001/* An actor that delays the input for a certain amount of real time.
002
003 Copyright (c) 1998-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026
027 */
028package ptolemy.actor.lib;
029
030import ptolemy.actor.TypedIOPort;
031import ptolemy.data.LongToken;
032import ptolemy.data.Token;
033import ptolemy.data.expr.Parameter;
034import ptolemy.data.type.BaseType;
035import ptolemy.kernel.CompositeEntity;
036import ptolemy.kernel.util.IllegalActionException;
037import ptolemy.kernel.util.NameDuplicationException;
038
039///////////////////////////////////////////////////////////////////
040//// Sleep
041
042/**
043 An actor that calls Thread.sleep() on the current thread the first
044 time fire() is called.  The sleep delays the inputs for a certain
045 amount of real time, specified by the <i>sleepTime</i> input.
046
047 <p>Note that one way to slow down the execution of a model while running
048 inside vergil is to turn on animation.
049
050 <p>If the width of the output port is less than that of the input port,
051 the tokens in the extra channels are lost.
052
053 @author Yang Zhao, based on Sleep by Jie Liu, Christopher Hylands
054 @version $Id$
055 @since Ptolemy II 1.0
056 @Pt.ProposedRating Yellow (cxh)
057 @Pt.AcceptedRating Yellow (cxh)
058 */
059public class VariableSleep extends Transformer {
060    /** Construct an actor with the given container and name.
061     *  @param container The container.
062     *  @param name The name of this actor.
063     *  @exception IllegalActionException If the actor cannot be contained
064     *   by the proposed container.
065     *  @exception NameDuplicationException If the container already has an
066     *   actor with this name.
067     */
068    public VariableSleep(CompositeEntity container, String name)
069            throws NameDuplicationException, IllegalActionException {
070        super(container, name);
071        defaultSleepTime = new Parameter(this, "defaultSleepTime",
072                new LongToken(0));
073        defaultSleepTime.setTypeEquals(BaseType.LONG);
074
075        // Data type polymorphic, multiports.
076        input.setMultiport(true);
077        output.setMultiport(true);
078        sleepTime = new TypedIOPort(this, "sleepTime", true, false);
079        sleepTime.setTypeEquals(BaseType.LONG);
080    }
081
082    ///////////////////////////////////////////////////////////////////
083    ////                     ports and parameters                  ////
084
085    /** The sleepTime amount, in milliseconds
086     *  This parameter must contain a LongToken.
087     *  The default value of this parameter is 0, meaning
088     *  that this actor will not sleep the current thread at all.
089     */
090    public Parameter defaultSleepTime;
091
092    /** An input port receives the value of sleep time.
093     */
094    public TypedIOPort sleepTime;
095
096    ///////////////////////////////////////////////////////////////////
097    ////                         public methods                    ////
098
099    /** Call Thread.sleep() the first time fire is called and then
100     *  transfer tokens from inputs to outputs, one token from each
101     *  channel.  If fire() is called twice in a row without an
102     *  intervening call to either postfire() or prefire(), then no
103     *  output is produced.
104     *  <p>If the width of the output port is less than
105     *  that of the input port, the tokens in the extra channels
106     *  are lost.
107     *  @exception IllegalActionException Not thrown in this base class */
108    @Override
109    public void fire() throws IllegalActionException {
110        super.fire();
111        if (!_wasSleepCalledInFireYet) {
112            try {
113                if (sleepTime.hasToken(0)) {
114                    _sleepTime = ((LongToken) sleepTime.get(0)).longValue();
115                } else {
116                    _sleepTime = ((LongToken) defaultSleepTime.getToken())
117                            .longValue();
118                }
119
120                if (_debugging) {
121                    _debug(getName() + ": Wait for " + _sleepTime
122                            + " milliseconds.");
123                }
124
125                Thread.sleep(_sleepTime);
126            } catch (InterruptedException e) {
127                // Ignore...
128            }
129
130            // Pull these out of the loop so we do not call them
131            // more than once.
132            int inputWidth = input.getWidth();
133            int outputWidth = output.getWidth();
134
135            for (int i = 0; i < inputWidth; i++) {
136                if (input.hasToken(i)) {
137                    Token inToken = input.get(i);
138
139                    if (i < outputWidth) {
140                        output.send(i, inToken);
141                    }
142                }
143            }
144        }
145    }
146
147    /** Reset the flag that fire() checks so that fire() only sleeps once.
148     *  @exception IllegalActionException If the parent class throws it.
149     *  @return Whatever the superclass returns (probably true).
150     */
151    @Override
152    public boolean postfire() throws IllegalActionException {
153        _wasSleepCalledInFireYet = false;
154        return super.postfire();
155    }
156
157    /** Reset the flag that fire() checks so that fire() only sleeps once.
158     *  @exception IllegalActionException If the parent class throws it.
159     *  @return Whatever the superclass returns (probably true).
160     */
161    @Override
162    public boolean prefire() throws IllegalActionException {
163        _wasSleepCalledInFireYet = false;
164        return super.prefire();
165    }
166
167    ///////////////////////////////////////////////////////////////////
168    ////                         private variables                 ////
169    // True if sleep was called in fire().  Sleep should only
170    // be called once in fire().
171    private boolean _wasSleepCalledInFireYet = false;
172
173    private long _sleepTime;
174}