1 /*
   2  * Copyright (c) 2000, 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.shared;
  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 abstract class CollectedHeap extends VMObject {
  36   private static long         reservedFieldOffset;
  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 synchronized void initialize(TypeDataBase db) {
  47     Type type = db.lookupType("CollectedHeap");
  48 
  49     reservedFieldOffset = type.getField("_reserved").getOffset();
  50   }
  51 
  52   public CollectedHeap(Address addr) {
  53     super(addr);
  54   }
  55 
  56   /** Returns the lowest address of the heap. */
  57   public Address start() {
  58     return reservedRegion().start();
  59   }
  60 
  61   public long capacity() { return 0; }
  62   public long used()     { return 0; }
  63 
  64   public MemRegion reservedRegion() {
  65     return new MemRegion(addr.addOffsetTo(reservedFieldOffset));
  66   }
  67 
  68   public boolean isIn(Address a) {
  69     return isInReserved(a);
  70   }
  71 
  72   public boolean isInReserved(Address a) {
  73     return reservedRegion().contains(a);
  74   }
  75 
  76   public abstract CollectedHeapName kind();
  77 
  78   public String oopAddressDescription(OopHandle handle) {
  79       return handle.toString();
  80   }
  81 
  82   public OopHandle oop_load_at(OopHandle handle, long offset) {
  83       return handle.getOopHandleAt(offset);
  84   }
  85 
  86   public void print() { printOn(System.out); }
  87   public void printOn(PrintStream tty) {
  88     MemRegion mr = reservedRegion();
  89     tty.println("unknown subtype of CollectedHeap @ " + getAddress() + " (" +
  90                 mr.start() + "," + mr.end() + ")");
  91   }
  92 }