1/*
2 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25package sun.jvm.hotspot.oops;
26
27import java.util.*;
28import sun.jvm.hotspot.debugger.*;
29import sun.jvm.hotspot.runtime.*;
30import sun.jvm.hotspot.types.*;
31import sun.jvm.hotspot.utilities.*;
32
33public class ConstantPoolCacheEntry {
34  private static long          size;
35  private static long          baseOffset;
36  private static CIntegerField indices;
37  private static AddressField  f1;
38  private static CIntegerField f2;
39  private static CIntegerField flags;
40
41  private ConstantPoolCache cp;
42  private long      offset;
43
44  static {
45    VM.registerVMInitializedObserver(new Observer() {
46        public void update(Observable o, Object data) {
47          initialize(VM.getVM().getTypeDataBase());
48        }
49      });
50  }
51
52  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
53    Type type      = db.lookupType("ConstantPoolCacheEntry");
54    size = type.getSize();
55
56    indices = type.getCIntegerField("_indices");
57    f1      = type.getAddressField ("_f1");
58    f2      = type.getCIntegerField("_f2");
59    flags   = type.getCIntegerField("_flags");
60
61    type = db.lookupType("ConstantPoolCache");
62    baseOffset = type.getSize();
63  }
64
65  ConstantPoolCacheEntry(ConstantPoolCache cp, int index) {
66    this.cp = cp;
67    offset  = baseOffset + index * size;
68  }
69
70  public int getConstantPoolIndex() {
71    if (Assert.ASSERTS_ENABLED) {
72      Assert.that((getIndices() & 0xFFFF) != 0, "must be main entry");
73    }
74    return (int) (getIndices() & 0xFFFF);
75  }
76
77  private long getIndices() {
78    return cp.getAddress().getCIntegerAt(indices.getOffset() + offset, indices.getSize(), indices.isUnsigned());
79  }
80
81  public Metadata getF1() {
82    return Metadata.instantiateWrapperFor(cp.getAddress().getAddressAt(f1.getOffset() + offset));
83  }
84
85  public int getF2() {
86    return cp.getAddress().getJIntAt(f1.getOffset() + offset);
87  }
88
89  public int getFlags() {
90    return cp.getAddress().getJIntAt(flags.getOffset() + offset);
91  }
92
93  static NamedFieldIdentifier f1FieldName = new NamedFieldIdentifier("_f1");
94  static NamedFieldIdentifier f2FieldName = new NamedFieldIdentifier("_f2");
95  static NamedFieldIdentifier flagsFieldName = new NamedFieldIdentifier("_flags");
96
97  public void iterateFields(MetadataVisitor visitor) {
98    visitor.doOop(new OopField(f1FieldName, f1.getOffset() + offset, true), true);
99    visitor.doInt(new IntField(f2FieldName, f2.getOffset() + offset, true), true);
100    visitor.doInt(new IntField(flagsFieldName, flags.getOffset() + offset, true), true);
101  }
102}
103