1 /*
2 * Copyright (c) 2001, 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.runtime;
26
27 import java.util.*;
28
29 import sun.jvm.hotspot.debugger.*;
30 import sun.jvm.hotspot.oops.*;
31 import sun.jvm.hotspot.types.*;
32 import sun.jvm.hotspot.utilities.Observable;
33 import sun.jvm.hotspot.utilities.Observer;
34
35 public class BasicLock extends VMObject {
36 static {
37 VM.registerVMInitializedObserver(new Observer() {
38 public void update(Observable o, Object data) {
39 initialize(VM.getVM().getTypeDataBase());
40 }
41 });
42 }
43
44 private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
45 Type type = db.lookupType("BasicLock");
46 displacedHeaderField = type.getCIntegerField("_metadata");
47 }
48
49 private static CIntegerField displacedHeaderField;
50
51 public BasicLock(Address addr) {
52 super(addr);
53 }
54
55 public Mark displacedHeader() {
56 return new Mark(addr.addOffsetTo(displacedHeaderField.getOffset()));
57 }
58 }