| /* |
| * 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; |
| |
| /** |
| * |
| * @author Ken Cavanaugh |
| */ |
| public interface Guard |
| { |
| public static final class Complement extends GuardBase { |
| private Guard guard ; |
| |
| public Complement( GuardBase guard ) |
| { |
| super( "not(" + guard.getName() + ")" ) ; |
| this.guard = guard ; |
| } |
| |
| public Result evaluate( FSM fsm, Input in ) |
| { |
| return guard.evaluate( fsm, in ).complement() ; |
| } |
| } |
| |
| public static final class Result { |
| private String name ; |
| |
| private Result( String name ) |
| { |
| this.name = name ; |
| } |
| |
| public static Result convert( boolean res ) |
| { |
| return res ? ENABLED : DISABLED ; |
| } |
| |
| public Result complement() |
| { |
| if (this == ENABLED) |
| return DISABLED ; |
| else if (this == DISABLED) |
| return ENABLED ; |
| else |
| return DEFERED ; |
| } |
| |
| public String toString() |
| { |
| return "Guard.Result[" + name + "]" ; |
| } |
| |
| public static final Result ENABLED = new Result( "ENABLED" ) ; |
| public static final Result DISABLED = new Result( "DISABLED" ) ; |
| public static final Result DEFERED = new Result( "DEFERED" ) ; |
| } |
| |
| /** Called by the state engine to determine whether a |
| * transition is enabled, defered, or disabled. |
| * The result is interpreted as follows: |
| * <ul> |
| * <li>ENABLED if the transition is ready to proceed |
| * <li>DISABLED if the transition is not ready to proceed |
| * <li>DEFERED if the action associated with the transition |
| * is to be deferred. This means that the input will not be |
| * acted upon, but rather it will be saved for later execution. |
| * Typically this is implemented using a CondVar wait, and the |
| * blocked thread represents the defered input. The defered |
| * input is retried when the thread runs again. |
| * </ul> |
| * |
| * @param fsm is the state machine causing this action. |
| * @param in is the input that caused the transition. |
| */ |
| public Result evaluate( FSM fsm, Input in ) ; |
| } |
| |
| // end of Action.java |