1 /*
2 * Copyright (c) 2017, 2018, 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.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_ACCESSBACKEND_HPP
26 #define SHARE_VM_RUNTIME_ACCESSBACKEND_HPP
27
28 #include "metaprogramming/conditional.hpp"
29 #include "metaprogramming/enableIf.hpp"
30 #include "metaprogramming/integralConstant.hpp"
31 #include "metaprogramming/isSame.hpp"
32 #include "utilities/debug.hpp"
33 #include "utilities/globalDefinitions.hpp"
34
35 // This metafunction returns either oop or narrowOop depending on whether
36 // an access needs to use compressed oops or not.
37 template <DecoratorSet decorators>
38 struct HeapOopType: AllStatic {
39 static const bool needs_oop_compress = HasDecorator<decorators, INTERNAL_CONVERT_COMPRESSED_OOP>::value &&
40 HasDecorator<decorators, INTERNAL_RT_USE_COMPRESSED_OOPS>::value;
41 typedef typename Conditional<needs_oop_compress, narrowOop, oop>::type type;
42 };
43
44 namespace AccessInternal {
45 enum BarrierType {
46 BARRIER_STORE,
47 BARRIER_STORE_AT,
48 BARRIER_LOAD,
49 BARRIER_LOAD_AT,
50 BARRIER_ATOMIC_CMPXCHG,
51 BARRIER_ATOMIC_CMPXCHG_AT,
52 BARRIER_ATOMIC_XCHG,
53 BARRIER_ATOMIC_XCHG_AT,
54 BARRIER_ARRAYCOPY,
55 BARRIER_CLONE,
56 BARRIER_RESOLVE
57 };
58
59 template <DecoratorSet decorators, typename T>
60 struct MustConvertCompressedOop: public IntegralConstant<bool,
61 HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value &&
62 IsSame<typename HeapOopType<decorators>::type, narrowOop>::value &&
63 IsSame<T, oop>::value> {};
64
65 // This metafunction returns an appropriate oop type if the value is oop-like
66 // and otherwise returns the same type T.
67 template <DecoratorSet decorators, typename T>
68 struct EncodedType: AllStatic {
69 typedef typename Conditional<
70 HasDecorator<decorators, INTERNAL_VALUE_IS_OOP>::value,
71 typename HeapOopType<decorators>::type, T>::type type;
72 };
73
74 template <DecoratorSet decorators>
75 inline typename HeapOopType<decorators>::type*
76 oop_field_addr(oop base, ptrdiff_t byte_offset) {
77 return reinterpret_cast<typename HeapOopType<decorators>::type*>(
78 reinterpret_cast<intptr_t>((void*)base) + byte_offset);
79 }
80
81 // This metafunction returns whether it is possible for a type T to require
82 // locking to support wide atomics or not.
83 template <typename T>
84 #ifdef SUPPORTS_NATIVE_CX8
85 struct PossiblyLockedAccess: public IntegralConstant<bool, false> {};
86 #else
87 struct PossiblyLockedAccess: public IntegralConstant<bool, (sizeof(T) > 4)> {};
88 #endif
89
90 template <DecoratorSet decorators, typename T>
91 struct AccessFunctionTypes {
92 typedef T (*load_at_func_t)(oop base, ptrdiff_t offset);
93 typedef void (*store_at_func_t)(oop base, ptrdiff_t offset, T value);
94 typedef T (*atomic_cmpxchg_at_func_t)(T new_value, oop base, ptrdiff_t offset, T compare_value);
95 typedef T (*atomic_xchg_at_func_t)(T new_value, oop base, ptrdiff_t offset);
96
97 typedef T (*load_func_t)(void* addr);
98 typedef void (*store_func_t)(void* addr, T value);
99 typedef T (*atomic_cmpxchg_func_t)(T new_value, void* addr, T compare_value);
100 typedef T (*atomic_xchg_func_t)(T new_value, void* addr);
101
102 typedef bool (*arraycopy_func_t)(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length);
103 typedef void (*clone_func_t)(oop src, oop dst, size_t size);
104 typedef oop (*resolve_func_t)(oop obj);
105 };
106
107 template <DecoratorSet decorators>
