoryArea - The MemoryArea for this PooledExecutor. If null, inherit the current memory area at the time of construction. The initial memory area must be a reference to a ScopedMemory or ImmortalMemory object if noheap is true.

groupParam - A ProcessingGroupParameters object to which this will be associated. If null this will not be associated with any processing group.

noHeap - A flag meaning, when true, that this will have characteristics identical to a NoHeapRealtimeThread. A false value means this will have characteristics identical to a RealtimeThread. If true and the current thread is not a NoHeapRealtimeThread or a RealtimeThread executing within a ScopedMemory or ImmortalMemory scope then an IllegalArgumentException is thrown.

Method Detail

execute

public void execute(Runnable task)
             throws ShutdownExecutorException

Description copied from interface: Executor

Executes the given logic. If the logic is executed on a newly created thread, or of a thread is borrowed from a pool is implementation dependent.

Specified by:

execute in interface Executor

Parameters:

task - a Runnable value

Throws:

ShutdownExecutorException - if the Executor has already been shut down.

shutdown

public void shutdown()

Description copied from interface: Executor

Releases all the resources assoiated with the executor. No subsequent invocation of the execute() method should be performed after the executor has been shutdown.

Specified by:

shutdown in interface Executor

addIfFeasible

public boolean addIfFeasible()

Add to the feasibility of the already set scheduler if the resulting feasibility set is schedulable. If successful return true, if not return false. If there is not an assigned scheduler it will return false.

Specified by:

addIfFeasible in interface Schedulable

Returns:

If successful return true, if not return false. If there is not an assigned scheduler it will return false.

addToFeasibility

public boolean addToFeasibility()

Inform the scheduler and cooperating facilities that the resource demands (as expressed in the associated instances of SchedulingParameters, ReleaseParameters, MemoryParameters, and ProcessingGroupParameters) of this instance of Schedulable will be considered in the feasibility analysis of the associated Scheduler until further notice. Whether the resulting system is feasible or not, the addition is completed.

Specified by:

addToFeasibility in interface Schedulable

Returns:

true If the resulting system is feasible.

getMemoryParameters

public MemoryParameters getMemoryParameters()

Get the MemoryParameters of this schedulable object.

Specified by:

getMemoryParameters in interface Schedulable

Returns:

a MemoryParameters value.

setMemoryParameters

public void setMemoryParameters(MemoryParameters memoryParam)

Set the MemoryParameters for this schedulable object.

Specified by:

setMemoryParameters in interface Schedulable

Parameters:

memoryParam - the MemoryParameters for this schedulable object.

setMemoryParametersIfFeasible

public boolean setMemoryParametersIfFeasible(MemoryParameters memoryParam)

Returns true if, after considering the value of the parameter, the task set would still be feasible. In this case the values of the parameters are changed. Returns false if, after considering the value of the parameter, the task set would not be feasible. In this case the values of the parameters are not changed.

Specified by:

setMemoryParametersIfFeasible in interface Schedulable

Parameters:

memoryParam - the MemoryParameters for this schedulable object.

Returns:

true if the requested change keeps the system feasible.

getProcessingGroupParameters

public ProcessingGroupParameters getProcessingGroupParameters()

Get the ProcessingGroupParameters of this schedulable object.

Specified by:

getProcessingGroupParameters in interface Schedulable

Returns:

a ProcessingGroupParameters value

setProcessingGroupParameters

public void setProcessingGroupParameters(ProcessingGroupParameters groupParam)

Set the ProcessingGroupParameters for this schedulable object.

Specified by:

setProcessingGroupParameters in interface Schedulable

Parameters:

groupParam - a ProcessingGroupParameters value

setProcessingGroupParametersIfFeasible

public boolean setProcessingGroupParametersIfFeasible(ProcessingGroupParameters groupParam)

Set the ProcessingGroupParameters of this schedulable object only if the resulting task set is feasible.

