/*
@Copyright (c) 1998-2005 The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without
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software and its documentation for any purpose, provided that the
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*/
package ptolemy.domains.sdf.kernel.test;
import ptolemy.actor.TypedAtomicActor;
import ptolemy.actor.TypedIOPort;
import ptolemy.data.IntToken;
import ptolemy.data.expr.Parameter;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
/**
* This actor copies one token from its input to its output when fired.
*
* @author Steve Neuendorffer
* @version $Id$
* @since Ptolemy II 0.4
* @Pt.ProposedRating Red
* @Pt.AcceptedRating Red
*/
public class SDFTestDelay extends TypedAtomicActor {
/*
* Object constructor. This creates an object of class SDFTestDelay.
* The object will have a name given by the 'name' argument and will
* be contained within the composite actor given by the 'container'
* argument. This method throws two exceptions, which are error
* conditions that the method (or one of the methods it calls) has
* detected (notice the @exception tag).
*/
/**
* Create an SDFTestDelay actor in the given container with the given name.
* This actor copies one token from the input port named "input" to the
* output port named "output" when fired.
* @exception IllegalActionException If the contained methods throw it
* @exception NameDuplicationException If the contained methods throw it
*/
public SDFTestDelay(CompositeEntity container, String name)
throws IllegalActionException, NameDuplicationException {
/* This starts out by calling TypedAtomicActor's constructor.
* allows us to add some extra code specific to this actor, in
* addition to the regular initializer in TypedAtomicActor.
*/
super(container, name);
/* This construct is called a "try-catch block". It is used to
* detect exceptions that occurred during the execution of some
* other code. In this case, we detect IllegalActionException and
* print a reasonable error message. This is convenient under
* some environments which can destroy the debugging information from
* java
*/
/* Create a new input port */
input = new TypedIOPort(this, "input", true, false);
/* Set the Consumption rate on the port. A good way to think of
* this is that you are making a contract with the Ptolemy system.
* If you always consume one token from this port when fired,
* then Ptolemy will always guarantee that there will be a token
* ready when you are fired.
*/
input_tokenConsumptionRate = new Parameter(input,
"tokenConsumptionRate", new IntToken(1));
/* The getPort method (in ptolemy.kernel.Entity) finds a port by
* name. It returns a Port object, but all the ports in the
* actor package are of type TypedIOPort,
* which extends Port. So, we
* have to upcast the return value to the appropriate type.
* The setDeclaredType calls use the type system to define what
* types of tokens are valid for this actor.
*/
input.setTypeEquals(BaseType.INT);
/* Similarly for the output port */
output = new TypedIOPort(this, "output", false, true);
output_tokenProductionRate = new Parameter(output,
"tokenProductionRate", new IntToken(1));
output.setTypeEquals(BaseType.INT);
}
public TypedIOPort input;
public TypedIOPort output;
public Parameter input_tokenConsumptionRate;
public Parameter output_tokenProductionRate;
/* Notice that constructors start the file. Public methods should follow,
* in alphabetical order, followed by protected and private methods.
* Instance variables come at the end of the class.
*/
/* The fire method is where the bulk of the action takes place. In
* SDF, fire will be called exactly once between prefire and postfire.
* In this class, we get an input port, print its value, and put the
* same token back on the output port.
*/
/** This fires an actor and may be invoked several times between
* invocations of prefire() and postfire(). It may produce output
* data. Typically, the fire() method performs the computation associated
* with an actor.
*
* @exception IllegalActionException If firing is not permitted.
*/
public void fire() throws IllegalActionException {
/* First we declare a variable that is a Token that can carry
* integer data (ptolemy.data.IntToken).
*/
IntToken message;
/* Figure out how many tokens should be copied from the input to the
* output.
*/
int tokens = ((IntToken) input_tokenConsumptionRate.getToken())
.intValue();
if (((IntToken) output_tokenProductionRate.getToken()).intValue() != tokens) {
throw new IllegalActionException(
"SDFTestDelay: Rates on input port and output port "
+ "must match!");
}
int i;
for (i = 0; i < tokens; i++) {
/* now that we have the port, we can get a token from it.
* The argument to get is known as the channel.
* The channel must be
* zero, since there can only be one IORelation connected to this
* input. Multiple channels are useful with Multiports, which
* allow more than one relation to be connected to a port.
*/
message = (IntToken) input.get(0);
/* After looking at the token, pass it along to the next actor
*/
output.send(0, message);
}
}
/* Postfire is the last step in an iteration. This actor returns
* true, since it places no limit on how execution may proceed. In
* practice this method can be used to define a stopping condition,
* where execution will stop once some condition has been met.
*/
/** This method should be invoked once per iteration, after the last
* invocation of fire() in that iteration. It may produce output data.
* It returns true if the execution can proceed into the next iteration.
* This method typically wraps up an iteration, which may involve
* updating local state. In an opaque, non-atomic entity, it may also
* transfer output data.
*
* @return True if the execution can continue.
* @exception IllegalActionException If postfiring is not permitted.
*/
public boolean postfire() throws IllegalActionException {
return true;
}
/* Prefire is the first step in every iteration. This method returns
* true if the actor can perform useful work by being fired. For
* example, an actor could return false if it was waiting for a certain
* amount of data for a calculation, but that amount of data was not
* yet present. Most actors under SDF will just return true, since they
* have made a contract with the SDF domain to be fired when enough data
* is present.
*/
/** This method should be invoked once per iteration, before the first
* invocation of fire() in that iteration. It returns true if the
* iteration can proceed (the fire() method can be invoked). Thus
* this method will typically check preconditions for an iteration, if
* there are any. In an opaque, non-atomic entity,
* it may move data into an inner subsystem.
*
* @return True if the iteration can proceed.
* @exception IllegalActionException If prefiring is not permitted.
*/
public boolean prefire() throws IllegalActionException {
return true;
}
/* When this method is called, the actor must do everything in its power
* to immediately stop whatever it is doing. This is primarily
* called under
* two circumstances. The first is a user initiated break, such as
* via CTRL-C. The second is if an error occurs during wrapup() that
* cannot be recovered from.
*/
/** This method is invoked to immediately terminate any execution
* within an actor.
*/
public void terminate() {
return;
}
/* This method is called at the end of an execution, to allow the
* actor to cleanup after itself. Often this will involve destroying
* graphical windows, flushing buffers, etc. This method will also get
* called under most abnormal termination conditions.
* This actor has nothing to do here.
*/
/** This method should be invoked exactly once per execution
* of an application. None of the other action methods should be
* be invoked after it. It finalizes an execution, typically closing
* files, displaying final results, etc.
*
* @exception IllegalActionException If wrapup is not permitted.
*/
public void wrapup() throws IllegalActionException {
return;
}
}