1 /*
2 * Copyright (c) 2011, 2017, 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 #ifndef SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP
26 #define SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP
27
28 #include "classfile/systemDictionary.hpp"
29 #include "gc/shared/specialized_oop_closures.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/macros.hpp"
33
34 class ClassFileParser;
35
36 // An InstanceMirrorKlass is a specialized InstanceKlass for
37 // java.lang.Class instances. These instances are special because
38 // they contain the static fields of the class in addition to the
39 // normal fields of Class. This means they are variable sized
40 // instances and need special logic for computing their size and for
41 // iteration of their oops.
42
43
44 class InstanceMirrorKlass: public InstanceKlass {
45 friend class VMStructs;
46 friend class InstanceKlass;
47
48 private:
49 static int _offset_of_static_fields;
50
51 InstanceMirrorKlass(const ClassFileParser& parser) : InstanceKlass(parser, InstanceKlass::_misc_kind_mirror) {}
52
53 public:
54 InstanceMirrorKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
55
56 // Casting from Klass*
57 static InstanceMirrorKlass* cast(Klass* k) {
58 assert(InstanceKlass::cast(k)->is_mirror_instance_klass(),
59 "cast to InstanceMirrorKlass");
60 return static_cast<InstanceMirrorKlass*>(k);
61 }
62
63 // Returns the size of the instance including the extra static fields.
64 virtual int oop_size(oop obj) const;
65
66 // Static field offset is an offset into the Heap, should be converted by
67 // based on UseCompressedOop for traversal
68 static HeapWord* start_of_static_fields(oop obj) {
69 return (HeapWord*)(cast_from_oop<intptr_t>(obj) + offset_of_static_fields());
70 }
71
72 static void init_offset_of_static_fields() {
73 // Cache the offset of the static fields in the Class instance
74 assert(_offset_of_static_fields == 0, "once");
75 _offset_of_static_fields = InstanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize;
76 }
77
78 static int offset_of_static_fields() {
79 return _offset_of_static_fields;
80 }
81
82 int compute_static_oop_field_count(oop obj);
83
84 // Given a Klass return the size of the instance
85 int instance_size(Klass* k);
86
87 // allocation
88 instanceOop allocate_instance(Klass* k, TRAPS);
89
90 // GC specific object visitors
91 //
92 #if INCLUDE_ALL_GCS
93 // Parallel Scavenge
94 void oop_ps_push_contents( oop obj, PSPromotionManager* pm);
95 // Parallel Compact
96 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
97 void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
98 #endif
99
100 // Oop fields (and metadata) iterators
101 // [nv = true] Use non-virtual calls to do_oop_nv.
102 // [nv = false] Use virtual calls to do_oop.
103 //
104 // The InstanceMirrorKlass iterators also visit the hidden Klass pointer.
105
106 public:
107 // Iterate over the static fields.
108 template <bool nv, class OopClosureType>
109 inline void oop_oop_iterate_statics(oop obj, OopClosureType* closure);
110
111 private:
112 // Iterate over the static fields.
113 // Specialized for [T = oop] or [T = narrowOop].
114 template <bool nv, typename T, class OopClosureType>
115 inline void oop_oop_iterate_statics_specialized(oop obj, OopClosureType* closure);
116
117 // Forward iteration
118 // Iterate over the oop fields and metadata.
119 template <bool nv, class OopClosureType>
120 inline void oop_oop_iterate(oop obj, OopClosureType* closure);
121
122
123 // Reverse iteration
124 #if INCLUDE_ALL_GCS
125 // Iterate over the oop fields and metadata.
126 template <bool nv, class OopClosureType>
127 inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
128 #endif
129
130
131 // Bounded range iteration
132 // Iterate over the oop fields and metadata.
133 template <bool nv, class OopClosureType>
134 inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
135
136 // Iterate over the static fields.
137 template <bool nv, class OopClosureType>
138 inline void oop_oop_iterate_statics_bounded(oop obj, OopClosureType* closure, MemRegion mr);
139
140 // Iterate over the static fields.
141 // Specialized for [T = oop] or [T = narrowOop].
142 template <bool nv, typename T, class OopClosureType>
143 inline void oop_oop_iterate_statics_specialized_bounded(oop obj, OopClosureType* closure, MemRegion mr);
144
145
146 public:
147
148 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL)
149 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL)
150
151 #if INCLUDE_ALL_GCS
152 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS)
153 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS)
154 #endif // INCLUDE_ALL_GCS
155 };
156
157 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP