1 /*
 2  * Copyright (c) 2012, 2026, 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.oops;
26 
27 import java.io.*;
28 import java.util.*;
29 import sun.jvm.hotspot.memory.*;
30 import sun.jvm.hotspot.utilities.*;
31 import sun.jvm.hotspot.debugger.*;
32 import sun.jvm.hotspot.runtime.*;
33 import sun.jvm.hotspot.types.*;
34 import sun.jvm.hotspot.utilities.Observable;
35 import sun.jvm.hotspot.utilities.Observer;
36 
37 public abstract class Metadata extends VMObject {
38   static {
39     VM.registerVMInitializedObserver(new Observer() {
40         public void update(Observable o, Object data) {
41           initialize(VM.getVM().getTypeDataBase());
42         }
43       });
44   }
45 
46   public Metadata(Address addr) {
47     super(addr);
48   }
49 
50   public static long alignSize(long size) {
51     // natural word size.
52     return VM.getVM().alignUp(size, VM.getVM().getBytesPerWord());
53   }
54 
55   private static VirtualBaseConstructor<Metadata> metadataConstructor;
56 
57   private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
58     metadataConstructor = new VirtualBaseConstructor<>(db, db.lookupType("Metadata"), null, null);
59     // Define an explicit mapping since the C++ and Java type names don't match.
60     metadataConstructor.addMapping("Metadata", Metadata.class);
61     metadataConstructor.addMapping("Klass", Klass.class);
62     metadataConstructor.addMapping("InstanceKlass", InstanceKlass.class);
63     metadataConstructor.addMapping("InstanceMirrorKlass", InstanceMirrorKlass.class);
64     metadataConstructor.addMapping("InstanceRefKlass", InstanceRefKlass.class);
65     metadataConstructor.addMapping("InstanceClassLoaderKlass", InstanceClassLoaderKlass.class);
66     metadataConstructor.addMapping("InstanceStackChunkKlass", InstanceStackChunkKlass.class);
67     metadataConstructor.addMapping("TypeArrayKlass", TypeArrayKlass.class);
68     metadataConstructor.addMapping("ObjArrayKlass", ObjArrayKlass.class);
69     metadataConstructor.addMapping("Method", Method.class);
70     metadataConstructor.addMapping("ConstMethod", ConstMethod.class);
71     metadataConstructor.addMapping("ConstantPool", ConstantPool.class);
72     metadataConstructor.addMapping("ConstantPoolCache", ConstantPoolCache.class);
73     metadataConstructor.addMapping("Annotations", Annotations.class);
74   }
75 
76   public static Metadata instantiateWrapperFor(Address addr) {
77     return metadataConstructor.instantiateWrapperFor(addr);
78   }
79 
80   public void iterate(MetadataVisitor visitor) {
81     visitor.setObj(this);
82     visitor.prologue();
83     iterateFields(visitor);
84     visitor.epilogue();
85   }
86 
87   void iterateFields(MetadataVisitor visitor) {
88   }
89 
90   public abstract void printValueOn(PrintStream tty);
91 
92   public boolean isShared() {
93     VM vm = VM.getVM();
94     if (vm.isSharingEnabled()) {
95       return MetaspaceObj.isShared(getAddress());
96     }
97     return false;
98   }
99 }