01: //
02: // Copyright (C) 2005 United States Government as represented by the
03: // Administrator of the National Aeronautics and Space Administration
04: // (NASA). All Rights Reserved.
05: //
06: // This software is distributed under the NASA Open Source Agreement
07: // (NOSA), version 1.3. The NOSA has been approved by the Open Source
08: // Initiative. See the file NOSA-1.3-JPF at the top of the distribution
09: // directory tree for the complete NOSA document.
10: //
11: // THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
12: // KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
13: // LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
14: // SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
15: // A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
16: // THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
17: // DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
18: //
19: package gov.nasa.jpf.search.heuristic;
20:
21: import gov.nasa.jpf.VM;
22:
23: /**
24: * heuristic state prioritizer that favors search depth
25: */
26: public class DFSHeuristic implements Heuristic {
27: VM vm;
28: HeuristicSearch hSearch;
29:
30: public DFSHeuristic(HeuristicSearch hs) {
31: hSearch = hs;
32: vm = hSearch.getVM();
33: }
34:
35: public int heuristicValue() {
36: // <2do> pcm - is that correct if the search depth is not limited (-1) ?
37: return hSearch.getDepthLimit() - vm.getPathLength();
38: }
39:
40: public void processParent() {
41: }
42: }
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