public class TimedPNDirector extends PNDirector
The thread that calls the various execution methods (initialize, prefire, fire and postfire) on the director is referred to as the directing thread. This directing thread might be the main thread responsible for the execution of the entire simulation or might be the thread created by the executive director of the containing composite actor.
In the PN domain, the director creates a thread (an instance of ProcessThread), representing a Kahn process, for each actor in the model. The threads are created in initialize() and started in the prefire() method of the ProcessDirector. A process is considered active from its creation until its termination. An active process can block when trying to read from a channel (read-blocked), when trying to write to a channel (write-blocked), or when waiting for time to progress (time-blocked). Time can progress for an active process in this model of computation only when the process is blocked.
A deadlock is when all the active processes are blocked. The director is responsible for handling deadlocks during execution. This director handles three different sorts of deadlocks, real deadlock, timed deadlock and artificial deadlock.
A real deadlock is when all the processes are blocked on a read meaning that no process can proceed until it receives new data. The execution can be terminated, if desired, in such a situation. If the container of this director does not have any input ports (as is in the case of a top-level composite actor), then the executive director or manager terminates the execution. If the container has input ports, then it is up to the executive director of the container to decide on the termination of the execution. To terminate the execution after detection of a real deadlock, the manager or the executive director calls wrapup() on the director.
An artificial deadlock is when all processes are blocked and at least one process is blocked on a write. In this case the director increases the capacity of the receiver with the smallest capacity amongst all the receivers on which a process is blocked on a write. This breaks the deadlock and the execution can proceed.
A timed deadlock is when all the processes under the control of this director are blocked, at least one process is blocked on a delay (time-blocked) and no process is blocked on a write. This director supports a notion of global time. All active processes that are not blocked and are executing concurrently are executing at the same global time. A process that wants time to advance, suspends itself by calling the fireAt() method of the director and specifies the time it wants to be awakened at. Time can advance only when a timed deadlock occurs. In such a case, the director advances time to the time when the first timed-blocked process can be awakened.
NamedObj.ContainedObjectsIterator| Modifier and Type | Field and Description |
|---|---|
protected int |
_delayBlockCount
The number of time-blocked processes.
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protected CalendarQueue |
_eventQueue
The priority queue that stores the list of processes waiting for time
to advance.
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_readBlockedQueues, _receivers, _writeBlockedQueues, initialQueueCapacity, maximumQueueCapacity, READ_BLOCKED, WRITE_BLOCKED_newActorThreadList, _notDone_actorsFinishedExecution, _aspectForActor, _aspectsPresent, _defaultMicrostep, _executionAspects, _finishRequested, _initializables, _nextScheduleTime, _stopRequested, _tokenSentToCommunicationAspect, _zeroTime, localClock, startTime, stopTime_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _deferChangeRequests, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKSCOMPLETED, NOT_READY, STOP_ITERATING| Constructor and Description |
|---|
TimedPNDirector()
Construct a director in the default workspace with an empty string
as its name.
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TimedPNDirector(CompositeEntity container,
java.lang.String name)
Construct a director in the given container with the given name.
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TimedPNDirector(Workspace workspace)
Construct a director in the workspace with an empty name.
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| Modifier and Type | Method and Description |
|---|---|
protected boolean |
_areThreadsDeadlocked()
Return true if a deadlock is detected.
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protected void |
_informOfDelayBlock()
Increment by 1 the count of actors waiting for the time to advance.
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protected void |
_informOfDelayUnblock()
Decrease by 1 the count of processes blocked on a delay.
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protected boolean |
_resolveDeadlock()
Return false on detection of a real deadlock.
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java.lang.Object |
clone(Workspace workspace)
Clone the director into the specified workspace.
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Time |
fireAt(Actor actor,
Time newFiringTime,
int microstep)
Suspend the calling process until the time has advanced to at least the
time specified by the method argument.
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void |
setModelTime(Time newTime)
Set a new value to the current time of the model, where
the new time must be no earlier than the current time.
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void |
wrapup()
Reset private variables.
