Mercurial > jdk8-mips64-public > corba / annotate
src/share/classes/com/sun/corba/se/spi/orbutil/fsm/StateEngine.java@6845b95cba6b (annotated)
src/share/classes/com/sun/corba/se/spi/orbutil/fsm/StateEngine.java
Thu, 31 Aug 2017 18:10:36 +0800
- author
- aoqi
- date
- Thu, 31 Aug 2017 18:10:36 +0800
- changeset 748
- 6845b95cba6b
- parent 158
- 91006f157c46
- parent 0
- 7ef37b2cdcad
- permissions
- -rw-r--r--
merge
| aoqi@0 | 1 | /* |
| aoqi@0 | 2 | * Copyright (c) 2002, 2003, Oracle and/or its affiliates. All rights reserved. |
| aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| aoqi@0 | 4 | * |
| aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
| aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
| aoqi@0 | 7 | * published by the Free Software Foundation. Oracle designates this |
| aoqi@0 | 8 | * particular file as subject to the "Classpath" exception as provided |
| aoqi@0 | 9 | * by Oracle in the LICENSE file that accompanied this code. |
| aoqi@0 | 10 | * |
| aoqi@0 | 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| aoqi@0 | 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| aoqi@0 | 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| aoqi@0 | 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| aoqi@0 | 15 | * accompanied this code). |
| aoqi@0 | 16 | * |
| aoqi@0 | 17 | * You should have received a copy of the GNU General Public License version |
| aoqi@0 | 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| aoqi@0 | 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| aoqi@0 | 20 | * |
| aoqi@0 | 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| aoqi@0 | 22 | * or visit www.oracle.com if you need additional information or have any |
| aoqi@0 | 23 | * questions. |
| aoqi@0 | 24 | */ |
| aoqi@0 | 25 | |
| aoqi@0 | 26 | package com.sun.corba.se.spi.orbutil.fsm; |
| aoqi@0 | 27 | |
| aoqi@0 | 28 | /** |
| aoqi@0 | 29 | * A StateEngine defines the state transition function for a |
| aoqi@0 | 30 | * finite state machine (FSM). A FSM always has a current state. |
| aoqi@0 | 31 | * In response to an Input, the FSM performs an Action and |
| aoqi@0 | 32 | * makes a transition to a new state. Note that any object can |
| aoqi@0 | 33 | * be used as an input if it supports the Input interface. |
| aoqi@0 | 34 | * For example, a protocol message may be an input. The FSM |
| aoqi@0 | 35 | * uses only the result of calling getLabel on the Input to |
| aoqi@0 | 36 | * drive the transition. |
| aoqi@0 | 37 | * <p> |
| aoqi@0 | 38 | * The function can be non-deterministic |
| aoqi@0 | 39 | * in that the same input may cause transitions to different new |
| aoqi@0 | 40 | * states from the current state. In this case, the action that |
| aoqi@0 | 41 | * is executed for the transition must set the correct new state. |
| aoqi@0 | 42 | * |
| aoqi@0 | 43 | * @author Ken Cavanaugh |
| aoqi@0 | 44 | */ |
| aoqi@0 | 45 | public interface StateEngine |
| aoqi@0 | 46 | { |
| aoqi@0 | 47 | /** Add a new transition (old,in,guard,act,new) to the state engine. |
| aoqi@0 | 48 | * Multiple calls to add with the same old and in are permitted, |
| aoqi@0 | 49 | * in which case only a transition in which the guard evaluates to |
| aoqi@0 | 50 | * true will be taken. If no such transition is enabled, a default |
| aoqi@0 | 51 | * will be taken. If more than one transition is enabled, one will |
| aoqi@0 | 52 | * be chosen arbitrarily. |
| aoqi@0 | 53 | * This method can only be called before done(). An attempt to |
| aoqi@0 | 54 | * call it after done() results in an IllegalStateException. |
| aoqi@0 | 55 | */ |
| aoqi@0 | 56 | public StateEngine add( State oldState, Input input, Guard guard, |
| aoqi@0 | 57 | Action action, State newState ) throws IllegalStateException ; |
| aoqi@0 | 58 | |
| aoqi@0 | 59 | /** Add a transition with a guard that always evaluates to true. |
| aoqi@0 | 60 | */ |
| aoqi@0 | 61 | public StateEngine add( State oldState, Input input, |
| aoqi@0 | 62 | Action action, State newState ) throws IllegalStateException ; |
| aoqi@0 | 63 | |
| aoqi@0 | 64 | /** Set the default transition and action for a state. |
| aoqi@0 | 65 | * This transition will be used if no more specific transition was |
| aoqi@0 | 66 | * defined for the actual input. Repeated calls to this method |
| aoqi@0 | 67 | * simply change the default. |
| aoqi@0 | 68 | * This method can only be called before done(). An attempt to |
| aoqi@0 | 69 | * call it after done() results in an IllegalStateException. |
| aoqi@0 | 70 | */ |
| aoqi@0 | 71 | public StateEngine setDefault( State oldState, Action action, State newState ) |
| aoqi@0 | 72 | throws IllegalStateException ; |
| aoqi@0 | 73 | |
| aoqi@0 | 74 | /** Equivalent to setDefault( oldState, act, newState ) where act is an |
| aoqi@0 | 75 | * action that does nothing. |
| aoqi@0 | 76 | */ |
| aoqi@0 | 77 | public StateEngine setDefault( State oldState, State newState ) |
| aoqi@0 | 78 | throws IllegalStateException ; |
| aoqi@0 | 79 | |
| aoqi@0 | 80 | /** Euaivalent to setDefault( oldState, oldState ) |
| aoqi@0 | 81 | */ |
| aoqi@0 | 82 | public StateEngine setDefault( State oldState ) |
| aoqi@0 | 83 | throws IllegalStateException ; |
| aoqi@0 | 84 | |
| aoqi@0 | 85 | /** Set the default action used in this state engine. This is the |
| aoqi@0 | 86 | * action that is called whenever there is no applicable transition. |
| aoqi@0 | 87 | * Normally this would simply flag an error. This method can only |
| aoqi@0 | 88 | * be called before done(). An attempt to |
| aoqi@0 | 89 | * call it after done() results in an IllegalStateException. |
| aoqi@0 | 90 | */ |
| aoqi@0 | 91 | public void setDefaultAction( Action act ) throws IllegalStateException ; |
| aoqi@0 | 92 | |
| aoqi@0 | 93 | /** Called after all transitions have been added to the state engine. |
| aoqi@0 | 94 | * This provides an opportunity for the implementation to optimize |
| aoqi@0 | 95 | * its representation before the state engine is used. This method |
| aoqi@0 | 96 | * may only be called once. An attempt to call it more than once |
| aoqi@0 | 97 | * results in an IllegalStateException. |
| aoqi@0 | 98 | */ |
| aoqi@0 | 99 | public void done() throws IllegalStateException ; |
| aoqi@0 | 100 | |
| aoqi@0 | 101 | /** Create an instance of a FSM that uses this state engine. |
| aoqi@0 | 102 | * The initial state of the FSM will be the stateState specified |
| aoqi@0 | 103 | * here. This method can only be called after done(). An attempt |
| aoqi@0 | 104 | * to call it before done results in an IllegalStateException. |
| aoqi@0 | 105 | */ |
| aoqi@0 | 106 | public FSM makeFSM( State startState ) throws IllegalStateException ; |
| aoqi@0 | 107 | } |
| aoqi@0 | 108 | |
| aoqi@0 | 109 | // end of StateEngine.java |
