1 /*
2 * Copyright (c) 2014, 2025, 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_MEMORY_ITERATOR_INLINE_HPP
26 #define SHARE_MEMORY_ITERATOR_INLINE_HPP
27
28 #include "memory/iterator.hpp"
29
30 #include "classfile/classLoaderData.hpp"
31 #include "code/nmethod.hpp"
32 #include "oops/access.inline.hpp"
33 #include "oops/compressedOops.inline.hpp"
34 #include "oops/instanceClassLoaderKlass.inline.hpp"
35 #include "oops/instanceKlass.inline.hpp"
36 #include "oops/instanceMirrorKlass.inline.hpp"
37 #include "oops/instanceRefKlass.inline.hpp"
38 #include "oops/instanceStackChunkKlass.inline.hpp"
39 #include "oops/klass.hpp"
40 #include "oops/objArrayKlass.inline.hpp"
41 #include "oops/typeArrayKlass.inline.hpp"
42 #include "utilities/debug.hpp"
43
44 // Defaults to strong claiming.
45 inline MetadataVisitingOopIterateClosure::MetadataVisitingOopIterateClosure(ReferenceDiscoverer* rd) :
46 ClaimMetadataVisitingOopIterateClosure(ClassLoaderData::_claim_strong, rd) {}
47
48 inline void ClaimMetadataVisitingOopIterateClosure::do_cld(ClassLoaderData* cld) {
49 cld->oops_do(this, _claim);
50 }
51
52 inline void ClaimMetadataVisitingOopIterateClosure::do_klass(Klass* k) {
53 ClaimMetadataVisitingOopIterateClosure::do_cld(k->class_loader_data());
54 }
55
56 inline void ClaimMetadataVisitingOopIterateClosure::do_nmethod(nmethod* nm) {
57 nm->follow_nmethod(this);
58 }
59
60 inline void ClaimMetadataVisitingOopIterateClosure::do_method(Method* m) {
61 // Mark interpreted frames for class redefinition
62 m->record_gc_epoch();
63 }
64
65 // Dispatch table implementation for *Klass::oop_oop_iterate
66 //
67 // It allows for a single call to do a multi-dispatch to an optimized version
68 // of oop_oop_iterate that statically know all these types:
69 // - OopClosureType : static type give at call site
70 // - Klass* : dynamic to static type through Klass::kind() -> table index
71 // - UseCompressedOops : dynamic to static value determined once
72 //
73 // when users call obj->oop_iterate(&cl).
74 //
75 // oopDesc::oop_iterate() calls OopOopIterateDispatch::function(klass)(cl, obj, klass),
76 // which dispatches to an optimized version of
77 // [Instance, ObjArry, etc]Klass::oop_oop_iterate(oop, OopClosureType)
78 //
79 // OopClosureType :
80 // If OopClosureType has an implementation of do_oop (and do_metadata et.al.),
81 // then the static type of OopClosureType will be used to allow inlining of
82 // do_oop (even though do_oop is virtual). Otherwise, a virtual call will be
83 // used when calling do_oop.
84 //
85 // Klass* :
86 // A table mapping from *Klass::Kind to function is setup. This happens once
87 // when the program starts, when the static _table instance is initialized for
88 // the OopOopIterateDispatch specialized with the OopClosureType.
89 //
90 // UseCompressedOops :
91 // Initially the table is populated with an init function, and not the actual
92 // oop_oop_iterate function. This is done, so that the first time we dispatch
93 // through the init function we check what the value of UseCompressedOops
94 // became, and use that to determine if we should install an optimized
95 // narrowOop version or optimized oop version of oop_oop_iterate. The appropriate
96 // oop_oop_iterate function replaces the init function in the table, and
97 // succeeding calls will jump directly to oop_oop_iterate.
98
99
100 template <typename OopClosureType>
101 class OopOopIterateDispatch : public AllStatic {
102 private:
103 typedef void (*FunctionType)(OopClosureType*, oop, Klass*);
104
105 class Table {
106 private:
107 template <typename KlassType, typename T>
108 static void oop_oop_iterate(OopClosureType* cl, oop obj, Klass* k) {
109 ((KlassType*)k)->KlassType::template oop_oop_iterate<T>(obj, cl);
110 }
111
112 template <typename KlassType>
113 static void init(OopClosureType* cl, oop obj, Klass* k) {
114 OopOopIterateDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
115 }
116
117 template <typename KlassType>
118 void set_init_function() {
119 _function[KlassType::Kind] = &init<KlassType>;
120 }
121
122 template <typename KlassType>
123 void set_resolve_function() {
124 // Size requirement to prevent word tearing
125 // when functions pointers are updated.