108 struct AccessFunctionTypes<decorators, void> {
109 typedef bool (*arraycopy_func_t)(arrayOop src_obj, arrayOop dst_obj, void* src, void* dst, size_t length);
110 };
111
112 template <DecoratorSet decorators, typename T, BarrierType barrier> struct AccessFunction {};
113
114 #define ACCESS_GENERATE_ACCESS_FUNCTION(bt, func) \
115 template <DecoratorSet decorators, typename T> \
116 struct AccessFunction<decorators, T, bt>: AllStatic{ \
117 typedef typename AccessFunctionTypes<decorators, T>::func type; \
118 }
119 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_STORE, store_func_t);
120 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_STORE_AT, store_at_func_t);
121 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_LOAD, load_func_t);
122 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_LOAD_AT, load_at_func_t);
123 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_ATOMIC_CMPXCHG, atomic_cmpxchg_func_t);
124 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_ATOMIC_CMPXCHG_AT, atomic_cmpxchg_at_func_t);
125 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_ATOMIC_XCHG, atomic_xchg_func_t);
126 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_ATOMIC_XCHG_AT, atomic_xchg_at_func_t);
127 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_ARRAYCOPY, arraycopy_func_t);
128 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_CLONE, clone_func_t);
129 ACCESS_GENERATE_ACCESS_FUNCTION(BARRIER_RESOLVE, resolve_func_t);
130 #undef ACCESS_GENERATE_ACCESS_FUNCTION
131
132 template <DecoratorSet decorators, typename T, BarrierType barrier_type>
133 typename AccessFunction<decorators, T, barrier_type>::type resolve_barrier();
134
135 template <DecoratorSet decorators, typename T, BarrierType barrier_type>
136 typename AccessFunction<decorators, T, barrier_type>::type resolve_oop_barrier();
137
138 class AccessLocker {
139 public:
140 AccessLocker();
141 ~AccessLocker();
142 };
143 bool wide_atomic_needs_locking();
144
145 void* field_addr(oop base, ptrdiff_t offset);
146
147 // Forward calls to Copy:: in the cpp file to reduce dependencies and allow
148 // faster build times, given how frequently included access is.
149 void arraycopy_arrayof_conjoint_oops(void* src, void* dst, size_t length);
150 void arraycopy_conjoint_oops(oop* src, oop* dst, size_t length);
151 void arraycopy_conjoint_oops(narrowOop* src, narrowOop* dst, size_t length);
152
153 void arraycopy_disjoint_words(void* src, void* dst, size_t length);
154 void arraycopy_disjoint_words_atomic(void* src, void* dst, size_t length);
155
156 template<typename T>
157 void arraycopy_conjoint(T* src, T* dst, size_t length);
158 template<typename T>
159 void arraycopy_arrayof_conjoint(T* src, T* dst, size_t length);
160 template<typename T>
161 void arraycopy_conjoint_atomic(T* src, T* dst, size_t length);
162 }
163
164 // This mask specifies what decorators are relevant for raw accesses. When passing
165 // accesses to the raw layer, irrelevant decorators are removed.
166 const DecoratorSet RAW_DECORATOR_MASK = INTERNAL_DECORATOR_MASK | MO_DECORATOR_MASK |
167 ARRAYCOPY_DECORATOR_MASK | OOP_DECORATOR_MASK;
168
169 // The RawAccessBarrier performs raw accesses with additional knowledge of
170 // memory ordering, so that OrderAccess/Atomic is called when necessary.
171 // It additionally handles compressed oops, and hence is not completely "raw"
172 // strictly speaking.
