2 * Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
3 * David Chisnall <theraven@FreeBSD.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 #include <sys/cdefs.h>
34 #include <sys/_types.h>
36 #if __has_extension(c_atomic) || __has_extension(cxx_atomic)
37 #define __CLANG_ATOMICS
38 #elif __GNUC_PREREQ__(4, 7)
39 #define __GNUC_ATOMICS
40 #elif defined(__GNUC__)
41 #define __SYNC_ATOMICS
43 #error "stdatomic.h does not support your compiler"
47 * 7.17.1 Atomic lock-free macros.
50 #ifdef __GCC_ATOMIC_BOOL_LOCK_FREE
51 #define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE
53 #ifdef __GCC_ATOMIC_CHAR_LOCK_FREE
54 #define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE
56 #ifdef __GCC_ATOMIC_CHAR16_T_LOCK_FREE
57 #define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE
59 #ifdef __GCC_ATOMIC_CHAR32_T_LOCK_FREE
60 #define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE
62 #ifdef __GCC_ATOMIC_WCHAR_T_LOCK_FREE
63 #define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE
65 #ifdef __GCC_ATOMIC_SHORT_LOCK_FREE
66 #define ATOMIC_SHORT_LOCK_FREE __GCC_ATOMIC_SHORT_LOCK_FREE
68 #ifdef __GCC_ATOMIC_INT_LOCK_FREE
69 #define ATOMIC_INT_LOCK_FREE __GCC_ATOMIC_INT_LOCK_FREE
71 #ifdef __GCC_ATOMIC_LONG_LOCK_FREE
72 #define ATOMIC_LONG_LOCK_FREE __GCC_ATOMIC_LONG_LOCK_FREE
74 #ifdef __GCC_ATOMIC_LLONG_LOCK_FREE
75 #define ATOMIC_LLONG_LOCK_FREE __GCC_ATOMIC_LLONG_LOCK_FREE
77 #ifdef __GCC_ATOMIC_POINTER_LOCK_FREE
78 #define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE
82 * 7.17.2 Initialization.
85 #if defined(__CLANG_ATOMICS)
86 #define ATOMIC_VAR_INIT(value) (value)
87 #define atomic_init(obj, value) __c11_atomic_init(obj, value)
89 #define ATOMIC_VAR_INIT(value) { .__val = (value) }
90 #define atomic_init(obj, value) ((void)((obj)->__val = (value)))
94 * Clang and recent GCC both provide predefined macros for the memory
95 * orderings. If we are using a compiler that doesn't define them, use the
96 * clang values - these will be ignored in the fallback path.
99 #ifndef __ATOMIC_RELAXED
100 #define __ATOMIC_RELAXED 0
102 #ifndef __ATOMIC_CONSUME
103 #define __ATOMIC_CONSUME 1
105 #ifndef __ATOMIC_ACQUIRE
106 #define __ATOMIC_ACQUIRE 2
108 #ifndef __ATOMIC_RELEASE
109 #define __ATOMIC_RELEASE 3
111 #ifndef __ATOMIC_ACQ_REL
112 #define __ATOMIC_ACQ_REL 4
114 #ifndef __ATOMIC_SEQ_CST
115 #define __ATOMIC_SEQ_CST 5
119 * 7.17.3 Order and consistency.
121 * The memory_order_* constants that denote the barrier behaviour of the
126 memory_order_relaxed = __ATOMIC_RELAXED,
127 memory_order_consume = __ATOMIC_CONSUME,
128 memory_order_acquire = __ATOMIC_ACQUIRE,
129 memory_order_release = __ATOMIC_RELEASE,
130 memory_order_acq_rel = __ATOMIC_ACQ_REL,
131 memory_order_seq_cst = __ATOMIC_SEQ_CST
138 #ifdef __CLANG_ATOMICS
139 #define atomic_thread_fence(order) __c11_atomic_thread_fence(order)
140 #define atomic_signal_fence(order) __c11_atomic_signal_fence(order)
141 #elif defined(__GNUC_ATOMICS)
142 #define atomic_thread_fence(order) __atomic_thread_fence(order)
143 #define atomic_signal_fence(order) __atomic_signal_fence(order)
145 #define atomic_thread_fence(order) ((void)(order), __sync_synchronize())
146 #define atomic_signal_fence(order) __extension__ ({ \
148 __asm volatile ("" ::: "memory"); \
154 * 7.17.5 Lock-free property.
158 /* Atomics in kernelspace are always lock-free. */
159 #define atomic_is_lock_free(obj) \
160 ((void)(obj), (_Bool)1)
161 #elif defined(__CLANG_ATOMICS)
162 #define atomic_is_lock_free(obj) \
163 __atomic_is_lock_free(sizeof(*(obj)), obj)
164 #elif defined(__GNUC_ATOMICS)
165 #define atomic_is_lock_free(obj) \
166 __atomic_is_lock_free(sizeof((obj)->__val), &(obj)->__val)
168 #define atomic_is_lock_free(obj) \
169 ((void)(obj), sizeof((obj)->__val) <= sizeof(void *))
173 * 7.17.6 Atomic integer types.
