/* An actor that synchronizes tokens.
Copyright (c) 1997-2005 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
copyright notice and the following two paragraphs appear in all copies
of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
ENHANCEMENTS, OR MODIFICATIONS.
PT_COPYRIGHT_VERSION_2
COPYRIGHTENDKEY
*/
package ptolemy.actor.lib;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
//////////////////////////////////////////////////////////////////////////
//// Synchronizer
/**
This actor implements a token synchronizer. It has one input port and
one output port, both of which are multiports. When at least one token
exists on every input channel, exactly one token is consumed from each
input channel, and the tokens are output on the corresponding output
channels.
<p>
Note that the ordering of channels of a multiport is determined by the
order of connection. Thus the n<sup>th</sup> input channel connected
corresponds to the n<sup>th</sup> output channel connected.
@author Paul Whitaker
@version $Id$
@since Ptolemy II 1.0
@Pt.ProposedRating Yellow (pwhitake)
@Pt.AcceptedRating Yellow (pwhitake)
*/
public class Synchronizer extends Transformer {
/** Construct an actor in the specified container with the specified
* name.
* @param container The container.
* @param name The name of this actor within the container.
* @exception IllegalActionException If the actor cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the name coincides with
* an actor already in the container.
*/
public Synchronizer(CompositeEntity container, String name)
throws IllegalActionException, NameDuplicationException {
super(container, name);
input.setMultiport(true);
output.setMultiport(true);
}
///////////////////////////////////////////////////////////////////
//// public methods ////
/** Consume exactly one token from each input channel and output
* the tokens on the corresponding output channels.
* @exception IllegalActionException If there is no director or
* if the number of input channels does not equal the number of
* output channels.
*/
public void fire() throws IllegalActionException {
super.fire();
int outWidth = output.getWidth();
int inWidth = input.getWidth();
if (inWidth != outWidth) {
throw new IllegalActionException(this,
"Unequal synchronizer channels: " + inWidth
+ " inputs and " + outWidth + " outputs.");
} else {
for (int i = 0; i < inWidth; i++) {
output.send(i, input.get(i));
}
}
}
/** If all of the input channels have at least one token, return
* what the superclass returns (presumably true). Otherwise return
* false.
* @exception IllegalActionException If there is no director.
*/
public boolean prefire() throws IllegalActionException {
for (int i = 0; i < input.getWidth(); i++) {
if (!input.hasToken(i)) {
return false;
}
}
return super.prefire();
}
}