1 /*****************************************************************************
3 *****************************************************************************
4 * Copyright (C) 2010 RĂ©mi Denis-Courmont
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU Lesser General Public License as published by
8 * the Free Software Foundation; either version 2.1 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
26 * Atomic operations do not require locking, but they are not very powerful.
29 # if !defined (__cplusplus) && (__STDC_VERSION__ >= 201112L) \
30 && !defined (__STDC_NO_ATOMICS__)
32 /*** Native C11 atomics ***/
33 # include <stdatomic.h>
37 # define ATOMIC_FLAG_INIT false
39 # define ATOMIC_VAR_INIT(value) (value)
41 # define atomic_init(obj, value) \
42 do { *(obj) = (value); } while(0)
44 # define kill_dependency(y) \
47 # define atomic_thread_fence(order) \
50 # define atomic_signal_fence(order) \
53 # define atomic_is_lock_free(obj) \
56 /* In principles, __sync_*() only supports int, long and long long and their
57 * unsigned equivalents, i.e. 4-bytes and 8-bytes types, although GCC also
58 * supports 1 and 2-bytes types. Some non-x86 architectures do not support
59 * 8-byte atomic types (or not efficiently). */
60 typedef bool atomic_flag;
61 typedef bool atomic_bool;
62 typedef char atomic_char;
63 typedef signed char atomic_schar;
64 typedef unsigned char atomic_uchar;
65 typedef short atomic_short;
66 typedef unsigned short atomic_ushort;
67 typedef int atomic_int;
68 typedef unsigned int atomic_uint;
69 typedef long atomic_long;
70 typedef unsigned long atomic_ulong;
71 typedef long long atomic_llong;
72 typedef unsigned long long atomic_ullong;
73 //typedef char16_t atomic_char16_t;
74 //typedef char32_t atomic_char32_t;
75 typedef wchar_t atomic_wchar_t;
76 typedef int_least8_t atomic_int_least8_t;
77 typedef uint_least8_t atomic_uint_least8_t;
78 typedef int_least16_t atomic_int_least16_t;
79 typedef uint_least16_t atomic_uint_least16_t;
80 typedef int_least32_t atomic_int_least32_t;
81 typedef uint_least32_t atomic_uint_least32_t;
82 typedef int_least64_t atomic_int_least64_t;
83 typedef uint_least64_t atomic_uint_least64_t;
84 typedef int_fast8_t atomic_int_fast8_t;
85 typedef uint_fast8_t atomic_uint_fast8_t;
86 typedef int_fast16_t atomic_int_fast16_t;
87 typedef uint_fast16_t atomic_uint_fast16_t;
88 typedef int_fast32_t atomic_int_fast32_t;
89 typedef uint_fast32_t atomic_uint_fast32_t;
90 typedef int_fast64_t atomic_int_fast64_t;
91 typedef uint_fast64_t atomic_uint_fast64_t;
92 typedef intptr_t atomic_intptr_t;
93 typedef uintptr_t atomic_uintptr_t;
94 typedef size_t atomic_size_t;
95 typedef ptrdiff_t atomic_ptrdiff_t;
96 typedef intmax_t atomic_intmax_t;
97 typedef uintmax_t atomic_uintmax_t;
99 # if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) || (defined (__clang__) && (defined (__x86_64__) || defined (__i386__)))
101 /*** Intel/GCC atomics ***/
103 # define atomic_store(object,desired) \
105 *(object) = (desired); \
106 __sync_synchronize(); \
109 # define atomic_store_explicit(object,desired,order) \
110 atomic_store(object,desired)
112 # define atomic_load(object) \
113 (__sync_synchronize(), *(object))
115 # define atomic_load_explicit(object,order) \
118 # define atomic_exchange(object,desired) \
120 typeof (object) _obj = (object); \
121 typeof (*object) _old; \
123 _old = atomic_load(_obj); \
124 while (!__sync_bool_compare_and_swap(_obj, _old, (desired))); \
