javax.realtime

Interface Schedulable

All Superinterfaces:

java.lang.Runnable, Subsumable<Schedulable>

All Known Subinterfaces:

BoundSchedulable

All Known Implementing Classes:

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

public interface Schedulable
extends java.lang.Runnable, Subsumable<Schedulable>

An interface for all types of task defined in this specification. All implementations of Schedulable can be scheduled by any Scheduler defined here. A scheduler uses the information available through this interface to create a suitable context in which to execute the code encapsulated by this object.

Method Summary

Modifier and Type	Method and Description
default boolean	addToFeasibility() Deprecated. as of RTSJ 2.0 The framework for feasibility analysis is inadequate.
ConfigurationParameters	getConfigurationParameters() Gets a reference to the ConfigurationParameters object for this schedulable.
MemoryParameters	getMemoryParameters() Gets a reference to the MemoryParameters object for this schedulable.
default ProcessingGroupParameters	getProcessingGroupParameters() Deprecated. since RTSJ 2.0
ReleaseParameters<?>	getReleaseParameters() Gets a reference to the ReleaseParameters object for this schedulable.
Scheduler	getScheduler() Gets a reference to the Scheduler object for this schedulable.
SchedulingParameters	getSchedulingParameters() Gets a reference to the SchedulingParameters object for 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.
default boolean	removeFromFeasibility() Deprecated. as of RTSJ 2.0 The framework for feasibility analysis is inadequate
void	setDaemon(boolean on) Marks this schedulable as either a daemon or a user task.
Schedulable	setMemoryParameters(MemoryParameters memory) Sets the memory parameters associated with this instance of Schedulable.
default void	setProcessingGroupParameters(ProcessingGroupParameters group) Deprecated. since RTSJ 2.0; see ProcessingConstraint.
Schedulable	setReleaseParameters(ReleaseParameters<?> release) Sets the release parameters associated with this instance of Schedulable.
Schedulable	setScheduler(Scheduler scheduler) Sets the reference to the Scheduler object.
Schedulable	setScheduler(Scheduler scheduler, SchedulingParameters scheduling, ReleaseParameters<?> release, MemoryParameters memoryParameters) Sets the scheduler and associated parameter objects.
Schedulable	setSchedulingParameters(SchedulingParameters scheduling) Sets the scheduling parameters associated with this instance of 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

Method Detail

getMemoryParameters

MemoryParameters getMemoryParameters()

Gets a reference to the MemoryParameters object for this schedulable.

Returns:

a reference to the current MemoryParameters object.

setMemoryParameters

Schedulable setMemoryParameters(MemoryParameters memory)

Sets the memory parameters associated with this instance of Schedulable.

This change becomes effective at the next allocation; on multiprocessor systems, there may be some delay due to synchronization between processors.

Parameters:

memory - A MemoryParameters object which will become the memory parameters associated with this after the method call. When null, the default value is governed by the associated scheduler; a new object is created when the default value is not null. (See PriorityScheduler.)

Returns:

this

Throws:

StaticIllegalArgumentException - when memory is not compatible with the schedulable's scheduler. Also when this schedulable may not use the heap and memory is located in heap memory.

IllegalAssignmentError - when the schedulable cannot hold a reference to memory, or when memory cannot hold a reference to this schedulable instance.

Since:

RTSJ 2.0 returns itself

getReleaseParameters

ReleaseParameters<?> getReleaseParameters()

Gets a reference to the ReleaseParameters object for this schedulable.

Returns:

a reference to the current ReleaseParameters object.

setReleaseParameters

Schedulable setReleaseParameters(ReleaseParameters<?> release)

Sets the release parameters associated with this instance of Schedulable.

This change becomes effective under conditions determined by the scheduler controlling the schedulable. For instance, the change may be immediate or it may be delayed until the next release of the schedulable. The different properties of the release parameters may take effect at different times. See the documentation for the scheduler for details.

Parameters:

release - A ReleaseParameters object which will become the release parameters associated with this after the method call, and take effect as determined by the associated scheduler. When null, the default value is governed by the associated scheduler; a new object is created when the default value is not null. (See PriorityScheduler.)

Returns:

this

Throws:

StaticIllegalArgumentException - when release is not compatible with the associated scheduler. Also when this schedulable may not use the heap and release is located in heap memory.

IllegalAssignmentError - when this object cannot hold a reference to release or release cannot hold a reference to this.

IllegalTaskStateException - when the task is running and the new release parameters are not compatible with the current scheduler.

Since:

RTSJ 2.0 returns itself

getScheduler

Scheduler getScheduler()

Gets a reference to the Scheduler object for this schedulable.

Returns:

a reference to the associated Scheduler object.

setScheduler

Schedulable setScheduler(Scheduler scheduler)
                  throws StaticSecurityException,
                         IllegalTaskStateException

Sets the reference to the Scheduler object. The timing of the change must be agreed between the scheduler currently associated with this schedulable, and scheduler. If the Schedulable is running, its associated SchedulingParameters (if any) must be compatible with scheduler.

Parameters:

scheduler - A reference to the scheduler that will manage execution of this schedulable. Null is not a permissible value.

Returns:

this

Throws:

StaticIllegalArgumentException - when scheduler is null, or the schedulable's existing parameter values are not compatible with scheduler. Also when this schedulable may not use the heap and scheduler is located in heap memory.

IllegalAssignmentError - when the schedulable cannot hold a reference to scheduler or the current Schedulable is running and its associated SchedulingParameters are incompatible with scheduler.

StaticSecurityException - when the caller is not permitted to set the scheduler for this schedulable.

