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 if (VM.getVM().isCompactObjectHeadersEnabled()) {
52 Type markType = db.lookupType("markWord");
53 headerSize = markType.getSize();
54 } else {
55 headerSize = type.getSize();
56 klass = new MetadataField(type.getAddressField("_metadata._klass"), 0);
57 compressedKlass = new NarrowKlassField(type.getAddressField("_metadata._compressed_klass"), 0);
58 }
59 }
60
61 private OopHandle handle;
62 private ObjectHeap heap;
63
64 Oop(OopHandle handle, ObjectHeap heap) {
65 this.handle = handle;
66 this.heap = heap;
67 }
68
69 ObjectHeap getHeap() { return heap; }
70
71 /** Should not be used or needed by most clients outside this
72 package; is needed, however, by {@link
73 sun.jvm.hotspot.utilities.MarkBits}. */
74 public OopHandle getHandle() { return handle; }
75
76 private static long headerSize;
77 public static long getHeaderSize() { return headerSize; } // Header size in bytes.
78
79 private static CIntField mark;
80 private static MetadataField klass;
81 private static NarrowKlassField compressedKlass;
82
83 // Accessors for declared fields
84 public Mark getMark() { return new Mark(getHandle()); }
85
86 private static Klass getKlass(Mark mark) {
87 assert(VM.getVM().isCompactObjectHeadersEnabled());
88 if (mark.hasMonitor()) {
89 ObjectMonitor mon = mark.monitor();
90 mark = mon.header();
91 }
92 return mark.getKlass();
93 }
94
95 public Klass getKlass() {
96 if (VM.getVM().isCompactObjectHeadersEnabled()) {
97 assert(VM.getVM().isCompressedKlassPointersEnabled());
98 return getKlass(getMark());
99 } else if (VM.getVM().isCompressedKlassPointersEnabled()) {
100 return (Klass)compressedKlass.getValue(getHandle());
101 } else {
102 return (Klass)klass.getValue(getHandle());
103 }
104 }
105
106 public boolean isA(Klass k) {
107 return getKlass().isSubtypeOf(k);
108 }
109
110 // Returns the byte size of this object
111 public long getObjectSize() {
112 Klass k = getKlass();
113 // All other types should be overriding getObjectSize directly
114 return ((InstanceKlass)k).getObjectSize(this);
115 }
116
117 // Type test operations
118 public boolean isInstance() { return false; }
119 public boolean isInstanceRef() { return false; }
120 public boolean isArray() { return false; }
121 public boolean isObjArray() { return false; }
122 public boolean isTypeArray() { return false; }
123 public boolean isThread() { return false; }
124
125 // Align the object size.
126 public static long alignObjectSize(long size) {
127 return VM.getVM().alignUp(size, VM.getVM().getMinObjAlignmentInBytes());
128 }
129
130 // All vm's align longs, so pad out certain offsets.
131 public static long alignObjectOffset(long offset) {
132 return VM.getVM().alignUp(offset, VM.getVM().getBytesPerLong());
133 }
134
135 public boolean equals(Object obj) {
136 if (obj != null && (obj instanceof Oop)) {
137 return getHandle().equals(((Oop) obj).getHandle());
138 }
139 return false;
140 }
141
142 public int hashCode() { return getHandle().hashCode(); }
143
144 /** Identity hash in the target VM */
145 public long identityHash() {
146 Mark mark = getMark();
147 if (mark.isUnlocked() && (!mark.hasNoHash())) {
148 return (int) mark.hash();
149 } else if (mark.isMarked()) {
150 return (int) mark.hash();
151 } else {
152 return slowIdentityHash();
153 }
154 }
155
156 public long slowIdentityHash() {
157 return VM.getVM().getObjectSynchronizer().identityHashValueFor(this);
158 }
159
160 public void iterate(OopVisitor visitor, boolean doVMFields) {
161 visitor.setObj(this);
162 visitor.prologue();
163 iterateFields(visitor, doVMFields);
164 visitor.epilogue();
165 }
166
167 void iterateFields(OopVisitor visitor, boolean doVMFields) {
168 if (doVMFields) {
169 visitor.doCInt(mark, true);
170 if (!VM.getVM().isCompactObjectHeadersEnabled()) {
171 if (VM.getVM().isCompressedKlassPointersEnabled()) {
172 visitor.doMetadata(compressedKlass, true);
173 } else {
174 visitor.doMetadata(klass, true);
175 }
176 }
177 }
178 }
179
180 public void print() { printOn(System.out); }
181 public void printValue() { printValueOn(System.out); }
182 public void printRaw() { printRawOn(System.out); }
183
184 public static void printOopValueOn(Oop obj, PrintStream tty) {
185 if (obj == null) {
186 tty.print("null");
187 } else {
188 obj.printValueOn(tty);
189 tty.print(" @ " + VM.getVM().getUniverse().heap().oopAddressDescription(obj.getHandle()));
190 }
191 }
192
193 public static void printOopAddressOn(Oop obj, PrintStream tty) {
194 if (obj == null) {
195 tty.print("null");
196 } else {
197 tty.print(obj.getHandle().toString());
198 }
199 }
200
201 public void printOn(PrintStream tty) {
202 OopPrinter printer = new OopPrinter(tty);
203 iterate(printer, true);
204 }
205
206 public void printValueOn(PrintStream tty) {
207 try {
208 tty.print("Oop for " + getKlass().getName().asString());
209 } catch (java.lang.NullPointerException e) {
210 tty.print("Oop");
211 }
212 }
213
214 public void printRawOn(PrintStream tty) {
215 tty.print("Dumping raw memory for ");
216 printValueOn(tty);
217 tty.println();
218 long size = getObjectSize() * 4;
219 for (long i = 0; i < size; i += 4) {
220 long memVal = getHandle().getCIntegerAt(i, 4, true);
221 tty.println(Long.toHexString(memVal));
222 }
223 }
224
225 public boolean verify() { return true;}
226
227 public static Klass getKlassForOopHandle(OopHandle handle) {
228 if (handle == null) {
229 return null;
230 }
231 if (VM.getVM().isCompactObjectHeadersEnabled()) {
232 Mark mark = new Mark(handle);
233 return getKlass(mark);
234 } else if (VM.getVM().isCompressedKlassPointersEnabled()) {
235 return (Klass)Metadata.instantiateWrapperFor(handle.getCompKlassAddressAt(compressedKlass.getOffset()));
236 } else {
237 return (Klass)Metadata.instantiateWrapperFor(handle.getAddressAt(klass.getOffset()));
238 }
239 }
240 };