| /* |
| * Copyright (c) 2002, 2003, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.corba.se.spi.orbutil.fsm ; |
| |
| import java.util.Set ; |
| import java.util.HashSet ; |
| |
| import com.sun.corba.se.spi.orbutil.fsm.Input ; |
| import com.sun.corba.se.spi.orbutil.fsm.StateEngine ; |
| import com.sun.corba.se.impl.orbutil.fsm.StateEngineImpl ; |
| import com.sun.corba.se.impl.orbutil.ORBUtility ; |
| import com.sun.corba.se.spi.orbutil.fsm.FSM ; |
| |
| /** |
| * This is the main class that represents an instance of a state machine |
| * using a state engine. It may be used as a base class, in which case |
| * the guards and actions have access to the derived class. |
| * |
| * @author Ken Cavanaugh |
| */ |
| public class FSMImpl implements FSM |
| { |
| private boolean debug ; |
| private State state ; |
| private StateEngineImpl stateEngine ; |
| |
| /** Create an instance of an FSM using the StateEngine |
| * in a particular start state. |
| */ |
| public FSMImpl( StateEngine se, State startState ) |
| { |
| this( se, startState, false ) ; |
| } |
| |
| public FSMImpl( StateEngine se, State startState, boolean debug ) |
| { |
| state = startState ; |
| stateEngine = (StateEngineImpl)se ; |
| this.debug = debug ; |
| } |
| |
| /** Return the current state. |
| */ |
| public State getState() |
| { |
| return state ; |
| } |
| |
| /** Perform the transition for the given input in the current state. This proceeds as follows: |
| * <p>Let S be the current state of the FSM. |
| * If there are guarded actions for S with input in, evaluate their guards successively until |
| * all have been evaluted, or one returns a non-DISABLED Result. |
| * <ol> |
| * <li>If a DEFERED result is returned, retry the input |
| * <li>If a ENABLED result is returned, the action for the guarded action |
| * is the current action |
| * <li>Otherwise there is no enabled action. If S has a default action and next state, use them; otherwise |
| * use the state engine default action (the next state is always the current state). |
| * </ol> |
| * After the action is available, the transition proceeds as follows: |
| * <ol> |
| * <li>If the next state is not the current state, execute the current state postAction method. |
| * <li>Execute the action. |
| * <li>If the next state is not the current state, execute the next state preAction method. |
| * <li>Set the current state to the next state. |
| * </ol> |
| */ |
| public void doIt( Input in ) |
| { |
| stateEngine.doIt( this, in, debug ) ; |
| } |
| |
| // Methods for use only by StateEngineImpl |
| |
| public void internalSetState( State nextState ) |
| { |
| if (debug) { |
| ORBUtility.dprint( this, "Calling internalSetState with nextState = " + |
| nextState ) ; |
| } |
| |
| state = nextState ; |
| |
| if (debug) { |
| ORBUtility.dprint( this, "Exiting internalSetState with state = " + |
| state ) ; |
| } |
| } |
| } |
| |
| // end of FSMImpl.java |