1 /*

     2  * Copyright (c) 2007, 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.cms;

    26 

    27 import java.io.*;

    28 import java.util.*;

    29 import sun.jvm.hotspot.debugger.*;

    30 import sun.jvm.hotspot.memory.*;

    31 import sun.jvm.hotspot.runtime.*;

    32 import sun.jvm.hotspot.types.*;

    33 import sun.jvm.hotspot.utilities.*;

    34 

    35 public class CMSBitMap extends VMObject {

    36   private static AddressField bmStartWordField;

    37   private static CIntegerField bmWordSizeField;

    38   private static CIntegerField shifterField;

    39   //private static AddressField bmField;

    40   private static long virtualSpaceFieldOffset;

    41 

    42   public CMSBitMap(Address addr) {

    43     super(addr);

    44   }

    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   private static synchronized void initialize(TypeDataBase db) {

    55     Type type = db.lookupType("CMSBitMap");

    56     bmStartWordField = type.getAddressField("_bmStartWord");

    57     bmWordSizeField = type.getCIntegerField("_bmWordSize");

    58     shifterField = type.getCIntegerField("_shifter");

    59     //bmField = type.getAddressField("_bm");

    60     virtualSpaceFieldOffset = type.getField("_virtual_space").getOffset();

    61   }

    62   public void printAll() {

    63     System.out.println("bmStartWord(): "+bmStartWord());

    64     System.out.println("bmWordSize(): "+bmWordSize());

    65     System.out.println("shifter(): "+shifter());

    66   }

    67 

    68   public Address bmStartWord() {

    69     return bmStartWordField.getValue(addr);

    70   }

    71   public long bmWordSize() {

    72     return bmWordSizeField.getValue(addr);

    73   }

    74   public long shifter() {

    75     return shifterField.getValue(addr);

    76   }

    77   public VirtualSpace virtualSpace() {

    78     return (VirtualSpace) VMObjectFactory.newObject(VirtualSpace.class, addr.addOffsetTo(virtualSpaceFieldOffset));

    79   }

    80 

    81   public BitMap bm() {

    82     BitMap bitMap = new BitMap((int) (bmWordSize() >> shifter() ));

    83     VirtualSpace vs = virtualSpace();

    84     bitMap.set_map(vs.low());

    85     return bitMap;

    86   }

    87 

    88   public Address getNextMarkedWordAddress(Address addr) {

    89     Address endWord = bmStartWord().addOffsetTo(bmWordSize());

    90     int nextOffset = bm().getNextOneOffset(heapWordToOffset(addr), heapWordToOffset(endWord) );

    91     Address nextAddr = offsetToHeapWord(nextOffset);

    92     return nextAddr;

    93   }

    94 

    95   int heapWordToOffset(Address addr) {

    96     int temp = (int)addr.minus(bmStartWord()) / (int) VM.getVM().getAddressSize();

    97     int ret_val = temp >> shifter();

    98     return ret_val;

    99   }

   100 

   101   Address offsetToHeapWord(int offset) {

   102     int temp = offset << shifter();

   103     return bmStartWord().addOffsetTo(temp*VM.getVM().getAddressSize());

   104   }

   105 

   106   boolean isMarked(Address addr) {

   107     BitMap bm = bm();

   108     return bm.at(heapWordToOffset(addr));

   109   }

   110 }