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().isCompressedHeadersEnabled()) {
  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().isCompressedHeadersEnabled()) {
  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 }