1 /*
2 * Copyright (c) 2014, 2024, 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/klass.hpp"
35 #include "oops/instanceKlass.inline.hpp"
36 #include "oops/instanceMirrorKlass.inline.hpp"
37 #include "oops/instanceClassLoaderKlass.inline.hpp"
38 #include "oops/instanceRefKlass.inline.hpp"
39 #include "oops/instanceStackChunkKlass.inline.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 if (cld != nullptr) {
50 // Could be null during early VM bootstrap for archived heap objects whose
51 // class has not yet been loaded by CDS.
52 cld->oops_do(this, _claim);
53 }
54 }
55
56 inline void ClaimMetadataVisitingOopIterateClosure::do_klass(Klass* k) {
57 ClassLoaderData* cld = k->class_loader_data();
58 ClaimMetadataVisitingOopIterateClosure::do_cld(cld);
59 }
60
61 inline void ClaimMetadataVisitingOopIterateClosure::do_nmethod(nmethod* nm) {
62 nm->follow_nmethod(this);
63 }
64
65 inline void ClaimMetadataVisitingOopIterateClosure::do_method(Method* m) {
66 // Mark interpreted frames for class redefinition
67 m->record_gc_epoch();
68 }
69
70 // Dispatch table implementation for *Klass::oop_oop_iterate
71 //
72 // It allows for a single call to do a multi-dispatch to an optimized version
73 // of oop_oop_iterate that statically know all these types:
74 // - OopClosureType : static type give at call site
75 // - Klass* : dynamic to static type through Klass::kind() -> table index
76 // - UseCompressedOops : dynamic to static value determined once
77 //
78 // when users call obj->oop_iterate(&cl).
79 //
80 // oopDesc::oop_iterate() calls OopOopIterateDispatch::function(klass)(cl, obj, klass),
81 // which dispatches to an optimized version of
82 // [Instance, ObjArry, etc]Klass::oop_oop_iterate(oop, OopClosureType)
83 //
84 // OopClosureType :
85 // If OopClosureType has an implementation of do_oop (and do_metadata et.al.),
86 // then the static type of OopClosureType will be used to allow inlining of
87 // do_oop (even though do_oop is virtual). Otherwise, a virtual call will be
88 // used when calling do_oop.
89 //
90 // Klass* :
91 // A table mapping from *Klass::Kind to function is setup. This happens once
92 // when the program starts, when the static _table instance is initialized for
93 // the OopOopIterateDispatch specialized with the OopClosureType.
94 //
95 // UseCompressedOops :
96 // Initially the table is populated with an init function, and not the actual
97 // oop_oop_iterate function. This is done, so that the first time we dispatch
98 // through the init function we check what the value of UseCompressedOops
99 // became, and use that to determine if we should install an optimized
100 // narrowOop version or optimized oop version of oop_oop_iterate. The appropriate
101 // oop_oop_iterate function replaces the init function in the table, and
102 // succeeding calls will jump directly to oop_oop_iterate.
103
104
105 template <typename OopClosureType>
106 class OopOopIterateDispatch : public AllStatic {
107 private:
108 typedef void (*FunctionType)(OopClosureType*, oop, Klass*);
109
110 class Table {
111 private:
112 template <typename KlassType, typename T>
113 static void oop_oop_iterate(OopClosureType* cl, oop obj, Klass* k) {
114 ((KlassType*)k)->KlassType::template oop_oop_iterate<T>(obj, cl);
115 }
116
117 template <typename KlassType>
118 static void init(OopClosureType* cl, oop obj, Klass* k) {
119 OopOopIterateDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
120 }
121
122 template <typename KlassType>
123 void set_init_function() {
124 _function[KlassType::Kind] = &init<KlassType>;
125 }
126
127 template <typename KlassType>
128 void set_resolve_function() {
129 // Size requirement to prevent word tearing
130 // when functions pointers are updated.
