1 /*
   2  * Copyright (c) 2000, 2004, 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.compiler;
  26 
  27 import java.util.*;
  28 
  29 import sun.jvm.hotspot.code.*;
  30 import sun.jvm.hotspot.debugger.*;
  31 import sun.jvm.hotspot.runtime.*;
  32 import sun.jvm.hotspot.types.*;
  33 
  34 public class ImmutableOopMap extends VMObject {
  35   private static CIntegerField countField;
  36   private static long classSize;
  37 
  38   static {
  39     VM.registerVMInitializedObserver(new Observer() {
  40         public void update(Observable o, Object data) {
  41           initialize(VM.getVM().getTypeDataBase());
  42         }
  43       });
  44   }
  45 
  46   private static void initialize(TypeDataBase db) {
  47     Type type = db.lookupType("ImmutableOopMap");
  48     countField = type.getCIntegerField("_count");
  49     classSize = type.getSize();
  50   }
  51 
  52   public ImmutableOopMap(Address addr) {
  53     super(addr);
  54   }
  55 
  56   //--------------------------------------------------------------------------------
  57   // Internals only below this point
  58   //
  59 
  60   long getCount() {
  61     return countField.getValue(addr);
  62   }
  63 
  64   public Address getData() {
  65     return addr.addOffsetTo(classSize);
  66   }
  67 }