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1   /*
2    * Copyright (c) 2001, 2005, 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  
33  public class ObjectMonitor extends VMObject {
34    static {
35      VM.registerVMInitializedObserver(new Observer() {
36          public void update(Observable o, Object data) {
37            initialize(VM.getVM().getTypeDataBase());
38          }
39        });
40    }
41  
42    private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
43      heap = VM.getVM().getObjectHeap();
44      Type type  = db.lookupType("ObjectMonitor");
45      sun.jvm.hotspot.types.Field f = type.getField("_header");
46      headerFieldOffset = f.getOffset();
47      f = type.getField("_object");
48      objectFieldOffset = f.getOffset();
49      f = type.getField("_owner");
50      ownerFieldOffset = f.getOffset();
51      f = type.getField("FreeNext");
52      FreeNextFieldOffset = f.getOffset();
53      countField  = type.getCIntegerField("_count");
54      waitersField = type.getCIntegerField("_waiters");
55      recursionsField = type.getCIntegerField("_recursions");
56    }
57  
58    public ObjectMonitor(Address addr) {
59      super(addr);
60    }
61  
62    public Mark header() {
63      return new Mark(addr.addOffsetTo(headerFieldOffset));
64    }
65  
66    // FIXME
67    //  void      set_header(markOop hdr);
68  
69    // FIXME: must implement and delegate to platform-dependent implementation
70    //  public boolean isBusy();
71    public boolean isEntered(sun.jvm.hotspot.runtime.Thread current) {
72      Address o = owner();
73      if (current.threadObjectAddress().equals(o) ||
74          current.isLockOwned(o)) {
75        return true;
76      }
77      return false;
78    }
79  
80    public Address owner() { return addr.getAddressAt(ownerFieldOffset); }
81    // FIXME
82    //  void      set_owner(void* owner);
83  
84    public long    waiters() { return waitersField.getValue(addr); }
85  
86    public Address freeNext() { return addr.getAddressAt(FreeNextFieldOffset); }
87    // FIXME
88    //  void      set_queue(void* owner);
89  
90    public long count() { return countField.getValue(addr); }
91    // FIXME
92    //  void      set_count(intptr_t count);
93  
94    public long recursions() { return recursionsField.getValue(addr); }
95  
96    public OopHandle object() {
97      return addr.getOopHandleAt(objectFieldOffset);
98    }
99  
100   public long contentions() {
101       // refer to objectMonitor_xxx.inline.hpp - contentions definition.
102       // for Solaris and Linux, contentions is same as count. for Windows
103       // it is different (objectMonitor_win32.inline.hpp)
104       long count = count();
105       if (VM.getVM().getOS().equals("win32")) {
106           // don't count the owner of the monitor
107           return count > 0? count - 1 : 0;
108       } else {
109           // Solaris and Linux
110           return count;
111       }
112   }
113 
114   // FIXME
115   //  void*     object_addr();
116   //  void      set_object(void* obj);
117 
118   // The following four either aren't expressed as typed fields in
119   // vmStructs.cpp because they aren't strongly typed in the VM, or
120   // would confuse the SA's type system.
121   private static ObjectHeap    heap;
122   private static long          headerFieldOffset;
123   private static long          objectFieldOffset;
124   private static long          ownerFieldOffset;
125   private static long          FreeNextFieldOffset;
126   private static CIntegerField countField;
127   private static CIntegerField waitersField;
128   private static CIntegerField recursionsField;
129   // FIXME: expose platform-dependent stuff
130 }