ptolemy.actor.lib
Class Select

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.Select

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 Select
extends Transformer

A polymorphic select, which routes specified input channels to the output. This actor has two input ports, the input port for data, and the control port to select which input channel to read. In an iteration, if an input token is available at the control input, that token is read, and its value is noted. Its value specifies the input channel that should be read next. If an input token is available on the specified channel of the input port, then that token is read and sent to the output.

The actor indicates a willingness to fire in its prefire() method if there is an input available on the channel specified by the most recently seen token on the control port. If no token has ever been received on the control port, then channel zero is assumed to be the one to read. If the value of the most recently received token on the control port is out of range (less than zero, or greater than or equal to the width of the input), then the actor will not fire() (although it will continue to consume tokens on the control port in its prefire() method).

This actor is similar to the Multiplexor actor, except that it never discards input tokens. Tokens on channels that are not selected are not consumed.

Note that in the DE domain, where this actor is commonly used, if a new value is given to the control port, then all previously unread input tokens on the specified input channel will be read at the same firing time, in the order in which they arrived.

Since:

Ptolemy II 1.0

Version:

$Id: Select.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Edward A. Lee

See Also:

Serialized Form

Accepted Rating:

Yellow (liuj)

Proposed Rating:

Green (neuendor)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private int	_control
TypedIOPort	control Input port for control tokens, which specify the output channel to produce data on.

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

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

Method Summary

void	fire() Read an input token from the specified input channel and produce it on the output.
void	initialize() Initialize this actor so that channel zero of input is read from until a token arrives on the control input.
boolean	prefire() Read a control token, if there is one, and check to see whether an input is available on the input channel specified by the most recent control token, if it is in range.

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, clone, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, 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

_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, postfire, 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

control

public TypedIOPort control

Input port for control tokens, which specify the output channel to produce data on. The type is int.

_control

private int _control

Constructor Detail

Select

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

Construct an actor in the specified container with the specified name.

Parameters:

container - The container.

name - The name of this actor within the container.

Throws:

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

NameDuplicationException - If the name coincides with an actor already in the container.

Method Detail

fire

public void fire()
          throws IllegalActionException

Read an input token from the specified input channel and produce it on the output.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is no director.

initialize

public void initialize()
                throws IllegalActionException

Initialize this actor so that channel zero of input is read from until a token arrives on the control input.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If the parent class throws it.

prefire

public boolean prefire()
                throws IllegalActionException

Read a control token, if there is one, and check to see whether an input is available on the input channel specified by the most recent control token, if it is in range. Return false if there is no input token to read. Otherwise, return whatever the superclass returns.

Specified by:

prefire in interface Executable

Overrides:

prefire in class AtomicActor

Returns:

True if the actor is ready to fire.

Throws:

IllegalActionException - If there is no director.