1 /*
2 * Copyright (c) 2011, 2015, 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
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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 // An InstanceMirrorKlass is a specialized InstanceKlass for
35 // java.lang.Class instances. These instances are special because
36 // they contain the static fields of the class in addition to the
37 // normal fields of Class. This means they are variable sized
38 // instances and need special logic for computing their size and for
39 // iteration of their oops.
40
41
42 class InstanceMirrorKlass: public InstanceKlass {
43 friend class VMStructs;
44 friend class InstanceKlass;
45
46 private:
47 static int _offset_of_static_fields;
48
49 // Constructor
50 InstanceMirrorKlass(int vtable_len, int itable_len, int static_field_size, int nonstatic_oop_map_size, ReferenceType rt, AccessFlags access_flags, bool is_anonymous)
51 : InstanceKlass(vtable_len, itable_len, static_field_size, nonstatic_oop_map_size,
52 InstanceKlass::_misc_kind_mirror, rt, access_flags, is_anonymous) {}
53
54 public:
55 InstanceMirrorKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
56
57 // Casting from Klass*
58 static InstanceMirrorKlass* cast(Klass* k) {
59 assert(InstanceKlass::cast(k)->is_mirror_instance_klass(),
60 "cast to InstanceMirrorKlass");
61 return static_cast<InstanceMirrorKlass*>(k);
62 }
63
64 // Returns the size of the instance including the extra static fields.
65 virtual int oop_size(oop obj) const;
66
67 // Static field offset is an offset into the Heap, should be converted by
68 // based on UseCompressedOop for traversal
69 static HeapWord* start_of_static_fields(oop obj) {
70 return (HeapWord*)(cast_from_oop<intptr_t>(obj) + offset_of_static_fields());
71 }
72
73 static void init_offset_of_static_fields() {
74 // Cache the offset of the static fields in the Class instance
75 assert(_offset_of_static_fields == 0, "once");
76 _offset_of_static_fields = InstanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize;
77 }
78
79 static int offset_of_static_fields() {
80 return _offset_of_static_fields;
81 }
82
83 int compute_static_oop_field_count(oop obj);
84
85 // Given a Klass return the size of the instance
86 int instance_size(KlassHandle k);
87
88 // allocation
89 instanceOop allocate_instance(KlassHandle k, TRAPS);
90
91 // GC specific object visitors
92 //
93 // Mark Sweep
94 int oop_ms_adjust_pointers(oop obj);
95 #if INCLUDE_ALL_GCS
96 // Parallel Scavenge
97 void oop_ps_push_contents( oop obj, PSPromotionManager* pm);
98 // Parallel Compact
99 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
100 void oop_pc_update_pointers(oop obj);
101 #endif
102
103 // Oop fields (and metadata) iterators
104 // [nv = true] Use non-virtual calls to do_oop_nv.
105 // [nv = false] Use virtual calls to do_oop.
106 //
107 // The InstanceMirrorKlass iterators also visit the hidden Klass pointer.
108
109 public:
110 // Iterate over the static fields.
111 template <bool nv, class OopClosureType>
112 inline void oop_oop_iterate_statics(oop obj, OopClosureType* closure);
113
114 private:
115 // Iterate over the static fields.
116 // Specialized for [T = oop] or [T = narrowOop].
117 template <bool nv, typename T, class OopClosureType>
118 inline void oop_oop_iterate_statics_specialized(oop obj, OopClosureType* closure);
119
120 // Forward iteration
121 // Iterate over the oop fields and metadata.
122 template <bool nv, class OopClosureType>
123 inline void oop_oop_iterate(oop obj, OopClosureType* closure);
124
125
126 // Reverse iteration
127 #if INCLUDE_ALL_GCS
128 // Iterate over the oop fields and metadata.
129 template <bool nv, class OopClosureType>
130 inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
131 #endif
132
133
134 // Bounded range iteration
135 // Iterate over the oop fields and metadata.
136 template <bool nv, class OopClosureType>
137 inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
138
139 // Iterate over the static fields.
140 template <bool nv, class OopClosureType>
141 inline void oop_oop_iterate_statics_bounded(oop obj, OopClosureType* closure, MemRegion mr);
142
143 // Iterate over the static fields.
144 // Specialized for [T = oop] or [T = narrowOop].
145 template <bool nv, typename T, class OopClosureType>
146 inline void oop_oop_iterate_statics_specialized_bounded(oop obj, OopClosureType* closure, MemRegion mr);
147
148
149 public:
150
151 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL)
152 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL)
153
154 #if INCLUDE_ALL_GCS
155 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS)
156 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS)
157 #endif // INCLUDE_ALL_GCS
158 };
159
160 #endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP