serviceUtil.hpp revision 1472:c18cbe5936b8 
1/*
2 * Copyright (c) 2003, 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.
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23 */
24
25//
26// Serviceability utility functions.
27// (Shared by MM and JVMTI).
28//
29class ServiceUtil : public AllStatic {
30 public:
31
32  // Return true if oop represents an object that is "visible"
33  // to the java world.
34  static inline bool visible_oop(oop o) {
35    // the sentinel for deleted handles isn't visible
36    if (o == JNIHandles::deleted_handle()) {
37      return false;
38    }
39
40    // ignore KlassKlass
41    if (o->is_klass()) {
42      return false;
43    }
44
45    // instance
46    if (o->is_instance()) {
47      // instance objects are visible
48      if (o->klass() != SystemDictionary::Class_klass()) {
49        return true;
50      }
51      if (java_lang_Class::is_primitive(o)) {
52        return true;
53      }
54      // java.lang.Classes are visible
55      o = java_lang_Class::as_klassOop(o);
56      if (o->is_klass()) {
57        // if it's a class for an object, an object array, or
58        // primitive (type) array then it's visible.
59        klassOop klass = (klassOop)o;
60        if (Klass::cast(klass)->oop_is_instance()) {
61          return true;
62        }
63        if (Klass::cast(klass)->oop_is_objArray()) {
64          return true;
65        }
66        if (Klass::cast(klass)->oop_is_typeArray()) {
67          return true;
68        }
69      }
70      return false;
71    }
72    // object arrays are visible if they aren't system object arrays
73    if (o->is_objArray()) {
74      objArrayOop array = (objArrayOop)o;
75      if (array->klass() != Universe::systemObjArrayKlassObj()) {
76        return true;
77      } else {
78        return false;
79      }
80    }
81    // type arrays are visible
82    if (o->is_typeArray()) {
83      return true;
84    }
85    // everything else (methodOops, ...) aren't visible
86    return false;
87  };   // end of visible_oop()
88
89};
90