1 /*
2 * Copyright (c) 2001, 2021, 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 ObjectMonitor 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 heap = VM.getVM().getObjectHeap();
46 Type type = db.lookupType("ObjectMonitor");
47
48 sun.jvm.hotspot.types.Field f = type.getField("_metadata");
49 metadataFieldOffset = f.getOffset();
50 f = type.getField("_object");
51 objectFieldOffset = f.getOffset();
52 f = type.getField("_owner");
53 ownerFieldOffset = f.getOffset();
54 f = type.getField("_next_om");
55 nextOMFieldOffset = f.getOffset();
56 contentionsField = new CIntField(type.getCIntegerField("_contentions"), 0);
57 waitersField = new CIntField(type.getCIntegerField("_waiters"), 0);
58 recursionsField = type.getCIntegerField("_recursions");
59
60 ANONYMOUS_OWNER = db.lookupLongConstant("ObjectMonitor::ANONYMOUS_OWNER").longValue();
61 }
62
63 public ObjectMonitor(Address addr) {
64 super(addr);
65 }
66
67 public Mark header() {
68 return new Mark(addr.addOffsetTo(metadataFieldOffset));
69 }
70
71 // FIXME
72 // void set_header(markWord hdr);
73
74 // FIXME: must implement and delegate to platform-dependent implementation
75 // public boolean isBusy();
76 public boolean isEntered(sun.jvm.hotspot.runtime.Thread current) {
77 Address o = owner();
78 if (current.threadObjectAddress().equals(o) ||
79 current.isLockOwned(o)) {
80 return true;
81 }
82 return false;
83 }
84
85 public boolean isOwnedAnonymous() {
86 return addr.getAddressAt(ownerFieldOffset).asLongValue() == ANONYMOUS_OWNER;
87 }
88
89 public Address owner() { return addr.getAddressAt(ownerFieldOffset); }
90 // FIXME
91 // void set_owner(void* owner);
92
93 public int waiters() { return (int)waitersField.getValue(this); }
94
95 public Address nextOM() { return addr.getAddressAt(nextOMFieldOffset); }
96 // FIXME
97 // void set_queue(void* owner);
98
99 public long recursions() { return recursionsField.getValue(addr); }
100
101 public OopHandle object() {
102 Address objAddr = addr.getAddressAt(objectFieldOffset);
103 if (objAddr == null) {
104 return null;
105 }
106 return objAddr.getOopHandleAt(0);
107 }
108
109 public int contentions() {
110 return (int)contentionsField.getValue(this);
111 }
112
113 // The following four either aren't expressed as typed fields in
114 // vmStructs.cpp because they aren't strongly typed in the VM, or
115 // would confuse the SA's type system.
116 private static ObjectHeap heap;
117 private static long metadataFieldOffset;
118 private static long objectFieldOffset;
119 private static long ownerFieldOffset;
120 private static long nextOMFieldOffset;
121 private static CIntField contentionsField;
122 private static CIntField waitersField;
123 private static CIntegerField recursionsField;
124 private static long ANONYMOUS_OWNER;
125
126 // FIXME: expose platform-dependent stuff
127 }