ptolemy.domains.csp.lib
Class ResourcePool

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.domains.csp.kernel.CSPActor
                              ptolemy.domains.csp.lib.ResourcePool

All Implemented Interfaces:

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

public class ResourcePool
extends CSPActor

This actor manages a pool of resources, where each resource is represented by a token with an arbitrary value. Resources are granted on the grant output port and released on the release input port. These ports are both multiports, so resources can be granted to multiple users of the resources, and released by multiple actors.

The initial pool of resources is provided by the initialPool parameter, which is an array of arbitrary type. The grant output port and release input port are constrained to have compatible types. Specifically, the grant output port must be able to send tokens with types that match the elements of this array, and it must also be able to send tokens with types that match inputs provided at the release input.

This actor is designed for use in the CSP domain, where it will execute in its own thread. At all times, it is ready to rendezvous with any other actor connected to its release input port. When such a rendezvous occurs, the token provided at that input is added to the resource pool. In addition, whenever the resource pool is non-empty, this actor is ready to rendezvous with any actor connected to its grant output port. When such a rendezvous occurs, it sends the first token in the resource pool to that output port and removes that token from the resource pool.

Since:

Ptolemy II 5.2

Version:

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

Author:

Edward A. Lee

See Also:

Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Yellow (eal)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private boolean	_branchEnabled Indicator that a branch was successfully enabled in the fire() method.
private java.util.List	_pool The current resource pool.
private static boolean	_VERBOSE_DEBUGGING Flag to set verbose debugging messages.
TypedIOPort	grant The output port through which this actor grants resources.
Parameter	initialPool The initial resource pool.
TypedIOPort	release The input port through which other actors release resources.

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

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

Method Summary

void	attributeChanged(Attribute attribute) Override the base class to reset the resource pool to match the specified initialPool value.
java.lang.Object	clone(Workspace workspace) Override the base class to set the type constraints.
void	fire() If there are available resources, then perform a conditional branch on any release input or grant output.
boolean	postfire() Return true unless none of the branches were enabled in the most recent invocation of fire().

Methods inherited from class ptolemy.domains.csp.kernel.CSPActor

_cancelDelay, _continue, _waitForDeadlock, chooseBranch, delay, getBranchController, initialize, terminate

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, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, 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, 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

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

grant

public TypedIOPort grant

The output port through which this actor grants resources. This port has type equal to the element type of the initialPool parameter.

release

public TypedIOPort release

The input port through which other actors release resources. This port has type equal to the element type of the initialPool parameter.

initialPool

public Parameter initialPool

The initial resource pool. This is an array with default value {1} (an integer array with one entry with value 1).

_pool

private java.util.List _pool

The current resource pool.

_branchEnabled

private boolean _branchEnabled

Indicator that a branch was successfully enabled in the fire() method.

_VERBOSE_DEBUGGING

private static boolean _VERBOSE_DEBUGGING

Flag to set verbose debugging messages.

Constructor Detail

ResourcePool

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

Construct an actor in the specified container with the specified name. The name must be unique within the container or an exception is thrown. The container argument must not be null, or a NullPointerException will be thrown.

Parameters:

container - The container.

name - The name.

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

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

Override the base class to reset the resource pool to match the specified initialPool value.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If the change is not acceptable to this container (not thrown in this base class).

clone

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

Override the base class to set the type constraints.

Overrides:

clone in class CSPActor

Parameters:

workspace - The workspace for the cloned object.

Returns:

A new ResourcePool actor.

Throws:

java.lang.CloneNotSupportedException - If cloned ports cannot have as their container the cloned entity (this should not occur), or if one of the attributes cannot be cloned.

See Also:

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

fire

public void fire()
          throws IllegalActionException

If there are available resources, then perform a conditional branch on any release input or grant output. If the selected branch is a release input, then add the provided token to the end of the resource pool. If it is a grant output, then remove the first element from the resource pool and send it to the output. If there are no available resources, then perform a conditional branch only on the release inputs.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If an error occurs during executing the process.

TerminateProcessException - If the process termination is requested by the director.

postfire

public boolean postfire()

Return true unless none of the branches were enabled in the most recent invocation of fire().

Specified by:

postfire in interface Executable

Overrides:

postfire in class CSPActor

Returns:

True if another iteration can occur.