1 /*
   2  * Copyright (c) 2002, 2003, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.corba.se.spi.orbutil.fsm ;
  27 
  28 /**
  29  * An FSM is used to represent an instance of a finite state machine
  30  * which has a transition function represented by an instance of
  31  * StateEngine.  An instance of an FSM may be created either by calling
  32  * StateEngine.makeFSM( startState ) on a state engine, or by extending FSMImpl and
  33  * using a constructor.  Using FSMImpl as a base class is convenient if
  34  * additional state is associated with the FSM beyond that encoded
  35  * by the current state.  This is especially convenient if an action
  36  * needs some additional information.  For example, counters are best
  37  * handled by special actions rather than encoding a bounded counter
  38  * in a state machine.  It is also possible to create a class that
  39  * implements the FSM interface by delegating to an FSM instance
  40  * created by StateEngine.makeFSM.
  41  *
  42  * @author Ken Cavanaugh
  43  */
  44 public interface FSM
  45 {
  46     /** Get the current state of this FSM.
  47     */
  48     public State getState() ;
  49 
  50     /** Perform the action and transition to the next state based
  51     * on the current state of the FSM and the input.
  52     */
  53     public void doIt( Input in ) ;
  54 }
  55 
  56 // end of FSM.java