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Java > Open Source Codes > gov > nasa > jpf > jvm > Labels


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.jvm;
20
21 import gov.nasa.jpf.jvm.bytecode.Instruction;
22 import gov.nasa.jpf.util.Debug;
23
24 import java.util.Hashtable JavaDoc;
25
26
27 /**
28  * helper class to tag certain execution states
29  */
30 public class Labels {
31   private static Hashtable JavaDoc labels = new Hashtable JavaDoc();
32
33   public static boolean isAt (String JavaDoc label, ThreadInfo th) {
34     Instruction pc = (Instruction) labels.get(label);
35
36     if (pc == null) {
37       return false;
38     }
39
40     return th.getPC() == pc;
41   }
42
43   public static void set (String JavaDoc label, Instruction pc) {
44     if (!JVM.observableLabels.contains(label)) {
45       Debug.println(Debug.MESSAGE, "Ignored label: " + label);
46
47       return;
48     }
49
50     if (labels.containsKey(label)) {
51       return;
52     }
53
54     labels.put(label, pc);
55     pc.setObservable();
56     Debug.println(Debug.MESSAGE, "New label: " + label);
57   }
58 }
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