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/flatArrayKlass.inline.hpp"
35 #include "oops/instanceClassLoaderKlass.inline.hpp"
36 #include "oops/instanceKlass.inline.hpp"
37 #include "oops/instanceMirrorKlass.inline.hpp"
38 #include "oops/instanceRefKlass.inline.hpp"
39 #include "oops/instanceStackChunkKlass.inline.hpp"
40 #include "oops/klass.hpp"
41 #include "oops/objArrayKlass.inline.hpp"
42 #include "oops/refArrayKlass.inline.hpp"
43 #include "oops/typeArrayKlass.inline.hpp"
44 #include "utilities/debug.hpp"
45
46 // Defaults to strong claiming.
47 inline MetadataVisitingOopIterateClosure::MetadataVisitingOopIterateClosure(ReferenceDiscoverer* rd) :
48 ClaimMetadataVisitingOopIterateClosure(ClassLoaderData::_claim_strong, rd) {}
49
50 inline void ClaimMetadataVisitingOopIterateClosure::do_cld(ClassLoaderData* cld) {
51 cld->oops_do(this, _claim);
52 }
53
54 inline void ClaimMetadataVisitingOopIterateClosure::do_klass(Klass* k) {
55 ClaimMetadataVisitingOopIterateClosure::do_cld(k->class_loader_data());
56 }
57
58 inline void ClaimMetadataVisitingOopIterateClosure::do_nmethod(nmethod* nm) {
59 nm->follow_nmethod(this);
60 }
61
62 inline void ClaimMetadataVisitingOopIterateClosure::do_method(Method* m) {
63 // Mark interpreted frames for class redefinition
64 m->record_gc_epoch();
65 }
66
67 // Dispatch table implementation for *Klass::oop_oop_iterate
68 //
69 // It allows for a single call to do a multi-dispatch to an optimized version
70 // of oop_oop_iterate that statically know all these types:
71 // - OopClosureType : static type give at call site
72 // - Klass* : dynamic to static type through Klass::kind() -> table index
73 // - UseCompressedOops : dynamic to static value determined once
74 //
75 // when users call obj->oop_iterate(&cl).
76 //
77 // oopDesc::oop_iterate() calls OopOopIterateDispatch::function(klass)(cl, obj, klass),
78 // which dispatches to an optimized version of
79 // [Instance, ObjArry, etc]Klass::oop_oop_iterate(oop, OopClosureType)
80 //
81 // OopClosureType :
82 // If OopClosureType has an implementation of do_oop (and do_metadata et.al.),
83 // then the static type of OopClosureType will be used to allow inlining of
84 // do_oop (even though do_oop is virtual). Otherwise, a virtual call will be
85 // used when calling do_oop.
86 //
87 // Klass* :
88 // A table mapping from *Klass::Kind to function is setup. This happens once
89 // when the program starts, when the static _table instance is initialized for
90 // the OopOopIterateDispatch specialized with the OopClosureType.
91 //
92 // UseCompressedOops :
93 // Initially the table is populated with an init function, and not the actual
94 // oop_oop_iterate function. This is done, so that the first time we dispatch
95 // through the init function we check what the value of UseCompressedOops
96 // became, and use that to determine if we should install an optimized
97 // narrowOop version or optimized oop version of oop_oop_iterate. The appropriate
98 // oop_oop_iterate function replaces the init function in the table, and
99 // succeeding calls will jump directly to oop_oop_iterate.
100
101
102 template <typename OopClosureType>
103 class OopOopIterateDispatch : public AllStatic {
104 private:
105 typedef void (*FunctionType)(OopClosureType*, oop, Klass*);
106
107 class Table {
108 private:
109 template <typename KlassType, typename T>
110 static void oop_oop_iterate(OopClosureType* cl, oop obj, Klass* k) {
111 ((KlassType*)k)->KlassType::template oop_oop_iterate<T>(obj, cl);
112 }
113
114 template <typename KlassType>
115 static void init(OopClosureType* cl, oop obj, Klass* k) {
116 OopOopIterateDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
117 }
118
119 template <typename KlassType>
120 void set_init_function() {
121 _function[KlassType::Kind] = &init<KlassType>;
122 }
123
124 template <typename KlassType>
125 void set_resolve_function() {
126 // Size requirement to prevent word tearing
127 // when functions pointers are updated.