173 template <DecoratorSet decorators>
174 class RawAccessBarrier: public AllStatic {
175 protected:
176 static inline void* field_addr(oop base, ptrdiff_t byte_offset) {
177 return AccessInternal::field_addr(base, byte_offset);
178 }
179
180 protected:
181 // Only encode if INTERNAL_VALUE_IS_OOP
182 template <DecoratorSet idecorators, typename T>
183 static inline typename EnableIf<
184 AccessInternal::MustConvertCompressedOop<idecorators, T>::value,
185 typename HeapOopType<idecorators>::type>::type
186 encode_internal(T value);
187
188 template <DecoratorSet idecorators, typename T>
189 static inline typename EnableIf<
190 !AccessInternal::MustConvertCompressedOop<idecorators, T>::value, T>::type
191 encode_internal(T value) {
192 return value;
193 }
194
195 template <typename T>
196 static inline typename AccessInternal::EncodedType<decorators, T>::type
197 encode(T value) {
198 return encode_internal<decorators, T>(value);
199 }
200
201 // Only decode if INTERNAL_VALUE_IS_OOP
202 template <DecoratorSet idecorators, typename T>
203 static inline typename EnableIf<
204 AccessInternal::MustConvertCompressedOop<idecorators, T>::value, T>::type
205 decode_internal(typename HeapOopType<idecorators>::type value);
206
207 template <DecoratorSet idecorators, typename T>
208 static inline typename EnableIf<
209 !AccessInternal::MustConvertCompressedOop<idecorators, T>::value, T>::type
210 decode_internal(T value) {
211 return value;
212 }
213
214 template <typename T>
215 static inline T decode(typename AccessInternal::EncodedType<decorators, T>::type value) {
216 return decode_internal<decorators, T>(value);
217 }
218
219 protected:
220 template <DecoratorSet ds, typename T>
221 static typename EnableIf<
222 HasDecorator<ds, MO_SEQ_CST>::value, T>::type
223 load_internal(void* addr);
224
225 template <DecoratorSet ds, typename T>
226 static typename EnableIf<
227 HasDecorator<ds, MO_ACQUIRE>::value, T>::type
228 load_internal(void* addr);
229
230 template <DecoratorSet ds, typename T>
231 static typename EnableIf<
232 HasDecorator<ds, MO_RELAXED>::value, T>::type
233 load_internal(void* addr);
234
235 template <DecoratorSet ds, typename T>
236 static inline typename EnableIf<
237 HasDecorator<ds, MO_VOLATILE>::value, T>::type
238 load_internal(void* addr) {
239 return *reinterpret_cast<const volatile T*>(addr);
240 }
241
242 template <DecoratorSet ds, typename T>
243 static inline typename EnableIf<
244 HasDecorator<ds, MO_UNORDERED>::value, T>::type
245 load_internal(void* addr) {
246 return *reinterpret_cast<const T*>(addr);
247 }
248
249 template <DecoratorSet ds, typename T>
250 static typename EnableIf<
251 HasDecorator<ds, MO_SEQ_CST>::value>::type
252 store_internal(void* addr, T value);
253
254 template <DecoratorSet ds, typename T>
255 static typename EnableIf<
256 HasDecorator<ds, MO_RELEASE>::value>::type
257 store_internal(void* addr, T value);
258
259 template <DecoratorSet ds, typename T>
260 static typename EnableIf<
261 HasDecorator<ds, MO_RELAXED>::value>::type
262 store_internal(void* addr, T value);
263
264 template <DecoratorSet ds, typename T>
265 static inline typename EnableIf<
266 HasDecorator<ds, MO_VOLATILE>::value>::type
267 store_internal(void* addr, T value) {
268 (void)const_cast<T&>(*reinterpret_cast<volatile T*>(addr) = value);
269 }
270
271 template <DecoratorSet ds, typename T>
272 static inline typename EnableIf<
273 HasDecorator<ds, MO_UNORDERED>::value>::type
274 store_internal(void* addr, T value) {
275 *reinterpret_cast<T*>(addr) = value;
276 }
277
278 template <DecoratorSet ds, typename T>
279 static typename EnableIf<
280 HasDecorator<ds, MO_SEQ_CST>::value, T>::type
281 atomic_cmpxchg_internal(T new_value, void* addr, T compare_value);
282
283 template <DecoratorSet ds, typename T>
284 static typename EnableIf<
285 HasDecorator<ds, MO_RELAXED>::value, T>::type
286 atomic_cmpxchg_internal(T new_value, void* addr, T compare_value);
287
288 template <DecoratorSet ds, typename T>
289 static typename EnableIf<
290 HasDecorator<ds, MO_SEQ_CST>::value, T>::type
291 atomic_xchg_internal(T new_value, void* addr);
292
293 // The following *_locked mechanisms serve the purpose of handling atomic operations
294 // that are larger than a machine can handle, and then possibly opt for using
295 // a slower path using a mutex to perform the operation.
