1/*
2 * Copyright (c) 2000, 2017, 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.io.*;
28import java.util.*;
29import sun.jvm.hotspot.debugger.*;
30import sun.jvm.hotspot.runtime.*;
31import sun.jvm.hotspot.types.*;
32import sun.jvm.hotspot.utilities.*;
33
34//  ConstantPoolCache : A constant pool cache (ConstantPoolCache).
35//  See cpCache.hpp for details about this class.
36//
37public class ConstantPoolCache extends Metadata {
38  static {
39    VM.registerVMInitializedObserver(new Observer() {
40        public void update(Observable o, Object data) {
41          initialize(VM.getVM().getTypeDataBase());
42        }
43      });
44  }
45
46  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
47    Type type      = db.lookupType("ConstantPoolCache");
48    constants      = new MetadataField(type.getAddressField("_constant_pool"), 0);
49    baseOffset     = type.getSize();
50    Type elType    = db.lookupType("ConstantPoolCacheEntry");
51    elementSize    = elType.getSize();
52    length         = new CIntField(type.getCIntegerField("_length"), 0);
53    intSize        = VM.getVM().getObjectHeap().getIntSize();
54    resolvedReferences = type.getAddressField("_resolved_references");
55    referenceMap   = type.getAddressField("_reference_map");
56  }
57
58  public ConstantPoolCache(Address addr) {
59    super(addr);
60  }
61
62  public boolean isConstantPoolCache() { return true; }
63
64  private static MetadataField constants;
65
66  private static long baseOffset;
67  private static long elementSize;
68  private static CIntField length;
69  private static long intSize;
70  private static AddressField  resolvedReferences;
71  private static AddressField  referenceMap;
72
73  public ConstantPool getConstants() { return (ConstantPool) constants.getValue(this); }
74
75  public long getSize() {
76    return alignSize(baseOffset + getLength() * elementSize);
77  }
78
79  public ConstantPoolCacheEntry getEntryAt(int i) {
80    if (i < 0 || i >= getLength()) throw new IndexOutOfBoundsException(i + " " + getLength());
81    return new ConstantPoolCacheEntry(this, i);
82  }
83
84  public int getIntAt(int entry, int fld) {
85    long offset = baseOffset + entry * elementSize + fld * intSize;
86    return (int) getAddress().getCIntegerAt(offset, intSize, true );
87  }
88
89
90  public void printValueOn(PrintStream tty) {
91    tty.print("ConstantPoolCache for " + getConstants().getPoolHolder().getName().asString() + " address = " + getAddress() + " offset = " + baseOffset);
92  }
93
94  public int getLength() {
95    return (int) length.getValue(getAddress());
96  }
97
98  public void iterateFields(MetadataVisitor visitor) {
99    super.iterateFields(visitor);
100    visitor.doMetadata(constants, true);
101      for (int i = 0; i < getLength(); i++) {
102        ConstantPoolCacheEntry entry = getEntryAt(i);
103        entry.iterateFields(visitor);
104      }
105    }
106
107  public Oop getResolvedReferences() {
108    Address handle = resolvedReferences.getValue(getAddress());
109    if (handle != null) {
110      // Load through the handle
111      OopHandle refs = handle.getOopHandleAt(0);
112      return VM.getVM().getObjectHeap().newOop(refs);
113    }
114    return null;
115  }
116
117  public U2Array referenceMap() {
118    return new U2Array(referenceMap.getValue(getAddress()));
119  }
120};
121