javax.realtime

Interface Schedulable

All Superinterfaces:

Releasable<Timable,TimeDispatcher>, Runnable, Subsumable<Schedulable>, Timable

All Known Subinterfaces:

BoundSchedulable

All Known Implementing Classes:

AsyncBaseEventHandler, AsyncEventHandler, AsyncLongEventHandler, AsyncObjectEventHandler, BoundAsyncEventHandler, BoundAsyncLongEventHandler, BoundAsyncObjectEventHandler, NoHeapRealtimeThread, RealtimeThread

public interface Schedulable
extends Runnable, Timable, Subsumable<Schedulable>

Jamaica Real-Time Specification for Java class Schedulable.

Schedulable objects are executable entities that are scheduled by the scheduler, that may get assigned execution time, that may be released by events and that may participate in feasibility analysis.

Supported schedulable objects are RealtimeThread and AsyncBaseEventHandler.

Method Summary

Modifier and Type	Method and Description
boolean	addToFeasibility() addToFeasibility notifies the scheduler associated with this that this schedulable object's scheduling, release, memory, and processing group parameters take part in the feasibility analysis.
ConfigurationParameters	getConfigurationParameters() Obtain the configuration parameters.
MemoryParameters	getMemoryParameters() getMemoryParameters returns a reference to the MemoryParameters of this Schedulable.
ProcessingGroupParameters	getProcessingGroupParameters() getProcessingGroupParameters returns the current ProcessingGroupParameters of this Schedulable.
ReleaseParameters<?>	getReleaseParameters() getReleaseParameters returns the current ReleaseParameters of this Schedulable.
Scheduler	getScheduler() getScheduler returns the current scheduler of this Schedulable.
SchedulingParameters	getSchedulingParameters() getSchedulingParameters returns the SchedulingParameters of this Schedulable.
boolean	isDaemon() Tests if this event handler is a daemon handler.
boolean	mayUseHeap() Determines whether or not this schedulable may use the heap.
boolean	removeFromFeasibility() removeFromFeasibility informs the scheduler associated with this AsyncBaseEventHandler that this AsyncBaseEventHandler should no longer be taken into account in the feasibility analysis.
void	setDaemon(boolean on) Marks this schedulable as either a daemon or a user task.
Schedulable	setMemoryParameters(MemoryParameters memory) setMemoryParameters replaces the memory parameters for this Schedulable with the parameters provided.
void	setProcessingGroupParameters(ProcessingGroupParameters groupParameters) setProcessingGroupParameters sets the processing group parameters of this Scheduling.
Schedulable	setReleaseParameters(ReleaseParameters<?> release) setReleaseParameters replaces the release parameters for this Schedulable with the parameters provided.
Schedulable	setScheduler(Scheduler scheduler) setScheduler sets the scheduler for this Schedulable.
Schedulable	setScheduler(Scheduler scheduler, SchedulingParameters scheduling, ReleaseParameters<?> release, MemoryParameters memoryParameters) setScheduler set the scheduler and scheduling, release, memory and processing group parameters for this Schedulable.
Schedulable	setSchedulingParameters(SchedulingParameters scheduling) setSchedulingParameters sets the scheduling parameters for this Schedulable.
boolean	subsumes(Schedulable other) Determine whether or not this instance of Schedulable is more eligible than other.

Methods inherited from interface java.lang.Runnable

run

Methods inherited from interface javax.realtime.Timable

getDispatcher

Method Detail

subsumes

boolean subsumes(Schedulable other)

Determine whether or not this instance of Schedulable is more eligible than other. On multicore systems, this only gives a partial ordering over all schedulables. Schedulables with disjoint processor affinity do not subsume one another.

Specified by:

subsumes in interface Subsumable<Schedulable>

Parameters:

other - The object to be compared with.

Returns:

true when and only when this instance of Schedulable is more eligible than other.

Since:

RTSJ 2.0

setDaemon

void setDaemon(boolean on)

Marks this schedulable as either a daemon or a user task. A realtime virtual machine exits when the only tasks running are all daemons. This method must be called before the task is attached to any event or started. Once attached or started, it cannot be changed.

Throws:

IllegalThreadStateException - when this schedulable is active.

StaticSecurityException - when the current schedulable cannot modify this event handler.

Parameters:

on - When true, marks this event handler as a daemon handler.

Since:

RTSJ 2.0

isDaemon

boolean isDaemon()

Tests if this event handler is a daemon handler.

Returns:

true when this event handler is a daemon handler; false otherwise.

Since:

RTSJ 2.0

mayUseHeap

boolean mayUseHeap()

Determines whether or not this schedulable may use the heap.

Returns:

true only when this Schedulable may allocate on the heap and may enter the Heap.

Since:

RTSJ 2.0

getConfigurationParameters

ConfigurationParameters getConfigurationParameters()

Obtain the configuration parameters.

Returns:

the current configuration parameters.

Since:

RTSJ 2.0

getMemoryParameters

MemoryParameters getMemoryParameters()

getMemoryParameters returns a reference to the MemoryParameters of this Schedulable.

Returns:

the MemoryParameters of this Schedulable.

getReleaseParameters

ReleaseParameters<?> getReleaseParameters()

getReleaseParameters returns the current ReleaseParameters of this Schedulable.

Returns:

the ReleaseParameters.

getScheduler

Scheduler getScheduler()

getScheduler returns the current scheduler of this Schedulable.

Returns:

the scheduler.

getSchedulingParameters

SchedulingParameters getSchedulingParameters()

getSchedulingParameters returns the SchedulingParameters of this Schedulable.

