/* A base class for threaded DE domain actors.
Copyright (c) 1998-2009 The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without
license or royalty fees, to use, copy, modify, and distribute this
software and its documentation for any purpose, provided that the above
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of this software.
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*/
package ptolemy.domains.de.kernel;
import java.util.Iterator;
import ptolemy.actor.IOPort;
import ptolemy.actor.TypedCompositeActor;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.InternalErrorException;
import ptolemy.kernel.util.KernelException;
import ptolemy.kernel.util.NameDuplicationException;
import ptolemy.kernel.util.PtolemyThread;
//////////////////////////////////////////////////////////////////////////
//// DEThreadActor
/**
A base class for threaded DE domain actors.
<P>
NOTE: This actor is very preliminary. It is not developed and maintained
for a long time. We do not recommend using it. To try multiple threads under
DE semantics, use DDE domain, which is another experimental domain.
<P>
This actor, upon its initialization, will start another thread.
The thread communicate with the DEDirector thread by placing
events into the DEEventQueue asynchronously.
<P>
Subclass of this class should implement the run() method.
The subclass is executed in an event driven way. More precisely,
the implementation of the run() method should call
waitForNewInputs() after processing all current events. The
calls are blocked until the next time fire() is called.
Recall that the Director (after putting events into the
receiver of the input ports) will call fire() on the actor.
NOTE: The synchronization mechanism is implemented in DECQEventQueue
to ensure the correct multi-threading behaviour.
<P>
This implementation does not change the semantics of DEReceiver,
but still supports an asynchronous message passing type of
concurrency.
@author Lukito Muliadi
@version $Id$
@since Ptolemy II 0.2
@Pt.ProposedRating Red (lmuliadi)
@Pt.AcceptedRating Red (cxh)
@see DEActor
*/
public abstract class DEThreadActor extends DEActor implements Runnable {
/** Constructor.
* @param container The container.
* @param name The name of this actor.
* @exception IllegalActionException If the entity cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the container already has an
* actor with this name.
*/
public DEThreadActor(TypedCompositeActor container, String name)
throws NameDuplicationException, IllegalActionException {
super(container, name);
}
///////////////////////////////////////////////////////////////////
//// public methods ////
/** Awake the thread running this actor.
*/
public void fire() {
synchronized (_monitor) {
// Set the flag to false, to make sure only this actor wakes up.
_isWaiting = false;
_monitor.notifyAll();
// then wait until this actor go to wait.
while (!_isWaiting) {
try {
_monitor.wait();
} catch (InterruptedException e) {
System.err.println(KernelException.stackTraceToString(e));
}
}
}
}
/** Create a thread for the actor and start the thread.
*/
public void initialize() {
// start a thread.
_thread = new PtolemyThread(this);
_isWaiting = true;
_thread.start();
}
/** Implement this method to define the job of the threaded actor.
*/
public abstract void run();
/** Clear input ports then wait until
* input events arrive.
*/
public void waitForNewInputs() {
_emptyPorts();
synchronized (_monitor) {
// Set the flag to true, so the director can wake up.
_isWaiting = true;
_monitor.notifyAll();
while (_isWaiting) {
try {
_monitor.wait();
} catch (InterruptedException e) {
System.err.println(KernelException.stackTraceToString(e));
}
}
}
}
/** Wait for new inputs on the specified array of ports.
* @param ports The array of ports whose inputs we're interested in.
* @exception IllegalActionException If the specified array of ports
* is not all input ports.
*/
public void waitForNewInputs(IOPort[] ports) throws IllegalActionException {
_emptyPorts();
while (true) {
waitForNewInputs();
// check for availability of tokens in the list of ports.
// If any of the listed ports has at least a token, then return
// Otherwise, wait for more new inputs.
for (int i = 0; i < ports.length; i++) {
IOPort port = ports[i];
for (int j = 0; j < port.getWidth(); j++) {
if (port.hasToken(j)) {
return;
}
}
}
} // while (true)
}
///////////////////////////////////////////////////////////////////
//// private methods ////
// Empty all receivers of all input ports.
// FIXME: Shouldn't this be guaranteed by the run() of the actor?
private void _emptyPorts() {
Iterator<?> ports = inputPortList().iterator();
while (ports.hasNext()) {
IOPort port = (IOPort) ports.next();
try {
for (int channel = 0; channel < port.getWidth(); channel++) {
try {
while (port.hasToken(channel)) {
port.get(channel);
}
} catch (IllegalActionException ex) {
throw new InternalErrorException(this, ex,
"Failed to empty ports?");
}
}
} catch (IllegalActionException ex) {
throw new InternalErrorException(
this,
ex,
"At this time IllegalActionExceptions are not allowed to happen.\n"
+ "Width inference should already have been done.");
}
}
}
///////////////////////////////////////////////////////////////////
//// private variables ////
private boolean _isWaiting = true;
private static Object _monitor = new Object();
private PtolemyThread _thread;
}