131 STATIC_ASSERT(sizeof(_function[0]) == sizeof(void*));
132 if (UseCompressedOops) {
133 _function[KlassType::Kind] = &oop_oop_iterate<KlassType, narrowOop>;
134 } else {
135 _function[KlassType::Kind] = &oop_oop_iterate<KlassType, oop>;
136 }
137 }
138
139 template <typename KlassType>
140 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
141 set_resolve_function<KlassType>();
142 _function[KlassType::Kind](cl, obj, k);
143 }
144
145 public:
146 FunctionType _function[Klass::KLASS_KIND_COUNT];
147
148 Table(){
149 set_init_function<InstanceKlass>();
150 set_init_function<InstanceRefKlass>();
151 set_init_function<InstanceMirrorKlass>();
152 set_init_function<InstanceClassLoaderKlass>();
153 set_init_function<InstanceStackChunkKlass>();
154 set_init_function<ObjArrayKlass>();
155 set_init_function<TypeArrayKlass>();
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<InstanceRefKlass>();
214 set_init_function<InstanceMirrorKlass>();
215 set_init_function<InstanceClassLoaderKlass>();
216 set_init_function<InstanceStackChunkKlass>();
217 set_init_function<ObjArrayKlass>();
218 set_init_function<TypeArrayKlass>();
219 }
220 };
221
222 static Table _table;
223 public:
224
225 static FunctionType function(Klass* klass) {
226 return _table._function[klass->kind()];
227 }
228 };
229
230 template <typename OopClosureType>
231 typename OopOopIterateBoundedDispatch<OopClosureType>::Table OopOopIterateBoundedDispatch<OopClosureType>::_table;
232
233
234 template <typename OopClosureType>
235 class OopOopIterateBackwardsDispatch {
236 private:
237 typedef void (*FunctionType)(OopClosureType*, oop, Klass*);
238
239 class Table {
240 private:
241 template <typename KlassType, typename T>
242 static void oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* k) {
243 ((KlassType*)k)->KlassType::template oop_oop_iterate_reverse<T>(obj, cl);
244 }
245
246 template <typename KlassType>
247 static void init(OopClosureType* cl, oop obj, Klass* k) {
248 OopOopIterateBackwardsDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
249 }
250
251 template <typename KlassType>
252 void set_init_function() {
253 _function[KlassType::Kind] = &init<KlassType>;
254 }
255
256 template <typename KlassType>
257 void set_resolve_function() {
258 if (UseCompressedOops) {
259 _function[KlassType::Kind] = &oop_oop_iterate_backwards<KlassType, narrowOop>;
260 } else {
261 _function[KlassType::Kind] = &oop_oop_iterate_backwards<KlassType, oop>;
262 }
263 }
264
265 template <typename KlassType>
266 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
267 set_resolve_function<KlassType>();
268 _function[KlassType::Kind](cl, obj, k);
269 }
270
271 public:
272 FunctionType _function[Klass::KLASS_KIND_COUNT];
273
274 Table(){
275 set_init_function<InstanceKlass>();
276 set_init_function<InstanceRefKlass>();
277 set_init_function<InstanceMirrorKlass>();
278 set_init_function<InstanceClassLoaderKlass>();
279 set_init_function<InstanceStackChunkKlass>();
280 set_init_function<ObjArrayKlass>();
281 set_init_function<TypeArrayKlass>();
282 }
283 };
284
285 static Table _table;
286 public:
287
288 static FunctionType function(Klass* klass) {
289 return _table._function[klass->kind()];
290 }
291 };
292
293 template <typename OopClosureType>
294 typename OopOopIterateBackwardsDispatch<OopClosureType>::Table OopOopIterateBackwardsDispatch<OopClosureType>::_table;
295
296
297 template <typename OopClosureType>
298 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass) {
299 OopOopIterateDispatch<OopClosureType>::function(klass)(cl, obj, klass);
300 }
301
302 template <typename OopClosureType>
303 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass, MemRegion mr) {
304 OopOopIterateBoundedDispatch<OopClosureType>::function(klass)(cl, obj, klass, mr);
305 }
306
307 template <typename OopClosureType>
308 void OopIteratorClosureDispatch::oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* klass) {
309 OopOopIterateBackwardsDispatch<OopClosureType>::function(klass)(cl, obj, klass);
310 }
311
312 #endif // SHARE_MEMORY_ITERATOR_INLINE_HPP