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.io.*;
  28 import java.util.*;
  29 import sun.jvm.hotspot.utilities.*;
  30 import sun.jvm.hotspot.debugger.*;
  31 import sun.jvm.hotspot.memory.*;
  32 import sun.jvm.hotspot.runtime.*;
  33 import sun.jvm.hotspot.types.*;
  34 
  35 // ArrayKlass is the abstract class for all array classes
  36 
  37 public class ArrayKlass extends Klass {
  38   static {
  39     VM.registerVMInitializedObserver(new Observer() {
  40         public void update(Observable o, Object data) {
  41           initialize(VM.getVM().getTypeDataBase());
  42         }
  43       });
  44   }
  45 
  46   private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
  47     Type type          = db.lookupType("ArrayKlass");
  48     dimension          = new CIntField(type.getCIntegerField("_dimension"), 0);
  49     higherDimension    = new MetadataField(type.getAddressField("_higher_dimension"), 0);
  50     lowerDimension     = new MetadataField(type.getAddressField("_lower_dimension"), 0);
  51     vtableLen          = new CIntField(type.getCIntegerField("_vtable_len"), 0);
  52     allocSize          = new CIntField(type.getCIntegerField("_alloc_size"), 0);
  53     componentMirror    = new OopField(type.getOopField("_component_mirror"), 0);
  54     javaLangCloneableName = null;
  55     javaLangObjectName = null;
  56     javaIoSerializableName = null;
  57   }
  58 
  59   public ArrayKlass(Address addr) {
  60     super(addr);
  61   }
  62 
  63   private static CIntField dimension;
  64   private static MetadataField  higherDimension;
  65   private static MetadataField  lowerDimension;
  66   private static CIntField vtableLen;
  67   private static CIntField allocSize;
  68   private static OopField  componentMirror;
  69 
  70   public Klass getJavaSuper() {
  71     SystemDictionary sysDict = VM.getVM().getSystemDictionary();
  72     return sysDict.getObjectKlass();
  73   }
  74 
  75   public long  getDimension()       { return         dimension.getValue(this); }
  76   public Klass getHigherDimension() { return (Klass) higherDimension.getValue(this); }
  77   public Klass getLowerDimension()  { return (Klass) lowerDimension.getValue(this); }
  78   public long  getVtableLen()       { return         vtableLen.getValue(this); }
  79   public long  getAllocSize()       { return         allocSize.getValue(this); }
  80   public Oop   getComponentMirror() { return         componentMirror.getValue(this); }
  81 
  82   // constant class names - javaLangCloneable, javaIoSerializable, javaLangObject
  83   // Initialized lazily to avoid initialization ordering dependencies between ArrayKlass and SymbolTable
  84   private static Symbol javaLangCloneableName;
  85   private static Symbol javaLangObjectName;
  86   private static Symbol javaIoSerializableName;
  87   private static Symbol javaLangCloneableName() {
  88     if (javaLangCloneableName == null) {
  89       javaLangCloneableName = VM.getVM().getSymbolTable().probe("java/lang/Cloneable");
  90     }
  91     return javaLangCloneableName;
  92   }
  93 
  94   private static Symbol javaLangObjectName() {
  95     if (javaLangObjectName == null) {
  96       javaLangObjectName = VM.getVM().getSymbolTable().probe("java/lang/Object");
  97     }
  98     return javaLangObjectName;
  99   }
 100 
 101   private static Symbol javaIoSerializableName() {
 102     if (javaIoSerializableName == null) {
 103       javaIoSerializableName = VM.getVM().getSymbolTable().probe("java/io/Serializable");
 104     }
 105     return javaIoSerializableName;
 106   }
 107 
 108   public int getClassStatus() {
 109      return JVMDIClassStatus.VERIFIED | JVMDIClassStatus.PREPARED | JVMDIClassStatus.INITIALIZED;
 110   }
 111 
 112   public long computeModifierFlags() {
 113      return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
 114   }
 115 
 116   public long getArrayHeaderInBytes() {
 117     return Bits.maskBits(getLayoutHelper() >> LH_HEADER_SIZE_SHIFT, 0xFF);
 118   }
 119 
 120   public int getLog2ElementSize() {
 121     return Bits.maskBits(getLayoutHelper() >> LH_LOG2_ELEMENT_SIZE_SHIFT, 0xFF);
 122   }
 123 
 124   public int getElementType() {
 125     return Bits.maskBits(getLayoutHelper() >> LH_ELEMENT_TYPE_SHIFT, 0xFF);
 126   }
 127 
 128   boolean computeSubtypeOf(Klass k) {
 129     // An array is a subtype of Serializable, Clonable, and Object
 130     Symbol name = k.getName();
 131     if (name != null && (name.equals(javaIoSerializableName()) ||
 132                          name.equals(javaLangCloneableName()) ||
 133                          name.equals(javaLangObjectName()))) {
 134       return true;
 135     } else {
 136       return false;
 137     }
 138   }
 139 
 140   public void printValueOn(PrintStream tty) {
 141     tty.print("ArrayKlass");
 142   }
 143 
 144   public void iterateFields(MetadataVisitor visitor) {
 145     super.iterateFields(visitor);
 146       visitor.doCInt(dimension, true);
 147     visitor.doMetadata(higherDimension, true);
 148     visitor.doMetadata(lowerDimension, true);
 149       visitor.doCInt(vtableLen, true);
 150       visitor.doCInt(allocSize, true);
 151       visitor.doOop(componentMirror, true);
 152     }
 153   }