javax.realtime.posix

Class SignalDispatcher

java.lang.Object

javax.realtime.ActiveEventDispatcher<SignalDispatcher,Signal>

javax.realtime.posix.SignalDispatcher

public final class SignalDispatcher
extends ActiveEventDispatcher<SignalDispatcher,Signal>

Provides a means of dispatching a set of Signals. An application can provide its own dispatcher, providing the priority for the internal dispatching thread. This dispatching thread calls the AsyncEvent.fire() method on the instance of Signal associated with the signal each time its signal is triggered.

This class requires the following permissions:

Method	Required Action for POSIXPermission
setDefaultDispatcher(javax.realtime.posix.SignalDispatcher)	system

Since:

RTSJ 2.0

See Also:

Signal, POSIXPermission

Constructor Summary

Constructors

Constructor and Description
SignalDispatcher(SchedulingParameters scheduling) Creates a new dispatcher, whose dispatching thread runs with the given SchedulingParameters.
SignalDispatcher(SchedulingParameters scheduling, RealtimeThreadGroup group) Creates a new dispatcher, whose dispatching thread runs with the given SchedulingParameters.

Method Summary

Modifier and Type	Method and Description
protected void	activate(Signal target) Activate an active event registered with this dispatcher.
protected void	deactivate(Signal target) Deactivate an active event registered with this dispatcher.
protected void	deregister(Signal target) Deregisters an active event from this dispatcher, breaking its association with this dispatcher.
void	destroy() Releases all resources thereby making the dispatcher unusable.
static SignalDispatcher	getDefaultDispatcher() Obtain the default dispatcher for signals.
boolean	isRegistered(Signal target) Test wether or not a given event is registered with this dispatcher.
protected void	register(Signal target) Registers an active event with this dispatcher.
static void	setDefaultDispatcher(SignalDispatcher dispatcher) Sets the system default signal dispatcher.

Methods inherited from class javax.realtime.ActiveEventDispatcher

getRealtimeThreadGroup, getScheduler, getSchedulingParameters, getThread, setScheduler, setScheduler, setSchedulingParameters

Methods inherited from class java.lang.Object

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

Constructor Detail

SignalDispatcher

public SignalDispatcher(SchedulingParameters scheduling,
                        RealtimeThreadGroup group)
                 throws StaticIllegalStateException

Creates a new dispatcher, whose dispatching thread runs with the given SchedulingParameters.

Parameters:

scheduling - Parameters for scheduling this dispatcher.

group - Container for this dispatcher.

Throws:

StaticIllegalStateException - when the intersection of affinity in schedule and the affinity of group does not correspond to a valid affinity.

SignalDispatcher

public SignalDispatcher(SchedulingParameters scheduling)
                 throws StaticIllegalStateException

Creates a new dispatcher, whose dispatching thread runs with the given SchedulingParameters.

Parameters:

scheduling - For scheduling this dispatcher.

Throws:

StaticIllegalStateException - when the intersection of affinity in scheduling and the affinity of group does not correspond to a valid affinity.

Method Detail

setDefaultDispatcher

public static void setDefaultDispatcher(SignalDispatcher dispatcher)

Sets the system default signal dispatcher.

Parameters:

dispatcher - An instance to be used when the next signal is started. When null, the signal dispatcher is set to the original system default.

getDefaultDispatcher

public static SignalDispatcher getDefaultDispatcher()

Obtain the default dispatcher for signals.

Returns:

the current default dispatcher

isRegistered

public boolean isRegistered(Signal target)

Test wether or not a given event is registered with this dispatcher.

Specified by:

isRegistered in class ActiveEventDispatcher<SignalDispatcher,Signal>

Parameters:

target - The event to test

Returns:

true when event is registered with this dispatcher.

register

protected void register(Signal target)
                 throws RegistrationException,
                        StaticIllegalStateException

Registers an active event with this dispatcher. Registering an event prevents the event from being programmatically destroyed, but it may not hold the dispatcher from being collected when the dispatcher is in a more deeply nested scope.

Specified by:

register in class ActiveEventDispatcher<SignalDispatcher,Signal>

Parameters:

target - The event to register

Throws:

RegistrationException - when event is already registered.

StaticIllegalStateException - when this object has been destroyed.

activate

protected void activate(Signal target)
                 throws StaticIllegalStateException

Activate an active event registered with this dispatcher.

Overrides:

activate in class ActiveEventDispatcher<SignalDispatcher,Signal>

Parameters:

target - The event to register

Throws:

StaticIllegalStateException - when event is stopped.

deregister

protected void deregister(Signal target)
                   throws DeregistrationException,
                          StaticIllegalStateException

Deregisters an active event from this dispatcher, breaking its association with this dispatcher. This should only happen when an event is assoicated with another dispather.

Specified by:

deregister in class ActiveEventDispatcher<SignalDispatcher,Signal>

Parameters:

target - The event to deregister

Throws:

StaticIllegalStateException - when this object has been destroyed

DeregistrationException

deactivate

protected void deactivate(Signal target)
                   throws StaticIllegalStateException

Deactivate an active event registered with this dispatcher.

Overrides:

deactivate in class ActiveEventDispatcher<SignalDispatcher,Signal>

Parameters:

target - The event to deregister

Throws:

StaticIllegalStateException - when this object has been destroyed.

destroy

public void destroy()
             throws StaticIllegalStateException

Releases all resources thereby making the dispatcher unusable.

Specified by:

destroy in class ActiveEventDispatcher<SignalDispatcher,Signal>

Throws:

StaticIllegalStateException - when called on a dispatcher that has one or more registered Signal objects.