ptolemy.actor.lib

Class MicrostepDelay

java.lang.Object

ptolemy.kernel.util.NamedObj

ptolemy.kernel.InstantiableNamedObj

ptolemy.kernel.Entity<T>

ptolemy.kernel.ComponentEntity<T>

ptolemy.actor.AtomicActor<TypedIOPort>

ptolemy.actor.TypedAtomicActor

ptolemy.actor.lib.Transformer

ptolemy.actor.lib.MicrostepDelay

All Implemented Interfaces:

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

public class MicrostepDelay
extends Transformer

This actor delays the input by one microstep. The output is always absent in the first firing. This actor is designed to be used in domains where the director implements SuperdenseTimeDirector, like Continuous and DE. Inputs are read only during the postfire() method. If an input is present, then this actor schedules itself to fire again to produce the just received token on the corresponding output channel in the next microstep at the same time stamp.

When this actor is used in the Continuous domain, it requires that its input be purely discrete (specifically that it be absent at microstep 0). The reason for rejecting continuous inputs is that a continuous input would cause a stuttering Zeno condition, where time cannot advance.

Since:

Ptolemy II 10.0

Version:

$Id$

Author:

Edward A. Lee

Pt.AcceptedRating:

Red (eal)

Pt.ProposedRating:

Yellow (eal)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

Fields

Modifier and Type	Field and Description
protected Token	_pendingOutput A token to send in the next microstep.

Fields inherited from class ptolemy.actor.lib.Transformer

input, output

Fields inherited from class ptolemy.actor.TypedAtomicActor

_typesValid

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _deferChangeRequests, _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

Constructors

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

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone(Workspace workspace) Clone the actor into the specified workspace.
void	declareDelayDependency() Declare that the output does not depend on the input in a firing.
void	fire() Read one token from the input.
void	initialize() Initialize the states of this actor.
boolean	isStrict() Return false indicating that this actor can be fired even if the inputs are unknown.
boolean	postfire() Read the input, if there is one, and request refiring.

Methods inherited from class ptolemy.actor.TypedAtomicActor

_containedTypeConstraints, _customTypeConstraints, _defaultTypeConstraints, _fireAt, _fireAt, attributeTypeChanged, clone, isBackwardTypeInferenceEnabled, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, _declareDelayDependency, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, iterate, newReceiver, outputPortList, prefire, preinitialize, 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

_addPort, _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, _containedDecorators, _copyChangeRequestList, _debug, _debug, _debug, _debug, _debug, _executeChangeRequests, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _notifyHierarchyListenersAfterChange, _notifyHierarchyListenersBeforeChange, _propagateValue, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, addHierarchyListener, attributeChanged, attributeDeleted, attributeList, attributeList, decorators, 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, notifyOfNameChange, propagateValue, propagateValues, removeAttribute, removeChangeListener, removeDebugListener, removeHierarchyListener, 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, iterate, prefire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, preinitialize, 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

_pendingOutput

protected Token _pendingOutput

A token to send in the next microstep.

Constructor Detail

MicrostepDelay

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

Construct an actor with the specified container and name. Constrain that the output type to be the same as the input type.

Parameters:

container - The composite entity to contain this one.

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. Set a type constraint that the output type is the same as the that of input.

Overrides:

clone in class TypedAtomicActor

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)

declareDelayDependency

public void declareDelayDependency()
                            throws IllegalActionException

Declare that the output does not depend on the input in a firing.

Overrides:

declareDelayDependency in class AtomicActor<TypedIOPort>

Throws:

IllegalActionException - If the causality interface cannot be computed.

See Also:

AtomicActor.getCausalityInterface()

fire

public void fire()
          throws IllegalActionException

Read one token from the input. Send out a token that is scheduled to be produced at the current time.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor<TypedIOPort>

Throws:

IllegalActionException - If there is no director, or the input can not be read, or the output can not be sent.

initialize

public void initialize()
                throws IllegalActionException

Initialize the states of this actor.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor<TypedIOPort>

Throws:

IllegalActionException - If the director does not implement SuperdenseTimeDirector.

isStrict

public boolean isStrict()

Return false indicating that this actor can be fired even if the inputs are unknown.

Specified by:

isStrict in interface Executable

Overrides:

isStrict in class AtomicActor<TypedIOPort>

Returns:

False.

postfire

public boolean postfire()
                 throws IllegalActionException

Read the input, if there is one, and request refiring.

Specified by:

postfire in interface Executable

Overrides:

postfire in class AtomicActor<TypedIOPort>

Returns:

True if execution can continue into the next iteration.

Throws:

IllegalActionException - If scheduling to refire cannot be performed, or if there is input and the current microstep is zero, or if the superclass throws it.