/* An interface for actors that can remembers their state and go back to the state that is remembered. Copyright (c) 1998-2005 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.domains.ct.kernel; import ptolemy.actor.Actor; import ptolemy.kernel.util.IllegalActionException; ////////////////////////////////////////////////////////////////////////// //// CTStatefulActor /** Interface for actors that have states. The state of the actor can be marked (saved). The saved state can be restored so that an actor can go back to its previously marked state. This feature is used for rolling back the simulation when needed, which is essential when embedding CT subsystem in a discrete event system. <P> The interface defines two methods, markState() and goToMarkedState(). If the markState() method is called, the current state of the actor, for example values of the local variables, should be remembered. When the goToMarkedState() method is called after that, the marked states should be restored. @author Jie Liu @version $Id$ @since Ptolemy II 0.2 @Pt.ProposedRating Green (liuj) @Pt.AcceptedRating Green (yuhong) */ public interface CTStatefulActor extends Actor { /** Implementations of this method should go to the marked state. * If there's no marked state, throws an exception. * @exception IllegalActionException If there were no marked state. */ public void goToMarkedState() throws IllegalActionException; /** Implementations of this method should mark the current state * of the actor. */ public void markState(); }