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1   /*
2    * Copyright (c) 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.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 ClassLoaderData extends VMObject {
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("ClassLoaderData");
45      classLoaderField = type.getOopField("_class_loader");
46      nextField = type.getAddressField("_next");
47    }
48  
49    private static sun.jvm.hotspot.types.OopField classLoaderField;
50    private static AddressField nextField;
51  
52    public ClassLoaderData(Address addr) {
53      super(addr);
54    }
55  
56    public static ClassLoaderData instantiateWrapperFor(Address addr) {
57      if (addr == null) {
58        return null;
59      }
60      return new ClassLoaderData(addr);
61    }
62  
63    public Oop getClassLoader() {
64      return VM.getVM().getObjectHeap().newOop(classLoaderField.getValue(getAddress()));
65    }
66  }