Mercurial > hg > Members > kono > jpf-core
view src/main/gov/nasa/jpf/search/heuristic/GlobalSwitchThread.java @ 0:61d41facf527
initial v8 import (history reset)
author | Peter Mehlitz <Peter.C.Mehlitz@nasa.gov> |
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date | Fri, 23 Jan 2015 10:14:01 -0800 |
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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.search.heuristic; import gov.nasa.jpf.Config; import gov.nasa.jpf.vm.VM; /** * heuristic state prioritizer that tries to minimize re-scheduling */ public class GlobalSwitchThread extends SimplePriorityHeuristic { private int[] threads; public GlobalSwitchThread (Config config, VM vm) { super(config, vm); int threadHistorySize = config.getInt("search.heuristic.thread_history_size", 10); threads = new int[threadHistorySize]; for (int i = 0; i < threads.length; i++) { threads[i] = -1; } } @Override protected int computeHeuristicValue () { int aliveThreads = vm.getThreadList().getMatchingCount(aliveThread); int lastRun = vm.getLastTransition().getThreadIndex(); int h_value = 0; if (aliveThreads > 1) { for (int i = 0; i < threads.length; i++) { if (lastRun == threads[i]) { h_value += ((threads.length - i) * aliveThreads); } } } int temp0 = threads[0]; int temp1; threads[0] = lastRun; for (int i = 1; i < threads.length; i++) { temp1 = threads[i]; threads[i] = temp0; temp0 = temp1; } return h_value; } }