Specified by:

setProcessingGroupParametersIfFeasible in interface Schedulable

Parameters:

groupParam - a ProcessingGroupParameters value

Returns:

Returns true if, after considering the values of the parameters, the task set would still be feasible. In this case the values of the parameters are changed. Returns false if, after considering the values of the parameters, the task set would not be feasible. In this case the values of the parameters are not changed.

getReleaseParameters

public ReleaseParameters getReleaseParameters()

Get the ReleaseParameters of this schedulable object.

Specified by:

getReleaseParameters in interface Schedulable

Returns:

a ReleaseParameters value

setReleaseParameters

public void setReleaseParameters(ReleaseParameters releaseParam)

Set the ReleaseParametersfor this schedulable object.

Specified by:

setReleaseParameters in interface Schedulable

Parameters:

releaseParam - a ReleaseParameters value

setReleaseParametersIfFeasible

public boolean setReleaseParametersIfFeasible(ReleaseParameters releaseParam)

Returns true if, after considering the value of the parameter, the task set would still be feasible. In this case the values of the parameters are changed. Returns false if, after considering the value of the parameter, the task set would not be feasible. In this case the values of the parameters are not changed. the resulting task set is feasible.

Specified by:

setReleaseParametersIfFeasible in interface Schedulable

Parameters:

releaseParam - a ReleaseParameters value

getScheduler

public Scheduler getScheduler()

Get the Scheduler for this schedulable object.

Specified by:

getScheduler in interface Schedulable

Returns:

a Scheduler value

setScheduler

public void setScheduler(Scheduler scheduler)
                  throws IllegalThreadStateException

Set the Scheduler for this schedulable object.

Specified by:

setScheduler in interface Schedulable

Parameters:

scheduler - the scheduler.

Throws:

IllegalThreadStateException

setScheduler

public void setScheduler(Scheduler scheduler,
                         SchedulingParameters schedulingParam,
                         ReleaseParameters releaseParam,
                         MemoryParameters memoryParam,
                         ProcessingGroupParameters groupParam)
                  throws IllegalThreadStateException

Set the Scheduler for this schedulable object.

Specified by:

setScheduler in interface Schedulable

Parameters:

scheduler - a Scheduler value

schedulingParam - a SchedulingParameters value

releaseParam - a ReleaseParameters value

memoryParam - a MemoryParameters value

groupParam - a ProcessingGroupParameters value

Throws:

IllegalThreadStateException - if an error occurs

getSchedulingParameters

public SchedulingParameters getSchedulingParameters()

Get the SchedulingParameters for this schedulable object.

Specified by:

getSchedulingParameters in interface Schedulable

Returns:

a SchedulingParameters value

setSchedulingParameters

public void setSchedulingParameters(SchedulingParameters schedulingParam)

Set the SchedulingParameters for this schedulable object only if the resulting task set is feasible.

Specified by:

setSchedulingParameters in interface Schedulable

Parameters:

schedulingParam - a SchedulingParameters value

setSchedulingParametersIfFeasible

public boolean setSchedulingParametersIfFeasible(SchedulingParameters schedulingParam)

Set the SchedulingParameters for this schedulable object.

Specified by:

setSchedulingParametersIfFeasible in interface Schedulable

Parameters:

schedulingParam - a SchedulingParameters value

Returns:

true if the change was feasible, false otherwise.

removeFromFeasibility

public boolean removeFromFeasibility()

Inform the scheduler and cooperating facilities that the resource demands, as expressed in the associated instances of SchedulingParameters, ReleaseParameters, MemoryParameters, and ProcessingGroupParameters, of this instance of Schedulable should no longer be considered in the feasibility analysis of the associated Scheduler. Whether the resulting system is feasible or not, the subtrac-tion is completed.

Specified by:

removeFromFeasibility in interface Schedulable

Returns:

true If the resulting system is feasible.

executionEligibility

public int executionEligibility()

Description copied from interface: Schedulable

NOTE: This method is not part of the RTSJ Specification. It is used internally by this RTSJ implementation.

Specified by:

executionEligibility in interface Schedulable

Returns:

an int value used internally to represent a total ordering of the schedulable entities.

run

public void run()

Specified by:

run in interface Runnable