IllegalTaskStateException - when scheduler has scheduling or release parameters that are not compatible with the new scheduler and this schedulable is running.

Since:

RTSJ 2.0 returns itself

setScheduler

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

Sets the scheduler and associated parameter objects. The timing of the change must be agreed between the scheduler currently associated with this schedulable, and scheduler.

Parameters:

scheduler - A reference to the scheduler that will manage the execution of this schedulable. Null is not a permissible value.

scheduling - A reference to the SchedulingParameters which will be associated with this. When null, the default value is governed by scheduler; a new object is created when the default value is not null. (See PriorityScheduler.)

release - A reference to the ReleaseParameters which will be associated with this. When null, the default value is governed by scheduler; a new object is created when the default value is not null. (See PriorityScheduler.)

memoryParameters - A reference to the MemoryParameters which will be associated with this. When null, the default value is governed by scheduler; a new object is created when the default value is not null. (See PriorityScheduler.)

Returns:

this

Throws:

StaticIllegalArgumentException - when scheduler is null or the parameter values are not compatible with scheduler. Also thrown when this schedulable may not use the heap and scheduler, scheduling release, memoryParameters, or group is located in heap memory.

IllegalAssignmentError - when this object cannot hold references to all the parameter objects or the parameters cannot hold references to this.

StaticSecurityException - when the caller is not permitted to set the scheduler for this schedulable.

Since:

RTSJ 2.0

getSchedulingParameters

SchedulingParameters getSchedulingParameters()

Gets a reference to the SchedulingParameters object for this schedulable.

Returns:

A reference to the current SchedulingParameters object.

setSchedulingParameters

Schedulable setSchedulingParameters(SchedulingParameters scheduling)
                             throws IllegalTaskStateException,
                                    IllegalAssignmentError,
                                    StaticIllegalArgumentException

Sets the scheduling parameters associated with this instance of Schedulable.

This change becomes effective under conditions determined by the scheduler controlling the schedulable. For instance, the change may be immediate or it may be delayed until the next release of the schedulable. See the documentation of the scheduler for details.

Parameters:

scheduling - A reference to the SchedulingParameters object. When null, the default value is governed by the associated scheduler; a new object is created when the default value is not null. (See PriorityScheduler.). When the Affinity is not defined in scheduling, then the affinity that will be used is the one of the creating Thread. However, this default affinity will not appear when calling getSchedulingParameters(), unless explicitly set using this method.

Returns:

this

Throws:

StaticIllegalArgumentException - when scheduling is not compatible with the associated scheduler. Also when this schedulable may not use the heap and scheduling is located in heap memory.

IllegalAssignmentError - when this object cannot hold a reference to scheduling or scheduling cannot hold a reference to this.

IllegalTaskStateException - when the task is active and the new scheduling parameters are not compatible with the current scheduler or when the task is active and the affinity in scheduling is not a subset of the affinity of this object's RealtimeThreadGroup or when the task is active and the affinity in scheduling is invalid.

Since:

RTSJ 2.0, method returns a reference to this.

getConfigurationParameters

ConfigurationParameters getConfigurationParameters()

Gets a reference to the ConfigurationParameters object for this schedulable.

Returns:

a reference to the associated ConfigurationParameters object.

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.

Parameters:

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

Throws:

java.lang.IllegalThreadStateException - when this schedulable is active.

StaticSecurityException - when the current schedulable cannot modify this event 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

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

getProcessingGroupParameters

@Deprecated
default ProcessingGroupParameters getProcessingGroupParameters()

Deprecated. since RTSJ 2.0

Gets a reference to the ProcessingGroupParameters object for this schedulable.

Returns:

A reference to the current ProcessingGroupParameters object.

setProcessingGroupParameters

@Deprecated
default void setProcessingGroupParameters(ProcessingGroupParameters group)

Deprecated. since RTSJ 2.0; see ProcessingConstraint.

Sets the ProcessingGroupParameters of this.

This change becomes effective under conditions determined by the scheduler controlling the schedulable. For instance, the change may be immediate or it may be delayed until the next release of the schedulable. See the documentation for the scheduler for details.

Parameters:

group - A ProcessingGroupParameters object which will take effect as determined by the associated scheduler. When null, the default value is governed by the associated scheduler (a new object is created when the default value is not null). (See PriorityScheduler.)

Throws:

StaticIllegalArgumentException - when group is not compatible with the scheduler for this schedulable object. Also when this schedulable may not use the heap and group is located in heap memory.

IllegalAssignmentError - when this object cannot hold a reference to group or group cannot hold a reference to this.

java.lang.IllegalThreadStateException - when the schedulable's scheduler prohibits the changing of the processing group parameter at this time due to the state of the schedulable object.

addToFeasibility

@Deprecated
default boolean addToFeasibility()

Deprecated. as of RTSJ 2.0 The framework for feasibility analysis is inadequate.

Informs the scheduler and cooperating facilities that this instance of Schedulable should be considered in feasibility analysis until further notified.

When the object is already included in the feasibility set, does nothing.

Returns:

true, when the resulting system is feasible. False, when not.

removeFromFeasibility

@Deprecated
default boolean removeFromFeasibility()

Deprecated. as of RTSJ 2.0 The framework for feasibility analysis is inadequate

Informs the scheduler and cooperating facilities that this instance of Schedulable should not be considered in feasibility analysis until it is further notified.

Returns:

true when the removal was successful. false when the schedulable cannot be removed from the scheduler's feasibility set; e.g., the schedulable is not part of the scheduler's feasibility set.