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_feature(cxx_atomic)
37 #define __CLANG_ATOMICS
38 #elif __GNUC_PREREQ__(4, 7)
39 #define __GNUC_ATOMICS
40 #elif !defined(__GNUC__)
41 #error "stdatomic.h does not support your compiler"
44 #if !defined(__CLANG_ATOMICS)
45 #define _Atomic(T) struct { volatile T __val; }
49 * 7.17.2 Initialization.
52 #if defined(__CLANG_ATOMICS)
53 #define ATOMIC_VAR_INIT(value) (value)
54 #define atomic_init(obj, value) __atomic_init(obj, value)
56 #define ATOMIC_VAR_INIT(value) { .__val = (value) }
57 #define atomic_init(obj, value) do { \
58 (obj)->__val = (value); \
63 * Clang and recent GCC both provide predefined macros for the memory
64 * orderings. If we are using a compiler that doesn't define them, use the
65 * clang values - these will be ignored in the fallback path.
68 #ifndef __ATOMIC_RELAXED
69 #define __ATOMIC_RELAXED 0
71 #ifndef __ATOMIC_CONSUME
72 #define __ATOMIC_CONSUME 1
74 #ifndef __ATOMIC_ACQUIRE
75 #define __ATOMIC_ACQUIRE 2
77 #ifndef __ATOMIC_RELEASE
78 #define __ATOMIC_RELEASE 3
80 #ifndef __ATOMIC_ACQ_REL
81 #define __ATOMIC_ACQ_REL 4
83 #ifndef __ATOMIC_SEQ_CST
84 #define __ATOMIC_SEQ_CST 5
88 * 7.17.3 Order and consistency.
90 * The memory_order_* constants that denote the barrier behaviour of the
95 memory_order_relaxed = __ATOMIC_RELAXED,
96 memory_order_consume = __ATOMIC_CONSUME,
97 memory_order_acquire = __ATOMIC_ACQUIRE,
98 memory_order_release = __ATOMIC_RELEASE,
99 memory_order_acq_rel = __ATOMIC_ACQ_REL,
100 memory_order_seq_cst = __ATOMIC_SEQ_CST
107 #if defined(__CLANG_ATOMICS) || defined(__GNUC_ATOMICS)
108 #define atomic_thread_fence(order) __atomic_thread_fence(order)
109 #define atomic_signal_fence(order) __atomic_signal_fence(order)
111 #define atomic_thread_fence(order) __sync_synchronize()
112 #define atomic_signal_fence(order) __asm volatile ("" : : : "memory")
116 * 7.17.5 Lock-free property.
119 #if defined(__CLANG_ATOMICS)
120 #define atomic_is_lock_free(obj) \
121 __atomic_is_lock_free(sizeof(obj))
122 #elif defined(__GNUC_ATOMICS)
123 #define atomic_is_lock_free(obj) \
124 __atomic_is_lock_free(sizeof((obj)->__val))
126 #define atomic_is_lock_free(obj) \
127 (sizeof((obj)->__val) <= sizeof(void *))
131 * 7.17.6 Atomic integer types.
134 typedef _Atomic(_Bool) atomic_bool;
135 typedef _Atomic(char) atomic_char;
136 typedef _Atomic(signed char) atomic_schar;
137 typedef _Atomic(unsigned char) atomic_uchar;
138 typedef _Atomic(short) atomic_short;
139 typedef _Atomic(unsigned short) atomic_ushort;
140 typedef _Atomic(int) atomic_int;
141 typedef _Atomic(unsigned int) atomic_uint;
142 typedef _Atomic(long) atomic_long;
143 typedef _Atomic(unsigned long) atomic_ulong;
144 typedef _Atomic(long long) atomic_llong;
145 typedef _Atomic(unsigned long long) atomic_ullong;
147 typedef _Atomic(__char16_t) atomic_char16_t;
148 typedef _Atomic(__char32_t) atomic_char32_t;
150 typedef _Atomic(__wchar_t) atomic_wchar_t;
151 typedef _Atomic(__int_least8_t) atomic_int_least8_t;
152 typedef _Atomic(__uint_least8_t) atomic_uint_least8_t;
153 typedef _Atomic(__int_least16_t) atomic_int_least16_t;
154 typedef _Atomic(__uint_least16_t) atomic_uint_least16_t;
155 typedef _Atomic(__int_least32_t) atomic_int_least32_t;
156 typedef _Atomic(__uint_least32_t) atomic_uint_least32_t;
157 typedef _Atomic(__int_least64_t) atomic_int_least64_t;
158 typedef _Atomic(__uint_least64_t) atomic_uint_least64_t;
159 typedef _Atomic(__int_fast8_t) atomic_int_fast8_t;
160 typedef _Atomic(__uint_fast8_t) atomic_uint_fast8_t;
161 typedef _Atomic(__int_fast16_t) atomic_int_fast16_t;
162 typedef _Atomic(__uint_fast16_t) atomic_uint_fast16_t;
163 typedef _Atomic(__int_fast32_t) atomic_int_fast32_t;
164 typedef _Atomic(__uint_fast32_t) atomic_uint_fast32_t;
165 typedef _Atomic(__int_fast64_t) atomic_int_fast64_t;
166 typedef _Atomic(__uint_fast64_t) atomic_uint_fast64_t;
167 typedef _Atomic(__intptr_t) atomic_intptr_t;
168 typedef _Atomic(__uintptr_t) atomic_uintptr_t;
169 typedef _Atomic(__size_t) atomic_size_t;
170 typedef _Atomic(__ptrdiff_t) atomic_ptrdiff_t;
171 typedef _Atomic(__intmax_t) atomic_intmax_t;
172 typedef _Atomic(__uintmax_t) atomic_uintmax_t;
175 * 7.17.7 Operations on atomic types.
