1 /*
   2  * Copyright (c) 2000, 2016, 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     javaLangCloneableName = null;
  52     javaLangObjectName = null;
  53     javaIoSerializableName = null;
  54   }
  55 
  56   public ArrayKlass(Address addr) {
  57     super(addr);
  58   }
  59 
  60   private static CIntField dimension;
  61   private static MetadataField  higherDimension;
  62   private static MetadataField  lowerDimension;
  63 
  64   public Klass getJavaSuper() {
  65     SystemDictionary sysDict = VM.getVM().getSystemDictionary();
  66     return sysDict.getObjectKlass();
  67   }
  68 
  69   public long  getDimension()       { return         dimension.getValue(this); }
  70   public Klass getHigherDimension() { return (Klass) higherDimension.getValue(this); }
  71   public Klass getLowerDimension()  { return (Klass) lowerDimension.getValue(this); }
  72 
  73   // constant class names - javaLangCloneable, javaIoSerializable, javaLangObject
  74   // Initialized lazily to avoid initialization ordering dependencies between ArrayKlass and SymbolTable
  75   private static Symbol javaLangCloneableName;
  76   private static Symbol javaLangObjectName;
  77   private static Symbol javaIoSerializableName;
  78   private static Symbol javaLangCloneableName() {
  79     if (javaLangCloneableName == null) {
  80       javaLangCloneableName = VM.getVM().getSymbolTable().probe("java/lang/Cloneable");
  81     }
  82     return javaLangCloneableName;
  83   }
  84 
  85   private static Symbol javaLangObjectName() {
  86     if (javaLangObjectName == null) {
  87       javaLangObjectName = VM.getVM().getSymbolTable().probe("java/lang/Object");
  88     }
  89     return javaLangObjectName;
  90   }
  91 
  92   private static Symbol javaIoSerializableName() {
  93     if (javaIoSerializableName == null) {
  94       javaIoSerializableName = VM.getVM().getSymbolTable().probe("java/io/Serializable");
  95     }
  96     return javaIoSerializableName;
  97   }
  98 
  99   public int getClassStatus() {
 100      return JVMDIClassStatus.VERIFIED | JVMDIClassStatus.PREPARED | JVMDIClassStatus.INITIALIZED;
 101   }
 102 
 103   public long computeModifierFlags() {
 104      return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
 105   }
 106 
 107   public long getArrayHeaderInBytes() {
 108     return Bits.maskBits(getLayoutHelper() >> LH_HEADER_SIZE_SHIFT, 0xFF);
 109   }
 110 
 111   public int getLog2ElementSize() {
 112     return Bits.maskBits(getLayoutHelper() >> LH_LOG2_ELEMENT_SIZE_SHIFT, 0xFF);
 113   }
 114 
 115   public int getElementType() {
 116     return Bits.maskBits(getLayoutHelper() >> LH_ELEMENT_TYPE_SHIFT, 0xFF);
 117   }
 118 
 119   boolean computeSubtypeOf(Klass k) {
 120     // An array is a subtype of Serializable, Clonable, and Object
 121     Symbol name = k.getName();
 122     if (name != null && (name.equals(javaIoSerializableName()) ||
 123                          name.equals(javaLangCloneableName()) ||
 124                          name.equals(javaLangObjectName()))) {
 125       return true;
 126     } else {
 127       return false;
 128     }
 129   }
 130 
 131   public void printValueOn(PrintStream tty) {
 132     tty.print("ArrayKlass");
 133   }
 134 
 135   public void iterateFields(MetadataVisitor visitor) {
 136     super.iterateFields(visitor);
 137       visitor.doCInt(dimension, true);
 138     visitor.doMetadata(higherDimension, true);
 139     visitor.doMetadata(lowerDimension, true);
 140     }
 141   }