Mercurial > hg > Members > kono > jpf-core
view src/main/gov/nasa/jpf/util/event/EventChoiceGenerator.java @ 6:3a19eedcc13d
added a UniqueRandomPermGenerator that makes sure we don't return duplicates. It also checks the (unlikely and pointless) case that we request more permutations than N! and caps the number of samples accordingly
author | Peter Mehlitz <Peter.C.Mehlitz@nasa.gov> |
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date | Fri, 06 Feb 2015 10:12:12 -0800 |
parents | fdc263e5806b |
children | 8de43b2b023f |
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/* * Copyright (C) 2014, United States Government, as represented by the * Administrator of the National Aeronautics and Space Administration. * All rights reserved. * * The Java Pathfinder core (jpf-core) platform is licensed under the * Apache License, Version 2.0 (the "License"); you may not use this file except * in compliance with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0. * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package gov.nasa.jpf.util.event; import gov.nasa.jpf.util.Predicate; import gov.nasa.jpf.vm.ChoiceGeneratorBase; import gov.nasa.jpf.vm.SystemState; /** * ChoiceGenerator for Events. * This is basically just a pointer into the event tree */ public class EventChoiceGenerator extends ChoiceGeneratorBase<Event> { protected Event base; protected Event cur; protected int nProcessed; protected EventContext ctx; // optional, can replace/expand events during execution /** * convenience method to get successors from current CG chain */ public static EventChoiceGenerator getNext (SystemState ss, String id, Event base, EventContext ctx){ EventChoiceGenerator cgPrev = ss.getLastChoiceGeneratorOfType(EventChoiceGenerator.class); if (cgPrev == null){ return new EventChoiceGenerator( id, base, ctx); } else { return cgPrev.getSuccessor(id, ctx); } } public EventChoiceGenerator (String id, Event base){ this(id, base, null); } public EventChoiceGenerator (String id, Event base, EventContext ctx) { super(id); this.base = base; this.ctx = ctx; } @Override public Event getChoice (int idx){ if (idx >= 0){ Event e = base; for (int i=0; i<idx; i++){ e = e.alt; if (e == null){ break; } else { return e; } } } throw new IllegalArgumentException("choice index out of range: " + idx); } public void setContextExpander (EventContext ctx){ this.ctx = ctx; } public boolean containsMatchingChoice (Predicate<Event> predicate){ for (Event e = base; e != null; e = e.getAlt()){ if (predicate.isTrue(e)){ return true; } } return false; } public void addChoice (Event newEvent){ for (Event e = base; e != null;){ Event eAlt = e.getAlt(); if (eAlt == null){ e.setAlt(newEvent); return; } e = eAlt; } } public EventChoiceGenerator getSuccessor (String id){ return getSuccessor(id, null); } public EventChoiceGenerator getSuccessor (String id, EventContext ctx){ if (cur == null){ return new EventChoiceGenerator(id, base.getNext(), ctx); } else { Event next = cur.getNext(); if (cur instanceof CheckEvent){ // CheckEvents use next for conjunction while (next instanceof CheckEvent){ next = next.getNext(); } } if (next != null){ return new EventChoiceGenerator( id, next, ctx); } else { return null; // done } } } @Override public Event getNextChoice () { return cur; } @Override public boolean hasMoreChoices () { if (cur == null){ return (nProcessed == 0); } else { return (cur.getAlt() != null); } } @Override public void advance () { if (cur == null){ if (nProcessed == 0){ cur = base; nProcessed = 1; } } else { cur = cur.getAlt(); nProcessed++; } if (ctx != null){ Event newCur = ctx.map(cur); if (newCur != cur){ cur = newCur; } } } @Override public void reset () { isDone = false; cur = null; nProcessed = 0; } @Override public int getTotalNumberOfChoices () { return base.getNumberOfAlternatives(); } @Override public int getProcessedNumberOfChoices () { return nProcessed; } @Override public String toString() { StringBuilder sb = new StringBuilder(getClass().getName()); sb.append("{id:\""); sb.append(id); sb.append('"'); //sb.append(",isCascaded:"); //sb.append(Boolean.toString(isCascaded)); sb.append(",["); for (Event e=base; e!= null; e = e.getAlt()){ if (e != base){ sb.append(','); } if (e == cur){ sb.append(MARKER); } sb.append(e.toString()); } sb.append("],cur:"); sb.append(cur); sb.append("}"); return sb.toString(); } @Override public Class<Event> getChoiceType() { return Event.class; } }