1 /*
2 * Copyright (c) 2000, 2020, 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
25 package sun.jvm.hotspot.oops;
26
27 import java.io.*;
28 import java.util.*;
29 import sun.jvm.hotspot.utilities.*;
30 import sun.jvm.hotspot.debugger.*;
31 import sun.jvm.hotspot.runtime.*;
32 import sun.jvm.hotspot.types.*;
33 import sun.jvm.hotspot.utilities.Observable;
34 import sun.jvm.hotspot.utilities.Observer;
35
36 // Oop represents the superclass for all types of
37 // objects in the HotSpot object heap.
38
39 public class Oop {
40 static {
41 VM.registerVMInitializedObserver(new Observer() {
42 public void update(Observable o, Object data) {
43 initialize(VM.getVM().getTypeDataBase());
44 }
45 });
46 }
47
48 private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
49 Type type = db.lookupType("oopDesc");
50 mark = new CIntField(type.getCIntegerField("_mark"), 0);
51 klass = new MetadataField(type.getAddressField("_metadata._klass"), 0);
52 compressedKlass = new NarrowKlassField(type.getAddressField("_metadata._compressed_klass"), 0);
53 headerSize = type.getSize();
54 }
55
56 private OopHandle handle;
57 private ObjectHeap heap;
58
59 Oop(OopHandle handle, ObjectHeap heap) {
60 this.handle = handle;
61 this.heap = heap;
62 }
63
64 ObjectHeap getHeap() { return heap; }
65
66 /** Should not be used or needed by most clients outside this
67 package; is needed, however, by {@link
68 sun.jvm.hotspot.utilities.MarkBits}. */
69 public OopHandle getHandle() { return handle; }
70
71 private static long headerSize;
72 public static long getHeaderSize() { return headerSize; } // Header size in bytes.
73
74 private static CIntField mark;
75 private static MetadataField klass;
76 private static NarrowKlassField compressedKlass;
77
78 // Accessors for declared fields
79 public Mark getMark() { return new Mark(getHandle()); }
80 public Klass getKlass() {
81 if (VM.getVM().isCompressedKlassPointersEnabled()) {
82 return (Klass)compressedKlass.getValue(getHandle());
83 } else {
84 return (Klass)klass.getValue(getHandle());
85 }
86 }
87
88 public boolean isA(Klass k) {
89 return getKlass().isSubtypeOf(k);
90 }
91
92 // Returns the byte size of this object
93 public long getObjectSize() {
94 Klass k = getKlass();
95 // All other types should be overriding getObjectSize directly
96 return ((InstanceKlass)k).getObjectSize(this);
97 }
98
99 // Type test operations
100 public boolean isInstance() { return false; }
101 public boolean isInstanceRef() { return false; }
102 public boolean isArray() { return false; }
103 public boolean isObjArray() { return false; }
104 public boolean isTypeArray() { return false; }
105 public boolean isThread() { return false; }
106
107 // Align the object size.
108 public static long alignObjectSize(long size) {
109 return VM.getVM().alignUp(size, VM.getVM().getMinObjAlignmentInBytes());
110 }
111
112 // All vm's align longs, so pad out certain offsets.
113 public static long alignObjectOffset(long offset) {
114 return VM.getVM().alignUp(offset, VM.getVM().getBytesPerLong());
115 }
116
117 public boolean equals(Object obj) {
118 if (obj != null && (obj instanceof Oop)) {
119 return getHandle().equals(((Oop) obj).getHandle());
120 }
121 return false;
122 }
123
124 public int hashCode() { return getHandle().hashCode(); }
125
126 /** Identity hash in the target VM */
127 public long identityHash() {
128 Mark mark = getMark();
129 if (mark.isUnlocked() && (!mark.hasNoHash())) {
130 return (int) mark.hash();
131 } else if (mark.isMarked()) {
132 return (int) mark.hash();
133 } else {
134 return slowIdentityHash();
135 }
136 }
137
138 public long slowIdentityHash() {
139 return VM.getVM().getObjectSynchronizer().identityHashValueFor(this);
140 }
141
142 public void iterate(OopVisitor visitor, boolean doVMFields) {
143 visitor.setObj(this);
144 visitor.prologue();
145 iterateFields(visitor, doVMFields);
146 visitor.epilogue();
147 }
148
149 void iterateFields(OopVisitor visitor, boolean doVMFields) {
150 if (doVMFields) {
151 visitor.doCInt(mark, true);
152 if (VM.getVM().isCompressedKlassPointersEnabled()) {
153 visitor.doMetadata(compressedKlass, true);
154 } else {
155 visitor.doMetadata(klass, true);
156 }
157 }
158 }
159
160 public void print() { printOn(System.out); }
161 public void printValue() { printValueOn(System.out); }
162 public void printRaw() { printRawOn(System.out); }
163
164 public static void printOopValueOn(Oop obj, PrintStream tty) {
165 if (obj == null) {
166 tty.print("null");
167 } else {
168 obj.printValueOn(tty);
169 tty.print(" @ " + VM.getVM().getUniverse().heap().oopAddressDescription(obj.getHandle()));
170 }
171 }
172
173 public static void printOopAddressOn(Oop obj, PrintStream tty) {
174 if (obj == null) {
175 tty.print("null");
176 } else {
177 tty.print(obj.getHandle().toString());
178 }
179 }
180
181 public void printOn(PrintStream tty) {
182 OopPrinter printer = new OopPrinter(tty);
183 iterate(printer, true);
184 }
185
186 public void printValueOn(PrintStream tty) {
187 try {
188 tty.print("Oop for " + getKlass().getName().asString());
189 } catch (java.lang.NullPointerException e) {
190 tty.print("Oop");
191 }
192 }
193
194 public void printRawOn(PrintStream tty) {
195 tty.print("Dumping raw memory for ");
196 printValueOn(tty);
197 tty.println();
198 long size = getObjectSize() * 4;
199 for (long i = 0; i < size; i += 4) {
200 long memVal = getHandle().getCIntegerAt(i, 4, true);
201 tty.println(Long.toHexString(memVal));
202 }
203 }
204
205 public boolean verify() { return true;}
206
207 public static Klass getKlassForOopHandle(OopHandle handle) {
208 if (handle == null) {
209 return null;
210 }
211 if (VM.getVM().isCompressedKlassPointersEnabled()) {
212 return (Klass)Metadata.instantiateWrapperFor(handle.getCompKlassAddressAt(compressedKlass.getOffset()));
213 } else {
214 return (Klass)Metadata.instantiateWrapperFor(handle.getAddressAt(klass.getOffset()));
215 }
216 }
217 };