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