1 /*
   2  * Copyright (c) 2018, 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.z;
  26 
  27 import sun.jvm.hotspot.debugger.Address;
  28 import sun.jvm.hotspot.runtime.VM;
  29 import sun.jvm.hotspot.runtime.VMObject;
  30 import sun.jvm.hotspot.types.Type;
  31 import sun.jvm.hotspot.types.TypeDataBase;
  32 
  33 class ZPageTable  extends VMObject {
  34     private static long mapFieldOffset;
  35 
  36     static {
  37         VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
  38     }
  39 
  40     static private synchronized void initialize(TypeDataBase db) {
  41         Type type = db.lookupType("ZPageTable");
  42 
  43         mapFieldOffset = type.getAddressField("_map").getOffset();
  44     }
  45 
  46     private ZAddressRangeMapForPageTable map() {
  47         return new ZAddressRangeMapForPageTable(addr.addOffsetTo(mapFieldOffset));
  48     }
  49 
  50     private ZPageTableEntry getEntry(Address o) {
  51         return new ZPageTableEntry(map().get(o));
  52     }
  53 
  54     ZPage get(Address o) {
  55         return getEntry(o).page();
  56     }
  57 
  58     boolean is_relocating(Address o) {
  59         return getEntry(o).relocating();
  60     }
  61 
  62     ZPageTable(Address addr) {
  63         super(addr);
  64     }
  65 }