128 # define atomic_exchange_explicit(object,desired,order) \
129 atomic_exchange(object,desired)
131 # define atomic_compare_exchange(object,expected,desired) \
133 typeof (object) _exp = (expected); \
134 typeof (*object) _old = *_exp; \
135 *_exp = __sync_val_compare_and_swap((object), _old, (desired)); \
139 # define atomic_compare_exchange_strong(object,expected,desired) \
140 atomic_compare_exchange(object, expected, desired)
142 # define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
143 atomic_compare_exchange_strong(object, expected, desired)
145 # define atomic_compare_exchange_weak(object,expected,desired) \
146 atomic_compare_exchange(object, expected, desired)
148 # define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
149 atomic_compare_exchange_weak(object, expected, desired)
151 # define atomic_fetch_add(object,operand) \
152 __sync_fetch_and_add(object, operand)
154 # define atomic_fetch_add_explicit(object,operand,order) \
155 atomic_fetch_add(object,operand)
157 # define atomic_fetch_sub(object,operand) \
158 __sync_fetch_and_sub(object, operand)
160 # define atomic_fetch_sub_explicit(object,operand,order) \
161 atomic_fetch_sub(object,operand)
163 # define atomic_fetch_or(object,operand) \
164 __sync_fetch_and_or(object, operand)
166 # define atomic_fetch_or_explicit(object,operand,order) \
167 atomic_fetch_or(object,operand)
169 # define atomic_fetch_xor(object,operand) \
170 __sync_fetch_and_sub(object, operand)
172 # define atomic_fetch_xor_explicit(object,operand,order) \
173 atomic_fetch_sub(object,operand)
175 # define atomic_fetch_and(object,operand) \
176 __sync_fetch_and_and(object, operand)
178 # define atomic_fetch_and_explicit(object,operand,order) \
179 atomic_fetch_and(object,operand)
181 # define atomic_flag_test_and_set(object) \
182 atomic_exchange(object, true)
184 # define atomic_flag_test_and_set_explicit(object,order) \
185 atomic_flag_test_and_set(object)
187 # define atomic_flag_clear(object) \
188 atomic_store(object, false)
190 # define atomic_flag_clear_explicit(object,order) \
191 atomic_flag_clear(object)
193 # elif defined (__GNUC__)
197 # define atomic_store(object,desired) \
199 typeof (object) _obj = (object); \
200 typeof (*object) _des = (desired); \
201 vlc_global_lock(VLC_ATOMIC_MUTEX); \
203 vlc_global_unlock(VLC_ATOMIC_MUTEX); \
205 # define atomic_store_explicit(object,desired,order) \
206 atomic_store(object,desired)
208 # define atomic_load(object) \
210 typeof (object) _obj = (object); \
211 typeof (*object) _old; \
212 vlc_global_lock(VLC_ATOMIC_MUTEX); \
214 vlc_global_unlock(VLC_ATOMIC_MUTEX); \
217 # define atomic_load_explicit(object,order) \
220 # define atomic_exchange(object,desired) \
222 typeof (object) _obj = (object); \
223 typeof (*object) _des = (desired); \
224 typeof (*object) _old; \
225 vlc_global_lock(VLC_ATOMIC_MUTEX); \
228 vlc_global_unlock(VLC_ATOMIC_MUTEX); \
231 # define atomic_exchange_explicit(object,desired,order) \
232 atomic_exchange(object,desired)
234 # define atomic_compare_exchange_strong(object,expected,desired) \
236 typeof (object) _obj = (object); \
237 typeof (object) _exp = (expected); \
238 typeof (*object) _des = (desired); \
240 vlc_global_lock(VLC_ATOMIC_MUTEX); \
241 ret = *_obj == *_exp; \
246 vlc_global_unlock(VLC_ATOMIC_MUTEX); \
249 # define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
250 atomic_compare_exchange_strong(object, expected, desired)
