1 /*
   2  * Copyright (c) 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.classfile;
  26 
  27 import java.io.PrintStream;
  28 import java.util.*;
  29 import sun.jvm.hotspot.debugger.*;
  30 import sun.jvm.hotspot.runtime.*;
  31 import sun.jvm.hotspot.oops.*;
  32 import sun.jvm.hotspot.types.*;
  33 
  34 public class ClassLoaderDataGraph {
  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) throws WrongTypeException {
  44     Type type = db.lookupType("ClassLoaderDataGraph");
  45 
  46     headField = type.getAddressField("_head");
  47   }
  48 
  49   private static AddressField headField;
  50 
  51   public ClassLoaderData getClassLoaderGraphHead() {
  52     return ClassLoaderData.instantiateWrapperFor(headField.getValue());
  53   }
  54 
  55   public static interface KlassVisitor {
  56     public void visit(Klass k);
  57   }
  58 
  59   /** Iterate over all anonymous class loaders and the klasses in those */
  60   public void allAnonymousKlassesDo(final KlassVisitor v) {
  61     for (ClassLoaderData cl = getClassLoaderGraphHead();
  62          cl != null;
  63          cl = cl.next()) {
  64       if (cl.getIsAnonymous() == true) {
  65         for (Klass k = cl.getKlasses(); k != null; k = k.getNextLinkKlass()) {
  66           v.visit(k);
  67         }
  68       }
  69     }
  70   }
  71 
  72 }