public class Default extends TypedAtomicActor
When the preferred input has a token, then the output is equal to that token. If the preferred input is absent, then the output is equal to the alternate input (whether it is absent or not). This actor is non-strict, in that can produce an output even if alternate input is unknown. Thus, it can be used to break causality loops.
This actor is inspired by the "default" operator in the synchronous language SIGNAL, and is similar to the "followed by" operator in Lustre. But in the context of the Ptolemy II SR domain, its behavior is deterministic. This is because the Ptolemy II SR domain has a Lustre or Esterel style master clock, and this actor is given the opportunity to fire on each tick of that master clock. In SIGNAL, by contrast, this actor can be used to "upsample" to a higher rate clock; however, without considerable care, its use in SIGNAL results in nondeterminism.
This actor is typically used in the SR domain, but may also be used inside the Continuous domain.
P. Caspi, D. Pilaud, N. Halbwachs, and J. A. Plaice, "LUSTRE: A Declarative Language for Programming Synchronous Systems," Conference Record of the 14th Annual ACM Symp. on Principles of Programming Languages, Munich, Germany, January, 1987.
A. Benveniste and P. Le Guernic, "Hybrid Dynamical Systems Theory and the SIGNAL Language," IEEE Tr. on Automatic Control, Vol. 35, No. 5, pp. 525-546, May 1990.
Entity.ContainedObjectsIterator| Modifier and Type | Field and Description |
|---|---|
TypedIOPort |
alternate
The alternate input port.
|
TypedIOPort |
output
The output port.
|
TypedIOPort |
preferred
The preferred input port.
|
_typesValid_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _deferChangeRequests, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKSCOMPLETED, NOT_READY, STOP_ITERATING| Constructor and Description |
|---|
Default(CompositeEntity container,
java.lang.String name)
Construct an actor in the specified container with the specified
name.
|
| Modifier and Type | Method and Description |
|---|---|
void |
fire()
If the preferred input is known and present, then its token is
sent to the output port.
|
boolean |
isStrict()
Return false.
|
void |
preinitialize()
Override the base class to declare that the output
does not depend on the alternate in a firing.
|
_containedTypeConstraints, _customTypeConstraints, _defaultTypeConstraints, _fireAt, _fireAt, attributeTypeChanged, clone, clone, isBackwardTypeInferenceEnabled, newPort, typeConstraintList, typeConstraints_actorFiring, _actorFiring, _declareDelayDependency, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, initialize, inputPortList, isFireFunctional, iterate, newReceiver, outputPortList, postfire, prefire, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName_addPort, _description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition_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, workspaceequals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitcreateReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortListisFireFunctional, iterate, postfire, prefire, stop, stopFire, terminateaddInitializable, initialize, removeInitializable, wrapupdescription, getContainer, getDisplayName, getFullName, getName, getName, setNamegetDerivedLevel, getDerivedList, propagateValuepublic TypedIOPort preferred
public TypedIOPort alternate
public TypedIOPort output
public Default(CompositeEntity container, java.lang.String name) throws IllegalActionException, NameDuplicationException
container - The container.name - The name of this actor within the container.IllegalActionException - If the actor cannot be contained
by the proposed container.NameDuplicationException - If the name coincides with
an actor already in the container.public void fire()
throws IllegalActionException
fire in interface Executablefire in class AtomicActor<TypedIOPort>IllegalActionException - If there is no director.public boolean isStrict()
isStrict in interface ExecutableisStrict in class AtomicActor<TypedIOPort>public void preinitialize()
throws IllegalActionException
preinitialize in interface Initializablepreinitialize in class AtomicActor<TypedIOPort>IllegalActionException - If the superclass throws it.