128 STATIC_ASSERT(sizeof(_function[0]) == sizeof(void*));
129 if (UseCompressedOops) {
130 _function[KlassType::Kind] = &oop_oop_iterate<KlassType, narrowOop>;
131 } else {
132 _function[KlassType::Kind] = &oop_oop_iterate<KlassType, oop>;
133 }
134 }
135
136 template <typename KlassType>
137 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
138 set_resolve_function<KlassType>();
139 _function[KlassType::Kind](cl, obj, k);
140 }
141
142 public:
143 FunctionType _function[Klass::KLASS_KIND_COUNT];
144
145 Table(){
146 set_init_function<InstanceKlass>();
147 set_init_function<InlineKlass>();
148 set_init_function<InstanceRefKlass>();
149 set_init_function<InstanceMirrorKlass>();
150 set_init_function<InstanceClassLoaderKlass>();
151 set_init_function<InstanceStackChunkKlass>();
152 set_init_function<ObjArrayKlass>();
153 set_init_function<TypeArrayKlass>();
154 set_init_function<FlatArrayKlass>();
155 set_init_function<RefArrayKlass>();
156 }
157 };
158
159 static Table _table;
160 public:
161
162 static FunctionType function(Klass* klass) {
163 return _table._function[klass->kind()];
164 }
165 };
166
167 template <typename OopClosureType>
168 typename OopOopIterateDispatch<OopClosureType>::Table OopOopIterateDispatch<OopClosureType>::_table;
169
170
171 template <typename OopClosureType>
172 class OopOopIterateBoundedDispatch {
173 private:
174 typedef void (*FunctionType)(OopClosureType*, oop, Klass*, MemRegion);
175
176 class Table {
177 private:
178 template <typename KlassType, typename T>
179 static void oop_oop_iterate_bounded(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
180 ((KlassType*)k)->KlassType::template oop_oop_iterate_bounded<T>(obj, cl, mr);
181 }
182
183 template <typename KlassType>
184 static void init(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
185 OopOopIterateBoundedDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k, mr);
186 }
187
188 template <typename KlassType>
189 void set_init_function() {
190 _function[KlassType::Kind] = &init<KlassType>;
191 }
192
193 template <typename KlassType>
194 void set_resolve_function() {
195 if (UseCompressedOops) {
196 _function[KlassType::Kind] = &oop_oop_iterate_bounded<KlassType, narrowOop>;
197 } else {
198 _function[KlassType::Kind] = &oop_oop_iterate_bounded<KlassType, oop>;
199 }
200 }
201
202 template <typename KlassType>
203 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
204 set_resolve_function<KlassType>();
205 _function[KlassType::Kind](cl, obj, k, mr);
206 }
207
208 public:
209 FunctionType _function[Klass::KLASS_KIND_COUNT];
210
211 Table(){
212 set_init_function<InstanceKlass>();
213 set_init_function<InlineKlass>();
214 set_init_function<InstanceRefKlass>();
215 set_init_function<InstanceMirrorKlass>();
216 set_init_function<InstanceClassLoaderKlass>();
217 set_init_function<InstanceStackChunkKlass>();
218 set_init_function<ObjArrayKlass>();
219 set_init_function<TypeArrayKlass>();
220 set_init_function<FlatArrayKlass>();
221 set_init_function<RefArrayKlass>();
222 }
223 };
224
225 static Table _table;
226 public:
227
228 static FunctionType function(Klass* klass) {
229 return _table._function[klass->kind()];
230 }
231 };
232
233 template <typename OopClosureType>
234 typename OopOopIterateBoundedDispatch<OopClosureType>::Table OopOopIterateBoundedDispatch<OopClosureType>::_table;
235
236
237 template <typename OopClosureType>
238 class OopOopIterateBackwardsDispatch {
239 private:
240 typedef void (*FunctionType)(OopClosureType*, oop, Klass*);
241
242 class Table {
243 private:
244 template <typename KlassType, typename T>
245 static void oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* k) {
246 ((KlassType*)k)->KlassType::template oop_oop_iterate_reverse<T>(obj, cl);
247 }
248
249 template <typename KlassType>
250 static void init(OopClosureType* cl, oop obj, Klass* k) {
251 OopOopIterateBackwardsDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
252 }
253
254 template <typename KlassType>
255 void set_init_function() {
256 _function[KlassType::Kind] = &init<KlassType>;
257 }
258
259 template <typename KlassType>
260 void set_resolve_function() {
261 if (UseCompressedOops) {
262 _function[KlassType::Kind] = &oop_oop_iterate_backwards<KlassType, narrowOop>;
263 } else {
264 _function[KlassType::Kind] = &oop_oop_iterate_backwards<KlassType, oop>;
265 }
266 }
267
268 template <typename KlassType>
269 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
270 set_resolve_function<KlassType>();
271 _function[KlassType::Kind](cl, obj, k);
272 }
273
274 public:
275 FunctionType _function[Klass::KLASS_KIND_COUNT];
276
277 Table(){
278 set_init_function<InstanceKlass>();
279 set_init_function<InlineKlass>();
280 set_init_function<InstanceRefKlass>();
281 set_init_function<InstanceMirrorKlass>();
282 set_init_function<InstanceClassLoaderKlass>();
283 set_init_function<InstanceStackChunkKlass>();
284 set_init_function<ObjArrayKlass>();
285 set_init_function<TypeArrayKlass>();
286 set_init_function<FlatArrayKlass>();
287 set_init_function<RefArrayKlass>();
288 }
289 };
290
291 static Table _table;
292 public:
293
294 static FunctionType function(Klass* klass) {
295 return _table._function[klass->kind()];
296 }
297 };
298
299 template <typename OopClosureType>
300 typename OopOopIterateBackwardsDispatch<OopClosureType>::Table OopOopIterateBackwardsDispatch<OopClosureType>::_table;
301
302
303 template <typename OopClosureType>
304 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass) {
305 OopOopIterateDispatch<OopClosureType>::function(klass)(cl, obj, klass);
306 }
307
308 template <typename OopClosureType>
309 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass, MemRegion mr) {
310 OopOopIterateBoundedDispatch<OopClosureType>::function(klass)(cl, obj, klass, mr);
311 }
312
313 template <typename OopClosureType>
314 void OopIteratorClosureDispatch::oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* klass) {
315 OopOopIterateBackwardsDispatch<OopClosureType>::function(klass)(cl, obj, klass);
316 }
317
318 #endif // SHARE_MEMORY_ITERATOR_INLINE_HPP