1 /*
   2  * Copyright (c) 2001, 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.memory;
  26 
  27 import java.util.*;
  28 import sun.jvm.hotspot.debugger.*;
  29 import sun.jvm.hotspot.classfile.*;
  30 import sun.jvm.hotspot.oops.*;
  31 import sun.jvm.hotspot.runtime.*;
  32 import sun.jvm.hotspot.types.*;
  33 
  34 public class SystemDictionary {
  35   private static AddressField sharedDictionaryField;
  36   private static sun.jvm.hotspot.types.OopField javaSystemLoaderField;
  37 
  38   private static AddressField objectKlassField;
  39   private static AddressField classLoaderKlassField;
  40   private static AddressField stringKlassField;
  41   private static AddressField systemKlassField;
  42   private static AddressField threadKlassField;
  43   private static AddressField threadGroupKlassField;
  44   private static AddressField methodHandleKlassField;
  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("SystemDictionary");
  56 
  57     sharedDictionaryField = type.getAddressField("_shared_dictionary");
  58     javaSystemLoaderField = type.getOopField("_java_system_loader");
  59 
  60     objectKlassField = type.getAddressField(WK_KLASS("Object_klass"));
  61     classLoaderKlassField = type.getAddressField(WK_KLASS("ClassLoader_klass"));
  62     stringKlassField = type.getAddressField(WK_KLASS("String_klass"));
  63     systemKlassField = type.getAddressField(WK_KLASS("System_klass"));
  64     threadKlassField = type.getAddressField(WK_KLASS("Thread_klass"));
  65     threadGroupKlassField = type.getAddressField(WK_KLASS("ThreadGroup_klass"));
  66     methodHandleKlassField = type.getAddressField(WK_KLASS("MethodHandle_klass"));
  67   }
  68 
  69   // This WK functions must follow the definitions in systemDictionary.hpp:
  70   private static String WK_KLASS(String name) {
  71       //#define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
  72       return ("_well_known_klasses[SystemDictionary::"+WK_KLASS_ENUM_NAME(name)+"]");
  73   }
  74   private static String WK_KLASS_ENUM_NAME(String kname) {
  75       //#define WK_KLASS_ENUM_NAME(kname)    kname##_knum
  76       return (kname+"_knum");
  77   }
  78 
  79   public Dictionary sharedDictionary() {
  80     Address tmp = sharedDictionaryField.getValue();
  81     return (Dictionary) VMObjectFactory.newObject(Dictionary.class, tmp);
  82   }
  83 
  84   // few well known classes -- not all are added here.
  85   // add more if needed.
  86   public static InstanceKlass getThreadKlass() {
  87     return (InstanceKlass)Metadata.instantiateWrapperFor(threadKlassField.getValue());
  88   }
  89 
  90   public static InstanceKlass getThreadGroupKlass() {
  91     return (InstanceKlass)Metadata.instantiateWrapperFor(threadGroupKlassField.getValue());
  92   }
  93 
  94   public static InstanceKlass getObjectKlass() {
  95     return (InstanceKlass)Metadata.instantiateWrapperFor(objectKlassField.getValue());
  96   }
  97 
  98   public static InstanceKlass getStringKlass() {
  99     return (InstanceKlass)Metadata.instantiateWrapperFor(stringKlassField.getValue());
 100   }
 101 
 102   public static InstanceKlass getClassLoaderKlass() {
 103     return (InstanceKlass)Metadata.instantiateWrapperFor(classLoaderKlassField.getValue());
 104   }
 105 
 106   public static InstanceKlass getSystemKlass() {
 107     return (InstanceKlass)Metadata.instantiateWrapperFor(systemKlassField.getValue());
 108   }
 109 
 110   public static InstanceKlass getMethodHandleKlass() {
 111     return (InstanceKlass)Metadata.instantiateWrapperFor(methodHandleKlassField.getValue());
 112   }
 113 
 114   public InstanceKlass getAbstractOwnableSynchronizerKlass() {
 115     ClassLoaderDataGraph cldg = VM.getVM().getClassLoaderDataGraph();
 116     return (InstanceKlass) cldg.find("java/util/concurrent/locks/AbstractOwnableSynchronizer");
 117   }
 118 
 119   public static Oop javaSystemLoader() {
 120     return newOop(javaSystemLoaderField.getValue());
 121   }
 122 
 123   private static Oop newOop(OopHandle handle) {
 124     return VM.getVM().getObjectHeap().newOop(handle);
 125   }
 126 }