2 * Copyright (C) 2014, United States Government, as represented by the
3 * Administrator of the National Aeronautics and Space Administration.
6 * The Java Pathfinder core (jpf-core) platform is licensed under the
7 * Apache License, Version 2.0 (the "License"); you may not use this file except
8 * in compliance with the License. You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0.
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
18 package gov.nasa.jpf.search.heuristic;
20 import gov.nasa.jpf.Config;
21 import gov.nasa.jpf.vm.VM;
25 * heuristic state prioritizer that tries to minimize re-scheduling
27 public class GlobalSwitchThread extends SimplePriorityHeuristic {
28 private int[] threads;
30 public GlobalSwitchThread (Config config, VM vm) {
33 int threadHistorySize = config.getInt("search.heuristic.thread_history_size", 10);
35 threads = new int[threadHistorySize];
37 for (int i = 0; i < threads.length; i++) {
43 protected int computeHeuristicValue () {
44 int aliveThreads = vm.getThreadList().getMatchingCount(aliveThread);
46 int lastRun = vm.getLastTransition().getThreadIndex();
49 if (aliveThreads > 1) {
50 for (int i = 0; i < threads.length; i++) {
51 if (lastRun == threads[i]) {
52 h_value += ((threads.length - i) * aliveThreads);
57 int temp0 = threads[0];
61 for (int i = 1; i < threads.length; i++) {