1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 package sun.jvm.hotspot.gc_implementation.shenandoah;
  25 
  26 import sun.jvm.hotspot.memory.ContiguousSpace;
  27 import sun.jvm.hotspot.types.AddressField;
  28 import sun.jvm.hotspot.types.CIntegerField;
  29 import sun.jvm.hotspot.runtime.VM;
  30 import sun.jvm.hotspot.runtime.VMObject;
  31 import sun.jvm.hotspot.types.Type;
  32 import sun.jvm.hotspot.types.TypeDataBase;
  33 import sun.jvm.hotspot.debugger.Address;
  34 
  35 import java.util.Observable;
  36 import java.util.Observer;
  37 
  38 
  39 public class ShenandoahHeapRegion extends VMObject {
  40     private static CIntegerField RegionSizeBytes;
  41 
  42     private static AddressField BottomField;
  43     private static AddressField TopField;
  44     private static AddressField EndField;
  45 
  46     static {
  47         VM.registerVMInitializedObserver(new Observer() {
  48             public void update(Observable o, Object data) {
  49                 initialize(VM.getVM().getTypeDataBase());
  50             }
  51         });
  52     }
  53 
  54     static private synchronized void initialize(TypeDataBase db) {
  55         Type type = db.lookupType("ShenandoahHeapRegion");
  56         RegionSizeBytes = type.getCIntegerField("RegionSizeBytes");
  57 
  58         BottomField = type.getAddressField("_bottom");
  59         TopField = type.getAddressField("_top");
  60         EndField = type.getAddressField("_end");
  61     }
  62 
  63     public static long regionSizeBytes() { return RegionSizeBytes.getValue(); }
  64 
  65     public ShenandoahHeapRegion(Address addr) {
  66         super(addr);
  67     }
  68 
  69     public Address bottom() {
  70         return BottomField.getValue(addr);
  71     }
  72 
  73     public Address top() {
  74         return TopField.getValue(addr);
  75     }
  76 
  77     public Address end() {
  78         return EndField.getValue(addr);
  79     }
  80 }