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_incrementLowestWriteCapacityPort, _resolveInternalDeadlock, addProcessListener, initialize, newReceiver, postfire, preinitialize, removeProcessListener, suggestedModalModelDirectors, supportMultirateFiring, threadBlocked, threadUnblocked_areActorsExternallyBlocked, _controllerBlocked, _controllerUnBlocked, _isInputControllerBlocked, _isOutputControllerBlocked, createBranchController, getInputController, getOutputController, prefire, stopInputBranchController, stopOutputBranchController, threadBlocked, threadUnblocked_areAllThreadsStopped, _getActiveThreadsCount, _getBlockedThreadsCount, _getStoppedThreadsCount, _newProcessThread, _requestFinishOnReceivers, addThread, finish, fire, initialize, isStopFireRequested, isThreadActive, removeThread, stop, stopFire, terminate, threadHasPaused, threadHasResumed, transferInputs, transferOutputs_actorFinished, _consultTimeRegulators, _description, _isEmbedded, _isTopLevel, _schedule, _transferInputs, _transferOutputs, addInitializable, attributeChanged, createSchedule, defaultDependency, delayDependency, elapsedTimeSinceStart, fireAt, fireAt, fireAtCurrentTime, fireContainerAt, fireContainerAt, getCausalityInterface, getCurrentTime, getDeadline, getEnvironmentTime, getExecutionAspect, getGlobalTime, getModelNextIterationTime, getModelStartTime, getModelStopTime, getModelTime, getNextIterationTime, getStartTime, getStopTime, getTimeResolution, implementsStrictActorSemantics, invalidateResolvedTypes, invalidateSchedule, isEmbedded, isFireFunctional, isStopRequested, isStrict, iterate, mutexLockObject, notifyTokenSentToCommunicationAspect, preinitialize, removeInitializable, requestInitialization, resume, resumeActor, scheduleContainedActors, setContainer, setCurrentTime, setEmbedded, setTimeResolution, suspend, transferOutputs_checkContainer, _getContainedObject, _propagateExistence, getContainer, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, setName, updateContent_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _containedDecorators, _copyChangeRequestList, _debug, _debug, _debug, _debug, _debug, _executeChangeRequests, _exportMoMLContents, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _notifyHierarchyListenersAfterChange, _notifyHierarchyListenersBeforeChange, _propagateValue, _removeAttribute, _splitName, _stripNumericSuffix, _validateSettables, addChangeListener, addDebugListener, addHierarchyListener, attributeDeleted, attributeList, attributeList, attributeTypeChanged, clone, containedObjectsIterator, decorators, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getElementName, getFullName, getModelErrorHandler, getName, getName, getPrototypeList, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, notifyOfNameChange, propagateExistence, propagateValue, propagateValues, removeAttribute, removeChangeListener, removeDebugListener, removeHierarchyListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, uniqueName, validateSettables, workspaceprotected CalendarQueue _eventQueue
protected int _delayBlockCount
public TimedPNDirector()
throws IllegalActionException,
NameDuplicationException
IllegalActionException - If the name has a period in it, or
the director is not compatible with the specified container.NameDuplicationException - If the container already contains
an entity with the specified name.public TimedPNDirector(Workspace workspace) throws IllegalActionException, NameDuplicationException
workspace - The workspace of this object.IllegalActionException - If the name has a period in it, or
the director is not compatible with the specified container.NameDuplicationException - If the container already contains
an entity with the specified name.public TimedPNDirector(CompositeEntity container, java.lang.String name) throws IllegalActionException, NameDuplicationException
container - Container of the director.name - Name of this director.IllegalActionException - If the director is not compatible
with the specified container. May be thrown in derived classes.NameDuplicationException - If the container not a
CompositeActor and the name collides with an entity in the container.public java.lang.Object clone(Workspace workspace) throws java.lang.CloneNotSupportedException
clone in class PNDirectorworkspace - The workspace for the cloned object.java.lang.CloneNotSupportedException - If one of the attributes
cannot be cloned.NamedObj.exportMoML(Writer, int, String),
NamedObj.setDeferringChangeRequests(boolean)public Time fireAt(Actor actor, Time newFiringTime, int microstep) throws IllegalActionException
fireAt in class Directoractor - The actor scheduled to be fired.newFiringTime - The scheduled time.microstep - The microstep (ignored by this director).IllegalActionException - If the operation is not
permissible (e.g. the given time is in the past).Director.fireAtCurrentTime(Actor),
Director.fireContainerAt(Time)public void setModelTime(Time newTime) throws IllegalActionException
setModelTime in class DirectornewTime - The new time of the model.IllegalActionException - If an attempt is made to change the
time to less than the current time.Director.getModelTime()public void wrapup()
throws IllegalActionException
wrapup in interface Initializablewrapup in class CompositeProcessDirectorIllegalActionException - If an error occurs while
accessing the receivers of all actors under the control of
this director.protected boolean _areThreadsDeadlocked()
_areThreadsDeadlocked in class CompositeProcessDirectorprotected void _informOfDelayBlock()
protected void _informOfDelayUnblock()
protected boolean _resolveDeadlock()
throws IllegalActionException
_resolveDeadlock in class CompositeProcessDirectorIllegalActionException - Not thrown in this base class.
This might be thrown by derived classes.