//
// Copyright (C) 2006 United States Government as represented by the
// Administrator of the National Aeronautics and Space Administration
// (NASA). All Rights Reserved.
//
// This software is distributed under the NASA Open Source Agreement
// (NOSA), version 1.3. The NOSA has been approved by the Open Source
// Initiative. See the file NOSA-1.3-JPF at the top of the distribution
// directory tree for the complete NOSA document.
//
// THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
// KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
// LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
// SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
// A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
// THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
// DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
//
package gov.nasa.jpf.search.heuristic;
import gov.nasa.jpf.Config;
import gov.nasa.jpf.vm.VM;
/**
* Heuristic state prioriizer that maximizes number of blocked states. This
* is a classic heuristic for finding deadlocks, since a deadlock requires
* all threads to be blocked.
*/
public class MostBlocked extends SimplePriorityHeuristic {
public MostBlocked (Config config, VM vm) {
super(config,vm);
}
protected int computeHeuristicValue () {
int alive = vm.getThreadList().getMatchingCount(aliveThread);
int runnable = vm.getThreadList().getMatchingCount(vm.getTimedoutRunnablePredicate());
// pcm - the (iSystemState based) condition was "!runnable && alive"
// the '10000' is just a potential max thread count
int h_value = (10000 - (alive - runnable));
return h_value;
}
}