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.jvm.bytecode;
20:
21: import gov.nasa.jpf.jvm.ArrayIndexOutOfBoundsExecutiveException;
22: import gov.nasa.jpf.jvm.ElementInfo;
23: import gov.nasa.jpf.jvm.KernelState;
24: import gov.nasa.jpf.jvm.SystemState;
25: import gov.nasa.jpf.jvm.ThreadInfo;
26:
27: /**
28: *abstraction for all array load instructions
29: */
30: public abstract class ArrayLoadInstruction extends ArrayInstruction {
31: public Instruction execute(SystemState ss, KernelState ks,
32: ThreadInfo th) {
33: int index;
34: int arrayRef;
35: ElementInfo e;
36:
37: index = th.pop();
38: arrayRef = th.pop();
39:
40: if (arrayRef == -1) {
41: return th
42: .createAndThrowException("java.lang.NullPointerException");
43: }
44:
45: e = ks.da.get(arrayRef);
46:
47: try {
48: push(th, e, index);
49:
50: return getNext(th);
51: } catch (ArrayIndexOutOfBoundsExecutiveException ex) {
52: return ex.getInstruction();
53: }
54: }
55:
56: protected boolean isReference() {
57: return false;
58: }
59:
60: protected void push(ThreadInfo th, ElementInfo e, int index)
61: throws ArrayIndexOutOfBoundsExecutiveException {
62: e.checkArrayBounds(index);
63: th.push(e.getElement(index), isReference());
64: }
65:
66: public boolean isSchedulingRelevant(SystemState ss, KernelState ks,
67: ThreadInfo ti) {
68: // should be further discriminated based on if the array object
69: // is reachable for multiple threads
70: if (ti.usePorFieldBoundaries()) {
71: if (ks.da.isSchedulingRelevantObject(ti.peek(1))
72: && ti.hasOtherRunnables()) {
73: return true;
74: }
75: }
76:
77: return false;
78: }
79: }
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