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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.utilities;
26  
27  import java.util.Observable;
28  import java.util.Observer;
29  
30  import sun.jvm.hotspot.debugger.Address;
31  import sun.jvm.hotspot.oops.Metadata;
32  import sun.jvm.hotspot.oops.Klass;
33  import sun.jvm.hotspot.runtime.VM;
34  import sun.jvm.hotspot.types.Type;
35  import sun.jvm.hotspot.types.TypeDataBase;
36  import sun.jvm.hotspot.types.WrongTypeException;
37  
38  public class KlassArray extends GenericArray {
39    static {
40      VM.registerVMInitializedObserver(new Observer() {
41        public void update(Observable o, Object data) {
42          initialize(VM.getVM().getTypeDataBase());
43        }
44      });
45    }
46  
47    private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
48      elemType = db.lookupType("Klass*");
49  
50      Type type = db.lookupType("Array<Klass*>");
51      dataFieldOffset = type.getAddressField("_data").getOffset();
52    }
53  
54    private static long dataFieldOffset;
55    protected static Type elemType;
56  
57    public KlassArray(Address addr) {
58      super(addr, dataFieldOffset);
59    }
60  
61    public Klass getAt(int i) {
62      return (Klass) Metadata.instantiateWrapperFor(getAddressAt(i));
63    }
64  
65    public Type getElemType() {
66      return elemType;
67    }
68  }