Returns:

the SchedulingParameters.

getProcessingGroupParameters

ProcessingGroupParameters getProcessingGroupParameters()

getProcessingGroupParameters returns the current ProcessingGroupParameters of this Schedulable.

Returns:

the ProcessingGroupParameters

setMemoryParameters

Schedulable setMemoryParameters(MemoryParameters memory)

setMemoryParameters replaces the memory parameters for this Schedulable with the parameters provided.

This change may change the feasibility of the current feasible set of this Schedulable's scheduler.

In JamaicaVM, this change becomes effective immediately.

Throws:

IllegalArgumentException - if the memory parameter value is not compatible with the scheduler associated to this Schedulable.

IllegalAssignmentError - if memory and this reside in memory areas whose objects cannot refer to one another (in both directions).

Parameters:

memory - the new memory parameters. If null, the default value for the associated scheduler will be used.

Since:

RTSJ 2.0 returns itself

setReleaseParameters

Schedulable setReleaseParameters(ReleaseParameters<?> release)

setReleaseParameters replaces the release parameters for this Schedulable with the parameters provided.

This change may change the feasibility of the current feasible set of this Schedulable's scheduler.

In JamaicaVM, this change of periodic parameters becomes effective after the execution of the next period, i.e., on the next call to waitForNextPeriod or waitForNextPeriodInterruptible.

Throws:

IllegalArgumentException - if the release parameter value is not compatible with the scheduler associated to this Schedulable.

IllegalAssignmentError - if release and this reside in memory areas whose objects cannot refer to one another (in both directions).

IllegalThreadStateException - If the old release parameters are periodic, the new release parameters are not periodic, and the schedulable object is currently blocked in RealtimeThread.waitForNextPeriod or RealtimeThread.waitForNextPeriodInterruptible.

Parameters:

release - the new release parameters. If null, the default value for the associated scheduler will be used.

Since:

RTSJ 2.0 returns itself

setScheduler

Schedulable setScheduler(Scheduler scheduler)

setScheduler sets the scheduler for this Schedulable. If this has been admitted to the feasible set, it remains in the feasible set.

This change may change the feasibility of the current feasible set of this Schedulable's scheduler.

Throws:

IllegalArgumentException - iff the scheduler is null or the current parameters of this are not compatible with the new scheduler.

IllegalAssignmentError - if scheduler and this reside in memory areas whose objects cannot refer to one another (in both directions).

SecurityException - if setting of the scheduler is not allowed by the current RealtimeSystem setting.

Parameters:

scheduler - the new scheduler to be used. Must not be null.

Since:

RTSJ 2.0 returns itself

setScheduler

Schedulable setScheduler(Scheduler scheduler,
                         SchedulingParameters scheduling,
                         ReleaseParameters<?> release,
                         MemoryParameters memoryParameters)

setScheduler set the scheduler and scheduling, release, memory and processing group parameters for this Schedulable.

The change of the scheduler and scheduling and memory parameters will be immediate for the default scheduler. release and processing group parameters will take effect on the next release.

This change may change the feasibility of the current feasible set of this Schedulable's scheduler.

Throws:

IllegalArgumentException - when scheduler is null or the scheduling, release, memory or processing group parameters are not compatible with the scheduler.

IllegalAssignmentError - if scheduler, scheduling, release, memory, or group reside in memory areas whose objects cannot be referred to by this or this object resides in a memory area that cannot be referenced by scheduling, release or memory.

IllegalThreadStateException - If the old release parameters are periodic, the new release parameters are not periodic, and the schedulable object is currently blocked in waitForNextPeriod or waitForNextPeriodInterruptible.

SecurityException - if setting of the scheduler is not allowed by the current RealtimeSystem setting.

Parameters:

scheduler - The scheduler to be used for this Schedulable. Must not be null.

scheduling - SchedulingParameters to be associated with the RealtimeThread. If null, the default value of the scheduler will be used.

release - the new release parameters. If null, the default value for the associated scheduler will be used.

memoryParameters - the new memory parameters. If null, the default value for the associated scheduler will be used.

setSchedulingParameters

Schedulable setSchedulingParameters(SchedulingParameters scheduling)

setSchedulingParameters sets the scheduling parameters for this Schedulable.

In JamaicaVM, this change of scheduling parameters becomes effective immediately for the default PriorityScheduler.

Throws:

StaticIllegalArgumentException - iff scheduling is not compatible with the scheduler.

IllegalAssignmentError - if scheduling and this reside in memory areas whose objects cannot refer to one another (in both directions).

Parameters:

scheduling - the new scheduling parameters.

setProcessingGroupParameters

void setProcessingGroupParameters(ProcessingGroupParameters groupParameters)

setProcessingGroupParameters sets the processing group parameters of this Scheduling.

In JamaicaVM, this change becomes effective immediately.

This change may change the feasibility of the current feasible set of this Schedulable's scheduler.

Throws:

IllegalArgumentException - if the group argument is not compatible with the scheduler of this RealtimeThread.

Parameters:

groupParameters - the new processing group parameters to be applied for the next release of this. If null, use the default value for the scheduler.

addToFeasibility

boolean addToFeasibility()

addToFeasibility notifies the scheduler associated with this that this schedulable object's scheduling, release, memory, and processing group parameters take part in the feasibility analysis.

In case this schedulable object is already part of the feasibility analysis, do nothing.

Returns:

true iff the resulting system is feasible.

removeFromFeasibility

boolean removeFromFeasibility()

removeFromFeasibility informs the scheduler associated with this AsyncBaseEventHandler that this AsyncBaseEventHandler should no longer be taken into account in the feasibility analysis.

Returns:

true iff this could be removed successfully, false iff this was not part of the feasible set of the assigned scheduler.