KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > gov > nasa > jpf > search > heuristic > PreferThreads


1 //
2 // Copyright (C) 2005 United States Government as represented by the
3 // Administrator of the National Aeronautics and Space Administration
4 // (NASA). All Rights Reserved.
5 //
6 // This software is distributed under the NASA Open Source Agreement
7 // (NOSA), version 1.3. The NOSA has been approved by the Open Source
8 // Initiative. See the file NOSA-1.3-JPF at the top of the distribution
9 // 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.Config;
22 import gov.nasa.jpf.VM;
23 import gov.nasa.jpf.jvm.TrailInfo;
24
25
26 /**
27  * a heuristic state prioritizer that favors certain threads (specified
28  * by thread names during initialization)
29  *
30  * <2do> for both efficiency and encapsulation reasons, this should be just
31  * a Scheduler policy (so that we don't have to expand all children)
32  */
33 public class PreferThreads implements Heuristic {
34   VM vm;
35   String JavaDoc[] preferredThreads;
36
37   public PreferThreads (Config config, HeuristicSearch hSearch) {
38     vm = hSearch.getVM();
39     preferredThreads = config.getStringArray("search.heuristic.preferredThreads");
40   }
41
42   public int heuristicValue () {
43     TrailInfo t = (TrailInfo) vm.getLastTransition();
44
45     if (t == null) {
46       return 1;
47     }
48
49     String JavaDoc tn = vm.getThreadName();
50
51     for (int i = 0; i < preferredThreads.length; i++) {
52       if (tn.equals(preferredThreads[i])) {
53         return 0;
54       }
55     }
56
57     return 1;
58   }
59
60   public void processParent () {
61   }
62 }
63
Popular Tags