176 typedef _Atomic(_Bool) atomic_bool;
177 typedef _Atomic(char) atomic_char;
178 typedef _Atomic(signed char) atomic_schar;
179 typedef _Atomic(unsigned char) atomic_uchar;
180 typedef _Atomic(short) atomic_short;
181 typedef _Atomic(unsigned short) atomic_ushort;
182 typedef _Atomic(int) atomic_int;
183 typedef _Atomic(unsigned int) atomic_uint;
184 typedef _Atomic(long) atomic_long;
185 typedef _Atomic(unsigned long) atomic_ulong;
186 typedef _Atomic(long long) atomic_llong;
187 typedef _Atomic(unsigned long long) atomic_ullong;
188 typedef _Atomic(__char16_t) atomic_char16_t;
189 typedef _Atomic(__char32_t) atomic_char32_t;
190 typedef _Atomic(__wchar_t) atomic_wchar_t;
191 typedef _Atomic(__int_least8_t) atomic_int_least8_t;
192 typedef _Atomic(__uint_least8_t) atomic_uint_least8_t;
193 typedef _Atomic(__int_least16_t) atomic_int_least16_t;
194 typedef _Atomic(__uint_least16_t) atomic_uint_least16_t;
195 typedef _Atomic(__int_least32_t) atomic_int_least32_t;
196 typedef _Atomic(__uint_least32_t) atomic_uint_least32_t;
197 typedef _Atomic(__int_least64_t) atomic_int_least64_t;
198 typedef _Atomic(__uint_least64_t) atomic_uint_least64_t;
199 typedef _Atomic(__int_fast8_t) atomic_int_fast8_t;
200 typedef _Atomic(__uint_fast8_t) atomic_uint_fast8_t;
201 typedef _Atomic(__int_fast16_t) atomic_int_fast16_t;
202 typedef _Atomic(__uint_fast16_t) atomic_uint_fast16_t;
203 typedef _Atomic(__int_fast32_t) atomic_int_fast32_t;
204 typedef _Atomic(__uint_fast32_t) atomic_uint_fast32_t;
205 typedef _Atomic(__int_fast64_t) atomic_int_fast64_t;
206 typedef _Atomic(__uint_fast64_t) atomic_uint_fast64_t;
207 typedef _Atomic(__intptr_t) atomic_intptr_t;
208 typedef _Atomic(__uintptr_t) atomic_uintptr_t;
209 typedef _Atomic(__size_t) atomic_size_t;
210 typedef _Atomic(__ptrdiff_t) atomic_ptrdiff_t;
211 typedef _Atomic(__intmax_t) atomic_intmax_t;
212 typedef _Atomic(__uintmax_t) atomic_uintmax_t;
215 * 7.17.7 Operations on atomic types.
219 * Compiler-specific operations.
222 #if defined(__CLANG_ATOMICS)
223 #define atomic_compare_exchange_strong_explicit(object, expected, \
224 desired, success, failure) \
225 __c11_atomic_compare_exchange_strong(object, expected, desired, \
227 #define atomic_compare_exchange_weak_explicit(object, expected, \
228 desired, success, failure) \
229 __c11_atomic_compare_exchange_weak(object, expected, desired, \
231 #define atomic_exchange_explicit(object, desired, order) \
232 __c11_atomic_exchange(object, desired, order)
233 #define atomic_fetch_add_explicit(object, operand, order) \
234 __c11_atomic_fetch_add(object, operand, order)
235 #define atomic_fetch_and_explicit(object, operand, order) \
236 __c11_atomic_fetch_and(object, operand, order)
237 #define atomic_fetch_or_explicit(object, operand, order) \
238 __c11_atomic_fetch_or(object, operand, order)
239 #define atomic_fetch_sub_explicit(object, operand, order) \
240 __c11_atomic_fetch_sub(object, operand, order)
241 #define atomic_fetch_xor_explicit(object, operand, order) \
242 __c11_atomic_fetch_xor(object, operand, order)
243 #define atomic_load_explicit(object, order) \
244 __c11_atomic_load(object, order)
245 #define atomic_store_explicit(object, desired, order) \
246 __c11_atomic_store(object, desired, order)
247 #elif defined(__GNUC_ATOMICS)
248 #define atomic_compare_exchange_strong_explicit(object, expected, \
249 desired, success, failure) \
250 __atomic_compare_exchange_n(&(object)->__val, expected, \
251 desired, 0, success, failure)
252 #define atomic_compare_exchange_weak_explicit(object, expected, \
253 desired, success, failure) \
254 __atomic_compare_exchange_n(&(object)->__val, expected, \
255 desired, 1, success, failure)
256 #define atomic_exchange_explicit(object, desired, order) \
257 __atomic_exchange_n(&(object)->__val, desired, order)
258 #define atomic_fetch_add_explicit(object, operand, order) \
259 __atomic_fetch_add(&(object)->__val, operand, order)
260 #define atomic_fetch_and_explicit(object, operand, order) \
261 __atomic_fetch_and(&(object)->__val, operand, order)
262 #define atomic_fetch_or_explicit(object, operand, order) \
263 __atomic_fetch_or(&(object)->__val, operand, order)
264 #define atomic_fetch_sub_explicit(object, operand, order) \
265 __atomic_fetch_sub(&(object)->__val, operand, order)
