1 /*
   2  * Copyright (c) 2003, 2015, 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.gc.parallel;
  26 
  27 import java.io.*;
  28 import java.util.*;
  29 
  30 import sun.jvm.hotspot.debugger.*;
  31 import sun.jvm.hotspot.memory.*;
  32 import sun.jvm.hotspot.runtime.*;
  33 import sun.jvm.hotspot.types.*;
  34 
  35 public class MutableSpace extends ImmutableSpace {
  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) {
  45       Type type = db.lookupType("MutableSpace");
  46       topField    = type.getAddressField("_top");
  47    }
  48 
  49    public MutableSpace(Address addr) {
  50       super(addr);
  51    }
  52 
  53    // Fields
  54    private static AddressField topField;
  55 
  56    // Accessors
  57    public Address   top()          { return topField.getValue(addr);    }
  58 
  59    /** In bytes */
  60    public long used() {
  61       return top().minus(bottom());
  62    }
  63 
  64    /** returns all MemRegions where live objects are */
  65    public List/*<MemRegion>*/ getLiveRegions() {
  66       List res = new ArrayList();
  67       res.add(new MemRegion(bottom(), top()));
  68       return res;
  69    }
  70 
  71    public void printOn(PrintStream tty) {
  72       tty.print(" [" + bottom() + "," +
  73                 top() + "," + end() + "] ");
  74    }
  75 }