1 /*
   2  * Copyright (c) 2003, 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.oops.*;
  30 import sun.jvm.hotspot.types.*;
  31 import sun.jvm.hotspot.runtime.*;
  32 import sun.jvm.hotspot.utilities.*;
  33 
  34 public class Dictionary extends TwoOopHashtable {
  35   static {
  36     VM.registerVMInitializedObserver(new Observer() {
  37         public void update(Observable o, Object data) {
  38           initialize(VM.getVM().getTypeDataBase());
  39         }
  40       });
  41   }
  42 
  43   private static synchronized void initialize(TypeDataBase db) {
  44     // just checking that the type exists
  45     Type type = db.lookupType("Dictionary");
  46   }
  47 
  48   public Dictionary(Address addr) {
  49     super(addr);
  50   }
  51 
  52   // this is overriden here so that Hashtable.bucket will return
  53   // object of DictionaryEntry.class
  54   protected Class getHashtableEntryClass() {
  55     return DictionaryEntry.class;
  56   }
  57 
  58   /** Iterate over all klasses in dictionary; just the classes from
  59       declaring class loaders */
  60   public void classesDo(SystemDictionary.ClassVisitor v) {
  61     ObjectHeap heap = VM.getVM().getObjectHeap();
  62     int tblSize = tableSize();
  63     for (int index = 0; index < tblSize; index++) {
  64       for (DictionaryEntry probe = (DictionaryEntry) bucket(index); probe != null;
  65                                              probe = (DictionaryEntry) probe.next()) {
  66         Klass k = probe.klass();
  67         if (heap.equal(probe.loader(), ((InstanceKlass) k).getClassLoader())) {
  68             v.visit(k);
  69         }
  70       }
  71     }
  72   }
  73 
  74   /** All classes, and their class loaders */
  75   public void classesDo(SystemDictionary.ClassAndLoaderVisitor v) {
  76     int tblSize = tableSize();
  77     for (int index = 0; index < tblSize; index++) {
  78       for (DictionaryEntry probe = (DictionaryEntry) bucket(index); probe != null;
  79                                              probe = (DictionaryEntry) probe.next()) {
  80         Klass k = probe.klass();
  81         v.visit(k, probe.loader());
  82       }
  83     }
  84   }
  85 
  86   public Klass find(int index, long hash, Symbol className, Oop classLoader, Oop protectionDomain) {
  87     DictionaryEntry entry = getEntry(index, hash, className, classLoader);
  88     if (entry != null && entry.isValidProtectionDomain(protectionDomain)) {
  89       return entry.klass();
  90     }
  91     return null;
  92   }
  93 
  94   // - Internals only below this point
  95 
  96   private DictionaryEntry getEntry(int index, long hash, Symbol className, Oop classLoader) {
  97     for (DictionaryEntry entry = (DictionaryEntry) bucket(index); entry != null;
  98                                     entry = (DictionaryEntry) entry.next()) {
  99       if (entry.hash() == hash && entry.equals(className, classLoader)) {
 100         return entry;
 101       }
 102     }
 103     return null;
 104   }
 105 }