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.types.*;
31 import sun.jvm.hotspot.utilities.Observable;
32 import sun.jvm.hotspot.utilities.Observer;
33 
34 public class BasicObjectLock extends VMObject {
35   static {
36     VM.registerVMInitializedObserver(new Observer() {
37         public void update(Observable o, Object data) {
38           initialize(VM.getVM().getTypeDataBase());
39         }
40       });
41   }
42 
43   private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
44     Type type  = db.lookupType("BasicObjectLock");
45     objField   = type.getOopField("_obj");
46     size       = (int) type.getSize();
47   }
48 
49   private static sun.jvm.hotspot.types.OopField objField;
50   private static int        size;
51 
52   public BasicObjectLock(Address addr) {
53     super(addr);
54   }
55 
56   public OopHandle obj()  { return objField.getValue(addr); }
57 
58   /** Note: Use frame::interpreter_frame_monitor_size() for the size
59       of BasicObjectLocks in interpreter activation frames since it
60       includes machine-specific padding. This routine returns a size
61       in BYTES in this system! */
62   public static int size() { return size; }
63 
64   /** Helper routine for Frames (also probably needed for iteration) */
65   public Address address() { return addr; }
66 }