ptolemy.domains.ddf.lib
Class DDFSelect

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.domains.ddf.lib.DDFSelect

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 DDFSelect
extends TypedAtomicActor

A type polymorphic select, which routes specified input channels to the output, used in the DDF domain. In the first iteration, an input token at the control port is read and its value is recorded. In the second iteration, an input token is read from the input port channel specified by the most recently seen token at the control port and sent to the output. It alternates between these two kinds of iterations until stopped. The control port must receive IntTokens. The input port may receive tokens of any type. Because tokens are immutable, the same token is sent to the output, rather than a copy. Note that as for any multiport, the channel number starts from 0 and increments by 1 for each additional channel in the order the channel is created (e.g., when a connection is drawn in Vergil).

Note this actor sends an output token every two iterations. Contrast this with Select which sends an output token every iteration.

Since:

Ptolemy II 4.1

Version:

$Id: DDFSelect.java 53042 2009-04-10 20:31:21Z cxh $

Author:

Gang Zhou

See Also:

Serialized Form

Accepted Rating:

Yellow (cxh)

Proposed Rating:

Yellow (zgang)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private int	_control The most recently read control token.
private boolean	_isControlRead The boolean to determine whether to read from the control port or from the input port.
private static IntToken	_one A final static IntToken with value 1.
private ArrayToken[]	_rateArray An array of ArrayTokens to be used to set tokenConsumptionRate of the input port.
private ArrayToken	_rateZero An ArrayToken to be used to set tokenConsumptionRate of the input port.
private static IntToken	_zero A final static IntToken with value 0.
TypedIOPort	control The input port for control tokens, which specifies the input channels to read the tokens from.
Parameter	control_tokenConsumptionRate This parameter provides token consumption rate for control.
TypedIOPort	input The input port.
Parameter	input_tokenConsumptionRate This parameter provides token consumption rate for input.
TypedIOPort	output The output port.

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

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

Method Summary

java.lang.Object	clone(Workspace workspace) Clone the actor into the specified workspace.
void	connectionsChanged(Port port) Pre-calculate the rates to be set in the rate parameter of the input port.
void	fire() Fire the actor once.
void	initialize() Initialize this actor and rate parameters so that it will read from the control port in the first iteration.
boolean	postfire() Update rate parameters for the next iteration.
boolean	prefire() Return false if the port or channel it needs to read from in the following firing does not have a token.

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

input

public TypedIOPort input

The input port. The port type can be any type.

control

public TypedIOPort control

The input port for control tokens, which specifies the input channels to read the tokens from. The type is int.

output

public TypedIOPort output

The output port. The type is at least the type of input.

input_tokenConsumptionRate

public Parameter input_tokenConsumptionRate

This parameter provides token consumption rate for input. The type is array of ints.

control_tokenConsumptionRate

public Parameter control_tokenConsumptionRate

This parameter provides token consumption rate for control. The type is int.

_control

private int _control

The most recently read control token.

_isControlRead

private boolean _isControlRead

The boolean to determine whether to read from the control port or from the input port.

_one

private static final IntToken _one

A final static IntToken with value 1.

_zero

private static final IntToken _zero

A final static IntToken with value 0.

_rateArray

private ArrayToken[] _rateArray

An array of ArrayTokens to be used to set tokenConsumptionRate of the input port. Each ArrayToken indicates the input port needs to consume one token from a corresponding channel and no token from the rest of the channels. The array is initialized in the method connectionsChanged().

_rateZero

private ArrayToken _rateZero

An ArrayToken to be used to set tokenConsumptionRate of the input port. It indicates the input port does not consume any token from any channel. This variable is initialized in the method connectionsChanged().

Constructor Detail

DDFSelect

public DDFSelect(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

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 then sets the type constraints.

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 an attribute that cannot be cloned.

See Also:

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

connectionsChanged

public void connectionsChanged(Port port)

Pre-calculate the rates to be set in the rate parameter of the input port. Initialize the private variables _rateZero, which indicates the input port does not consume any token from any channel, and _rateArray, each element of which indicates the input port needs to consume one token from a corresponding channel and no token from the rest of the channels.

Overrides:

connectionsChanged in class AtomicActor

Parameters:

port - The port that has connection changes.

fire

public void fire()
          throws IllegalActionException

Fire the actor once. If the control port is not read in the previous iteration, read a new token from the control port and record the value of the token and this concludes the current firing. Otherwise output the token consumed from the input port channel specified by the most recently seen token on the control port. Then reset an internal variable so that it will read from the control port in the next iteration.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is no director, and hence no receivers have been created, or the value of the received control token is out of range.

initialize

public void initialize()
                throws IllegalActionException

Initialize this actor and rate parameters so that it will read from the control port in the first iteration.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If setToken() throws it.

postfire

public boolean postfire()
                 throws IllegalActionException

Update rate parameters for the next iteration.

Specified by:

postfire in interface Executable

Overrides:

postfire in class AtomicActor

Returns:

True if execution can continue into the next iteration.

Throws:

IllegalActionException - If setToken() throws it.

prefire

public boolean prefire()
                throws IllegalActionException

Return false if the port or channel it needs to read from in the following firing does not have a token. Otherwise, return whatever the superclass returns.

Specified by:

prefire in interface Executable

Overrides:

prefire in class AtomicActor

Returns:

True if there are enough tokens to fire.

Throws:

IllegalActionException - If the receivers do not support the query, or if there is no director, and hence no receivers.