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.classfile.*;
  30 import sun.jvm.hotspot.oops.*;
  31 import sun.jvm.hotspot.types.*;
  32 import sun.jvm.hotspot.runtime.*;
  33 import sun.jvm.hotspot.utilities.*;
  34 
  35 public class Dictionary extends sun.jvm.hotspot.utilities.Hashtable {
  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   private static synchronized void initialize(TypeDataBase db) {
  45     // just checking that the type exists
  46     Type type = db.lookupType("Dictionary");
  47   }
  48 
  49   public Dictionary(Address addr) {
  50     super(addr);
  51   }
  52 
  53   // this is overriden here so that Hashtable.bucket will return
  54   // object of DictionaryEntry.class
  55   protected Class getHashtableEntryClass() {
  56     return DictionaryEntry.class;
  57   }
  58 
  59   /** All classes, and their initiating class loader, passed in. */
  60   public void allEntriesDo(ClassLoaderDataGraph.ClassAndLoaderVisitor v, Oop loader) {
  61     int tblSize = tableSize();
  62     for (int index = 0; index < tblSize; index++) {
  63       for (DictionaryEntry probe = (DictionaryEntry) bucket(index); probe != null;
  64                                               probe = (DictionaryEntry) probe.next()) {
  65         Klass k = probe.klass();
  66         v.visit(k, loader);
  67       }
  68     }
  69   }
  70 
  71   // - Internals only below this point
  72 
  73   private DictionaryEntry getEntry(int index, long hash, Symbol className) {
  74     for (DictionaryEntry entry = (DictionaryEntry) bucket(index); entry != null;
  75                                     entry = (DictionaryEntry) entry.next()) {
  76       if (entry.hash() == hash && entry.equals(className)) {
  77         return entry;
  78       }
  79     }
  80     return null;
  81   }
  82 
  83   public boolean contains(Klass c) {
  84     long hash = computeHash(c.getName());
  85     int index = hashToIndex(hash);
  86 
  87     for (DictionaryEntry entry = (DictionaryEntry) bucket(index); entry != null;
  88                                     entry = (DictionaryEntry) entry.next()) {
  89       if (entry.literalValue().equals(c.getAddress())) {
  90         return true;
  91       }
  92     }
  93     return false;
  94   }
  95 }