1 /*
   2  * @(#)FreeList.java
   3  *
   4  * Copyright (c) 2000, 2008, Oracle and/or its affiliates. All rights reserved.
   5  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   6  *
   7  * This code is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 only, as
   9  * published by the Free Software Foundation.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  *
  25  */
  26 
  27 package sun.jvm.hotspot.memory;
  28 
  29 import java.util.*;
  30 import sun.jvm.hotspot.debugger.*;
  31 import sun.jvm.hotspot.types.*;
  32 import sun.jvm.hotspot.runtime.*;
  33 
  34 public class FreeList 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) {
  44       Type type = db.lookupType("FreeList");
  45       sizeField = type.getCIntegerField("_size");
  46       countField = type.getCIntegerField("_count");
  47       headerSize = type.getSize();
  48    }
  49 
  50    // Fields
  51    private static CIntegerField sizeField;
  52    private static CIntegerField countField;
  53    private static long          headerSize;
  54 
  55    //Constructor
  56    public FreeList(Address address) {
  57      super(address);
  58    }
  59 
  60    // Accessors
  61    public long size() {
  62       return sizeField.getValue(addr);
  63    }
  64 
  65    public long count() {
  66       return  countField.getValue(addr);
  67    }
  68 
  69    public static long sizeOf() {
  70      return headerSize;
  71   }
  72 }