266 #define atomic_fetch_xor_explicit(object, operand, order) \
267 __atomic_fetch_xor(&(object)->__val, operand, order)
268 #define atomic_load_explicit(object, order) \
269 __atomic_load_n(&(object)->__val, order)
270 #define atomic_store_explicit(object, desired, order) \
271 __atomic_store_n(&(object)->__val, desired, order)
273 #define atomic_compare_exchange_strong_explicit(object, expected, \
274 desired, success, failure) __extension__ ({ \
275 __typeof__(expected) __ep = (expected); \
276 __typeof__(*__ep) __e = *__ep; \
277 (void)(success); (void)(failure); \
278 (*__ep = __sync_val_compare_and_swap(&(object)->__val, \
279 __e, desired)) == __e; \
281 #define atomic_compare_exchange_weak_explicit(object, expected, \
282 desired, success, failure) \
283 atomic_compare_exchange_strong_explicit(object, expected, \
284 desired, success, failure)
285 #if __has_builtin(__sync_swap)
286 /* Clang provides a full-barrier atomic exchange - use it if available. */
287 #define atomic_exchange_explicit(object, desired, order) \
288 ((void)(order), __sync_swap(&(object)->__val, desired))
291 * __sync_lock_test_and_set() is only an acquire barrier in theory (although in
292 * practice it is usually a full barrier) so we need an explicit barrier before
295 #define atomic_exchange_explicit(object, desired, order) \
297 __typeof__(object) __o = (object); \
298 __typeof__(desired) __d = (desired); \
300 __sync_synchronize(); \
301 __sync_lock_test_and_set(&(__o)->__val, __d); \
304 #define atomic_fetch_add_explicit(object, operand, order) \
305 ((void)(order), __sync_fetch_and_add(&(object)->__val, operand))
306 #define atomic_fetch_and_explicit(object, operand, order) \
307 ((void)(order), __sync_fetch_and_and(&(object)->__val, operand))
308 #define atomic_fetch_or_explicit(object, operand, order) \
309 ((void)(order), __sync_fetch_and_or(&(object)->__val, operand))
310 #define atomic_fetch_sub_explicit(object, operand, order) \
311 ((void)(order), __sync_fetch_and_sub(&(object)->__val, operand))
312 #define atomic_fetch_xor_explicit(object, operand, order) \
313 ((void)(order), __sync_fetch_and_xor(&(object)->__val, operand))
314 #define atomic_load_explicit(object, order) \
315 ((void)(order), __sync_fetch_and_add(&(object)->__val, 0))
316 #define atomic_store_explicit(object, desired, order) \
317 ((void)atomic_exchange_explicit(object, desired, order))
321 * Convenience functions.
324 #define atomic_compare_exchange_strong(object, expected, desired) \
325 atomic_compare_exchange_strong_explicit(object, expected, \
326 desired, memory_order_seq_cst, memory_order_seq_cst)
327 #define atomic_compare_exchange_weak(object, expected, desired) \
328 atomic_compare_exchange_weak_explicit(object, expected, \
329 desired, memory_order_seq_cst, memory_order_seq_cst)
330 #define atomic_exchange(object, desired) \
331 atomic_exchange_explicit(object, desired, memory_order_seq_cst)
332 #define atomic_fetch_add(object, operand) \
333 atomic_fetch_add_explicit(object, operand, memory_order_seq_cst)
334 #define atomic_fetch_and(object, operand) \
335 atomic_fetch_and_explicit(object, operand, memory_order_seq_cst)
336 #define atomic_fetch_or(object, operand) \
337 atomic_fetch_or_explicit(object, operand, memory_order_seq_cst)
338 #define atomic_fetch_sub(object, operand) \
339 atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst)
340 #define atomic_fetch_xor(object, operand) \
341 atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst)
342 #define atomic_load(object) \
343 atomic_load_explicit(object, memory_order_seq_cst)
344 #define atomic_store(object, desired) \
345 atomic_store_explicit(object, desired, memory_order_seq_cst)
348 * 7.17.8 Atomic flag type and operations.
351 typedef atomic_bool atomic_flag;
353 #define ATOMIC_FLAG_INIT ATOMIC_VAR_INIT(0)
355 #define atomic_flag_clear_explicit(object, order) \
356 atomic_store_explicit(object, 0, order)
357 #define atomic_flag_test_and_set_explicit(object, order) \
358 atomic_compare_exchange_strong_explicit(object, 0, 1, order, order)
360 #define atomic_flag_clear(object) \
361 atomic_flag_clear_explicit(object, memory_order_seq_cst)
362 #define atomic_flag_test_and_set(object) \
363 atomic_flag_test_and_set_explicit(object, memory_order_seq_cst)
365 #endif /* !_STDATOMIC_H_ */