ptolemy.actor.lib
Class ResettableTimer

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.actor.lib.Transformer
                              ptolemy.actor.lib.ResettableTimer

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

public class ResettableTimer
extends Transformer

Produce an output after the time specified on the input has elapsed. If the input value is 0.0, then the output will be produced at the next superdense time index (i.e., on the next firing, but at the current time). If the input is negative, this actor will cancel the previously requested output, if it has not yet been produced by the time the negative input is received. The value of the output is specified by the value parameter.

If the preemptive parameter is true (the default), then if a new input arrives before the previous timer request has expired, then that timer request is canceled. If an input arrives at the same time that the previous timer request expires, an output is produced immediately. The timer request is not cancelled.

If the preemptive parameter is false, then the new input will cause the timer to start only after the currently pending timer (if any is pending) expires.

When the preemptive parameter is true, this actor resembles the VariableDelay actor in the DE domain, except that arrivals of new inputs before the delay has expired causes the previously scheduled output to be canceled. Also, the output value is given in this actor by the value parameter instead of by the input.

When the preemptive parameter is false, this actor resembles the Server actor in the DE domain, except that the time delay is specified by the single input. The Server actor, by contrast, has separate inputs for service time and payload, and the service time experienced by a payload depends on the most recently arrived service time input at the time that the payload service begins, not at the time the payload arrives.

If this actor is used in a modal model and is in a mode that is not active for some time, then no outputs will be produced for the times it is inactive. If it becomes active again before the scheduled time to produce an output, then it will produce that output. If it is not preemptive, then upon becoming active again, it will behave as if it had been active during the intervening time, calculating when the outputs should have been produced, and discarding them if the calculated time falls in the inactive period.

Since:

Ptolemy II 8.0

Version:

$Id: ResettableTimer.java 57044 2010-01-27 22:41:05Z cxh $

Author:

Edward A. Lee

See Also:

Serialized Form

Accepted Rating:

Red (eal)

Proposed Rating:

Yellow (eal)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.Entity

Entity.ContainedObjectsIterator

Field Summary

private int	_pendingOutputMicrostep Pending output microstep.
private Time	_pendingOutputTime Pending output time.
private CalendarQueue	_pendingRequests A local queue to store the pending requests.
Parameter	preemptive Indicator of whether new inputs cancel previous requests.
Parameter	value The value produced at the output.

Fields inherited from class ptolemy.actor.lib.Transformer

input, output

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS

Fields inherited from interface ptolemy.actor.Executable

COMPLETED, NOT_READY, STOP_ITERATING

Constructor Summary

ResettableTimer(CompositeEntity container, java.lang.String name)
Construct an actor with the specified container and name.

Method Summary

java.lang.Object	clone(Workspace workspace) Clone the actor into the specified workspace.
void	fire() If an output is scheduled to be produced, then produce it.
void	initialize() Initialize the internal states of this actor.
boolean	postfire() Read the input (if any) and schedule a future output.
void	preinitialize() Override the base class to declare that the output does not depend on the input in a firing.

Methods inherited from class ptolemy.actor.TypedAtomicActor

_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, prefire, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup

Methods inherited from class ptolemy.kernel.ComponentEntity

_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName

Methods inherited from class ptolemy.kernel.Entity

_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeChanged, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.actor.Actor

createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

isFireFunctional, isStrict, iterate, prefire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, removeInitializable, wrapup

Methods inherited from interface ptolemy.kernel.util.Nameable

description, getContainer, getDisplayName, getFullName, getName, getName, setName

Methods inherited from interface ptolemy.kernel.util.Derivable

getDerivedLevel, getDerivedList, propagateValue

Field Detail

preemptive

public Parameter preemptive

Indicator of whether new inputs cancel previous requests. This is a boolean that defaults to true.

value

public Parameter value

The value produced at the output. This can have any type, and it defaults to a boolean token with value true.

_pendingOutputTime

private Time _pendingOutputTime

Pending output time.

_pendingOutputMicrostep

private int _pendingOutputMicrostep

Pending output microstep.

_pendingRequests

private CalendarQueue _pendingRequests

A local queue to store the pending requests.

Constructor Detail

ResettableTimer

public ResettableTimer(CompositeEntity container,
                       java.lang.String name)
                throws NameDuplicationException,
                       IllegalActionException

Construct an actor with the specified container and name. Declare that the input can only receive double tokens and the output has a data type the same as the value parameter.

Parameters:

container - The container.

name - The name of this actor.

Throws:

IllegalActionException - If the entity cannot be contained by the proposed container.

NameDuplicationException - If the container already has an actor with this name.

Method Detail

clone

public java.lang.Object clone(Workspace workspace)
                       throws java.lang.CloneNotSupportedException

Clone the actor into the specified workspace. This calls the base class and links the type of the value parameter to the output.

Overrides:

clone in class AtomicActor

Parameters:

workspace - The workspace for the new object.

Returns:

A new actor.

Throws:

java.lang.CloneNotSupportedException - If a derived class has has an attribute that cannot be cloned.

See Also:

NamedObj.exportMoML(Writer, int, String), NamedObj.setDeferringChangeRequests(boolean)

fire

public void fire()
          throws IllegalActionException

If an output is scheduled to be produced, then produce it.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is no director, or can not send or get tokens from ports.

initialize

public void initialize()
                throws IllegalActionException

Initialize the internal states of this actor.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If a derived class throws it.

postfire

public boolean postfire()
                 throws IllegalActionException

Read the input (if any) and schedule a future output.

Specified by:

postfire in interface Executable

Overrides:

postfire in class AtomicActor

Returns:

True if execution can continue into the next iteration.

Throws:

IllegalActionException - If reading the input, or requesting a refiring throws it.

preinitialize

public void preinitialize()
                   throws IllegalActionException

Override the base class to declare that the output does not depend on the input in a firing.

Specified by:

preinitialize in interface Initializable

Overrides:

preinitialize in class AtomicActor

Throws:

IllegalActionException - If the superclass throws it.