251 # define atomic_compare_exchange_weak(object,expected,desired) \
252 atomic_compare_exchange_strong(object, expected, desired)
253 # define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
254 atomic_compare_exchange_weak(object, expected, desired)
256 # define atomic_fetch_OP(object,desired,op) \
258 typeof (object) _obj = (object); \
259 typeof (*object) _des = (desired); \
260 typeof (*object) _old; \
261 vlc_global_lock(VLC_ATOMIC_MUTEX); \
263 *_obj = (*_obj) op (_des); \
264 vlc_global_unlock(VLC_ATOMIC_MUTEX); \
268 # define atomic_fetch_add(object,operand) \
269 atomic_fetch_OP(object,operand,+)
270 # define atomic_fetch_add_explicit(object,operand,order) \
271 atomic_fetch_add(object,operand)
273 # define atomic_fetch_sub(object,operand) \
274 atomic_fetch_OP(object,operand,-)
275 # define atomic_fetch_sub_explicit(object,operand,order) \
276 atomic_fetch_sub(object,operand)
278 # define atomic_fetch_or(object,operand) \
279 atomic_fetch_OP(object,operand,|)
280 # define atomic_fetch_or_explicit(object,operand,order) \
281 atomic_fetch_or(object,operand)
283 # define atomic_fetch_xor(object,operand) \
284 atomic_fetch_OP(object,operand,^)
285 # define atomic_fetch_xor_explicit(object,operand,order) \
286 atomic_fetch_sub(object,operand)
288 # define atomic_fetch_and(object,operand) \
289 atomic_fetch_OP(object,operand,&)
290 # define atomic_fetch_and_explicit(object,operand,order) \
291 atomic_fetch_and(object,operand)
293 # define atomic_flag_test_and_set(object) \
294 atomic_exchange(object, true)
296 # define atomic_flag_test_and_set_explicit(object,order) \
297 atomic_flag_test_and_set(object)
299 # define atomic_flag_clear(object) \
300 atomic_store(object, false)
302 # define atomic_flag_clear_explicit(object,order) \
303 atomic_flag_clear(object)
305 # elif defined (_MSC_VER)
307 /*** Use the Interlocked API. ***/
309 /* Define macros in order to dispatch to the correct function depending on the type.
310 Several ranges are need because some operations are not implemented for all types. */
311 # define atomic_type_dispatch_32_64(operation, object, ...) \
312 (sizeof(*object) == 4 ? operation(object, __VA_ARGS__) : \
313 sizeof(*object) == 8 ? operation##64(object, __VA_ARGS__) : \
316 # define atomic_type_dispatch_16_64(operation, object, ...) \
317 (sizeof(*object) == 2 ? operation##16(object, __VA_ARGS__) : \
318 atomic_type_dispatch_32_64(operation, object, __VA_ARGS__))
320 # define atomic_type_dispatch_8_64(operation, object, ...) \
321 (sizeof(*object) == 1 ? operation##8(object, __VA_ARGS__) : \
322 atomic_type_dispatch_16_64(operation, object, __VA_ARGS__))
324 # define atomic_store(object,desired) \
325 atomic_type_dispatch_8_64(InterlockedExchange, object, desired)
326 # define atomic_store_explicit(object,desired,order) \
327 atomic_store(object, desired)
329 # define atomic_load(object) \
330 atomic_type_dispatch_16_64(InterlockedCompareExchange, object, 0, 0)
331 # define atomic_load_explicit(object,order) \
334 # define atomic_exchange(object,desired) \
335 atomic_type_dispatch_8_64(InterlockedExchange, object, desired)
336 # define atomic_exchange_explicit(object,desired,order) \
337 atomic_exchange(object, desired)
339 # define atomic_compare_exchange_strong(object,expected,desired) \
340 atomic_type_dispatch_16_64(InterlockedCompareExchange, object, expected, desired) == expected