126 STATIC_ASSERT(sizeof(_function[0]) == sizeof(void*));
127 if (UseCompressedOops) {
128 _function[KlassType::Kind] = &oop_oop_iterate<KlassType, narrowOop>;
129 } else {
130 _function[KlassType::Kind] = &oop_oop_iterate<KlassType, oop>;
131 }
132 }
133
134 template <typename KlassType>
135 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
136 set_resolve_function<KlassType>();
137 _function[KlassType::Kind](cl, obj, k);
138 }
139
140 public:
141 FunctionType _function[Klass::KLASS_KIND_COUNT];
142
143 Table(){
144 set_init_function<InstanceKlass>();
145 set_init_function<InstanceRefKlass>();
146 set_init_function<InstanceMirrorKlass>();
147 set_init_function<InstanceClassLoaderKlass>();
148 set_init_function<InstanceStackChunkKlass>();
149 set_init_function<ObjArrayKlass>();
150 set_init_function<TypeArrayKlass>();
151 }
152 };
153
154 static Table _table;
155 public:
156
157 static FunctionType function(Klass* klass) {
158 return _table._function[klass->kind()];
159 }
160 };
161
162 template <typename OopClosureType>
163 typename OopOopIterateDispatch<OopClosureType>::Table OopOopIterateDispatch<OopClosureType>::_table;
164
165
166 template <typename OopClosureType>
167 class OopOopIterateBoundedDispatch {
168 private:
169 typedef void (*FunctionType)(OopClosureType*, oop, Klass*, MemRegion);
170
171 class Table {
172 private:
173 template <typename KlassType, typename T>
174 static void oop_oop_iterate_bounded(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
175 ((KlassType*)k)->KlassType::template oop_oop_iterate_bounded<T>(obj, cl, mr);
176 }
177
178 template <typename KlassType>
179 static void init(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
180 OopOopIterateBoundedDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k, mr);
181 }
182
183 template <typename KlassType>
184 void set_init_function() {
185 _function[KlassType::Kind] = &init<KlassType>;
186 }
187
188 template <typename KlassType>
189 void set_resolve_function() {
190 if (UseCompressedOops) {
191 _function[KlassType::Kind] = &oop_oop_iterate_bounded<KlassType, narrowOop>;
192 } else {
193 _function[KlassType::Kind] = &oop_oop_iterate_bounded<KlassType, oop>;
194 }
195 }
196
197 template <typename KlassType>
198 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
199 set_resolve_function<KlassType>();
200 _function[KlassType::Kind](cl, obj, k, mr);
201 }
202
203 public:
204 FunctionType _function[Klass::KLASS_KIND_COUNT];
205
206 Table(){
207 set_init_function<InstanceKlass>();
208 set_init_function<InstanceRefKlass>();
209 set_init_function<InstanceMirrorKlass>();
210 set_init_function<InstanceClassLoaderKlass>();
211 set_init_function<InstanceStackChunkKlass>();
212 set_init_function<ObjArrayKlass>();
213 set_init_function<TypeArrayKlass>();
214 }
215 };
216
217 static Table _table;
218 public:
219
220 static FunctionType function(Klass* klass) {
221 return _table._function[klass->kind()];
222 }
223 };
224
225 template <typename OopClosureType>
226 typename OopOopIterateBoundedDispatch<OopClosureType>::Table OopOopIterateBoundedDispatch<OopClosureType>::_table;
227
228
229 template <typename OopClosureType>
230 class OopOopIterateBackwardsDispatch {
231 private:
232 typedef void (*FunctionType)(OopClosureType*, oop, Klass*);
233
234 class Table {
235 private:
236 template <typename KlassType, typename T>
237 static void oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* k) {
238 ((KlassType*)k)->KlassType::template oop_oop_iterate_reverse<T>(obj, cl);
239 }
240
241 template <typename KlassType>
242 static void init(OopClosureType* cl, oop obj, Klass* k) {
243 OopOopIterateBackwardsDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
244 }
245
246 template <typename KlassType>
247 void set_init_function() {
248 _function[KlassType::Kind] = &init<KlassType>;
249 }
250
251 template <typename KlassType>
252 void set_resolve_function() {
253 if (UseCompressedOops) {
254 _function[KlassType::Kind] = &oop_oop_iterate_backwards<KlassType, narrowOop>;
255 } else {
256 _function[KlassType::Kind] = &oop_oop_iterate_backwards<KlassType, oop>;
257 }
258 }
259
260 template <typename KlassType>
261 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
262 set_resolve_function<KlassType>();
263 _function[KlassType::Kind](cl, obj, k);
264 }
265
266 public:
267 FunctionType _function[Klass::KLASS_KIND_COUNT];
268
269 Table(){
270 set_init_function<InstanceKlass>();
271 set_init_function<InstanceRefKlass>();
272 set_init_function<InstanceMirrorKlass>();
273 set_init_function<InstanceClassLoaderKlass>();
274 set_init_function<InstanceStackChunkKlass>();
275 set_init_function<ObjArrayKlass>();
276 set_init_function<TypeArrayKlass>();
277 }
278 };
279
280 static Table _table;
281 public:
282
283 static FunctionType function(Klass* klass) {
284 return _table._function[klass->kind()];
285 }
286 };
287
288 template <typename OopClosureType>
289 typename OopOopIterateBackwardsDispatch<OopClosureType>::Table OopOopIterateBackwardsDispatch<OopClosureType>::_table;
290
291
292 template <typename OopClosureType>
293 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass) {
294 OopOopIterateDispatch<OopClosureType>::function(klass)(cl, obj, klass);
295 }
296
297 template <typename OopClosureType>
298 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass, MemRegion mr) {
299 OopOopIterateBoundedDispatch<OopClosureType>::function(klass)(cl, obj, klass, mr);
300 }
301
302 template <typename OopClosureType>
303 void OopIteratorClosureDispatch::oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* klass) {
304 OopOopIterateBackwardsDispatch<OopClosureType>::function(klass)(cl, obj, klass);
305 }
306
307 #endif // SHARE_MEMORY_ITERATOR_INLINE_HPP