296
297 template <DecoratorSet ds, typename T>
298 static inline typename EnableIf<
299 !AccessInternal::PossiblyLockedAccess<T>::value, T>::type
300 atomic_cmpxchg_maybe_locked(T new_value, void* addr, T compare_value) {
301 return atomic_cmpxchg_internal<ds>(new_value, addr, compare_value);
302 }
303
304 template <DecoratorSet ds, typename T>
305 static typename EnableIf<
306 AccessInternal::PossiblyLockedAccess<T>::value, T>::type
307 atomic_cmpxchg_maybe_locked(T new_value, void* addr, T compare_value);
308
309 template <DecoratorSet ds, typename T>
310 static inline typename EnableIf<
311 !AccessInternal::PossiblyLockedAccess<T>::value, T>::type
312 atomic_xchg_maybe_locked(T new_value, void* addr) {
313 return atomic_xchg_internal<ds>(new_value, addr);
314 }
315
316 template <DecoratorSet ds, typename T>
317 static typename EnableIf<
318 AccessInternal::PossiblyLockedAccess<T>::value, T>::type
319 atomic_xchg_maybe_locked(T new_value, void* addr);
320
321 public:
322 template <typename T>
323 static inline void store(void* addr, T value) {
324 store_internal<decorators>(addr, value);
325 }
326
327 template <typename T>
328 static inline T load(void* addr) {
329 return load_internal<decorators, T>(addr);
330 }
331
332 template <typename T>
333 static inline T atomic_cmpxchg(T new_value, void* addr, T compare_value) {
334 return atomic_cmpxchg_maybe_locked<decorators>(new_value, addr, compare_value);
335 }
336
337 template <typename T>
338 static inline T atomic_xchg(T new_value, void* addr) {
339 return atomic_xchg_maybe_locked<decorators>(new_value, addr);
340 }
341
342 template <typename T>
343 static bool arraycopy(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length);
344
345 template <typename T>
346 static void oop_store(void* addr, T value);
347 template <typename T>
348 static void oop_store_at(oop base, ptrdiff_t offset, T value);
349
350 template <typename T>
351 static T oop_load(void* addr);
352 template <typename T>
353 static T oop_load_at(oop base, ptrdiff_t offset);
354
355 template <typename T>
356 static T oop_atomic_cmpxchg(T new_value, void* addr, T compare_value);
357 template <typename T>
358 static T oop_atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value);
359
360 template <typename T>
361 static T oop_atomic_xchg(T new_value, void* addr);
362 template <typename T>
363 static T oop_atomic_xchg_at(T new_value, oop base, ptrdiff_t offset);
364
365 template <typename T>
366 static void store_at(oop base, ptrdiff_t offset, T value) {
367 store(field_addr(base, offset), value);
368 }
369
370 template <typename T>
371 static T load_at(oop base, ptrdiff_t offset) {
372 return load<T>(field_addr(base, offset));
373 }
374
375 template <typename T>
376 static T atomic_cmpxchg_at(T new_value, oop base, ptrdiff_t offset, T compare_value) {
377 return atomic_cmpxchg(new_value, field_addr(base, offset), compare_value);
378 }
379
380 template <typename T>
381 static T atomic_xchg_at(T new_value, oop base, ptrdiff_t offset) {
382 return atomic_xchg(new_value, field_addr(base, offset));
383 }
384
385 template <typename T>
386 static bool oop_arraycopy(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length);
387 static bool oop_arraycopy(arrayOop src_obj, arrayOop dst_obj, HeapWord* src, HeapWord* dst, size_t length);
388
389 static void clone(oop src, oop dst, size_t size);
390
391 static oop resolve(oop obj) { return obj; }
392 };
393
394 #endif // SHARE_VM_RUNTIME_ACCESSBACKEND_HPP