1 /*

     2  * Copyright (c) 2000, 2012, 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.oops;

    26 

    27 import java.util.*;

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

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

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

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

    32 

    33 // Array is an abstract superclass for TypeArray and ObjArray

    34 

    35 public class Array extends Oop {

    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   Array(OopHandle handle, ObjectHeap heap) {

    45     super(handle, heap);

    46   }

    47 

    48   private static void initialize(TypeDataBase db) throws WrongTypeException {

    49     Type type   = db.lookupType("arrayOopDesc");

    50     typeSize    = (int)type.getSize();

    51   }

    52 

    53   // Size of the arrayOopDesc

    54   private static long headerSize=0;

    55   private static long lengthOffsetInBytes=0;

    56   private static long typeSize;

    57 

    58   private static long headerSizeInBytes() {

    59     if (headerSize != 0) {

    60       return headerSize;

    61     }

    62     if (VM.getVM().isCompressedKlassPointersEnabled()) {

    63       headerSize = typeSize;

    64     } else {

    65       headerSize = VM.getVM().alignUp(typeSize + VM.getVM().getIntSize(),

    66                                       VM.getVM().getHeapWordSize());

    67     }

    68     return headerSize;

    69   }

    70 

    71   private static long headerSize(BasicType type) {

    72     if (Universe.elementTypeShouldBeAligned(type)) {

    73        return alignObjectSize(headerSizeInBytes())/VM.getVM().getHeapWordSize();

    74     } else {

    75       return headerSizeInBytes()/VM.getVM().getHeapWordSize();

    76     }

    77   }

    78 

    79   private long lengthOffsetInBytes() {

    80     if (lengthOffsetInBytes != 0) {

    81       return lengthOffsetInBytes;

    82     }

    83     if (VM.getVM().isCompressedKlassPointersEnabled()) {

    84       lengthOffsetInBytes = typeSize - VM.getVM().getIntSize();

    85     } else {

    86       lengthOffsetInBytes = typeSize;

    87     }

    88     return lengthOffsetInBytes;

    89   }

    90 

    91   // Accessors for declared fields

    92   public long getLength() {

    93     boolean isUnsigned = true;

    94     return this.getHandle().getCIntegerAt(lengthOffsetInBytes(), VM.getVM().getIntSize(), isUnsigned);

    95   }

    96 

    97   public long getObjectSize() {

    98     ArrayKlass klass = (ArrayKlass) getKlass();

    99     // We have to fetch the length of the array, shift (multiply) it

   100     // appropriately, up to wordSize, add the header, and align to

   101     // object size.

   102     long s = getLength() << klass.getLog2ElementSize();

   103     s += klass.getArrayHeaderInBytes();

   104     s = Oop.alignObjectSize(s);

   105     return s;

   106   }

   107 

   108   public static long baseOffsetInBytes(BasicType type) {

   109     return headerSize(type) * VM.getVM().getHeapWordSize();

   110   }

   111 

   112   public boolean isArray()             { return true; }

   113 

   114   public void iterateFields(OopVisitor visitor, boolean doVMFields) {

   115     super.iterateFields(visitor, doVMFields);

   116   }

   117 }