341 # define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
342 atomic_compare_exchange_strong(object, expected, desired)
343 # define atomic_compare_exchange_weak(object,expected,desired) \
344 atomic_compare_exchange_strong(object, expected, desired)
345 # define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
346 atomic_compare_exchange_weak(object, expected, desired)
348 # define atomic_fetch_add(object,operand) \
349 atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, operand)
350 # define atomic_fetch_add_explicit(object,operand,order) \
351 atomic_fetch_add(object, operand)
353 # define atomic_fetch_sub(object,operand) \
354 atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, -operand)
355 # define atomic_fetch_sub_explicit(object,operand,order) \
356 atomic_fetch_sub(object, operand)
358 # define atomic_fetch_or(object,operand) \
359 atomic_type_dispatch_8_64(InterlockedOr, object, operand)
360 # define atomic_fetch_or_explicit(object,operand,order) \
361 atomic_fetch_or(object, operand)
363 # define atomic_fetch_xor(object,operand) \
364 atomic_type_dispatch_8_64(InterlockedXor, object, operand)
365 # define atomic_fetch_xor_explicit(object,operand,order) \
366 atomic_fetch_sub(object, operand)
368 # define atomic_fetch_and(object,operand) \
369 atomic_type_dispatch_8_64(InterlockedAnd, object, operand)
370 # define atomic_fetch_and_explicit(object,operand,order) \
371 atomic_fetch_and(object, operand)
373 # define atomic_flag_test_and_set(object) \
374 atomic_exchange(object, true)
376 # define atomic_flag_test_and_set_explicit(object,order) \
377 atomic_flag_test_and_set(object)
379 # define atomic_flag_clear(object) \
380 atomic_store(object, false)
382 # define atomic_flag_clear_explicit(object,order) \
383 atomic_flag_clear(object)
386 # error FIXME: implement atomic operations for this compiler.
391 * Memory storage space for an atom. Never access it directly.
398 /** Static initializer for \ref vlc_atomic_t */
399 # define VLC_ATOMIC_INIT(val) { (val) }
401 /* All functions return the atom value _after_ the operation. */
402 static inline uintptr_t vlc_atomic_get(vlc_atomic_t *atom)
404 return atomic_load(&atom->u);
407 static inline uintptr_t vlc_atomic_set(vlc_atomic_t *atom, uintptr_t v)
409 atomic_store(&atom->u, v);
413 static inline uintptr_t vlc_atomic_add(vlc_atomic_t *atom, uintptr_t v)
415 return atomic_fetch_add(&atom->u, v) + v;
418 static inline uintptr_t vlc_atomic_sub (vlc_atomic_t *atom, uintptr_t v)
420 return atomic_fetch_sub (&atom->u, v) - v;
423 static inline uintptr_t vlc_atomic_inc (vlc_atomic_t *atom)
425 return vlc_atomic_add (atom, 1);
428 static inline uintptr_t vlc_atomic_dec (vlc_atomic_t *atom)
430 return vlc_atomic_sub (atom, 1);
433 static inline uintptr_t vlc_atomic_swap(vlc_atomic_t *atom, uintptr_t v)
435 return atomic_exchange(&atom->u, v);
438 static inline uintptr_t vlc_atomic_compare_swap(vlc_atomic_t *atom,
439 uintptr_t u, uintptr_t v)
441 atomic_compare_exchange_strong(&atom->u, &u, v);
445 typedef atomic_uint_least32_t vlc_atomic_float;
447 /** Helper to retrieve a single precision from an atom. */
448 static inline float vlc_atomic_loadf(vlc_atomic_float *atom)
450 union { float f; uint32_t i; } u;
451 u.i = atomic_load(atom);
455 /** Helper to store a single precision into an atom. */
456 static inline void vlc_atomic_storef(vlc_atomic_float *atom, float f)
458 union { float f; uint32_t i; } u;
460 atomic_store(atom, u.i);