179 * Compiler-specific operations.
182 #if defined(__CLANG_ATOMICS)
183 #define atomic_compare_exchange_strong_explicit(object, expected, \
184 desired, success, failure) \
185 __atomic_compare_exchange_strong(object, expected, desired, \
187 #define atomic_compare_exchange_weak_explicit(object, expected, \
188 desired, success, failure) \
189 __atomic_compare_exchange_weak(object, expected, desired, \
191 #define atomic_exchange_explicit(object, desired, order) \
192 __atomic_exchange(object, desired, order)
193 #define atomic_fetch_add_explicit(object, operand, order) \
194 __atomic_fetch_add(object, operand, order)
195 #define atomic_fetch_and_explicit(object, operand, order) \
196 __atomic_fetch_and(object, operand, order)
197 #define atomic_fetch_or_explicit(object, operand, order) \
198 __atomic_fetch_or(object, operand, order)
199 #define atomic_fetch_sub_explicit(object, operand, order) \
200 __atomic_fetch_sub(object, operand, order)
201 #define atomic_fetch_xor_explicit(object, operand, order) \
202 __atomic_fetch_xor(object, operand, order)
203 #define atomic_load_explicit(object, order) \
204 __atomic_load(object, order)
205 #define atomic_store_explicit(object, desired, order) \
206 __atomic_store(object, desired, order)
207 #elif defined(__GNUC_ATOMICS)
208 #define atomic_compare_exchange_strong_explicit(object, expected, \
209 desired, success, failure) \
210 __atomic_compare_exchange_n(&(object)->__val, expected, \
211 desired, 0, success, failure)
212 #define atomic_compare_exchange_weak_explicit(object, expected, \
213 desired, success, failure) \
214 __atomic_compare_exchange_n(&(object)->__val, expected, \
215 desired, 1, success, failure)
216 #define atomic_exchange_explicit(object, desired, order) \
217 __atomic_exchange_n(&(object)->__val, desired, order)
218 #define atomic_fetch_add_explicit(object, operand, order) \
219 __atomic_fetch_add(&(object)->__val, operand, order)
220 #define atomic_fetch_and_explicit(object, operand, order) \
221 __atomic_fetch_and(&(object)->__val, operand, order)
222 #define atomic_fetch_or_explicit(object, operand, order) \
223 __atomic_fetch_or(&(object)->__val, operand, order)
224 #define atomic_fetch_sub_explicit(object, operand, order) \
225 __atomic_fetch_sub(&(object)->__val, operand, order)
226 #define atomic_fetch_xor_explicit(object, operand, order) \
227 __atomic_fetch_xor(&(object)->__val, operand, order)
228 #define atomic_load_explicit(object, order) \
229 __atomic_load_n(&(object)->__val, order)
230 #define atomic_store_explicit(object, desired, order) \
231 __atomic_store_n(&(object)->__val, desired, order)
233 #define atomic_compare_exchange_strong_explicit(object, expected, \
234 desired, success, failure) ({ \
235 __typeof__((object)->__val) __v; \
237 __v = __sync_val_compare_and_swap(&(object)->__val, \
238 *(expected), desired); \
239 __r = *(expected) == __v; \
244 #define atomic_compare_exchange_weak_explicit(object, expected, \
245 desired, success, failure) \
246 atomic_compare_exchange_strong_explicit(object, expected, \
247 desired, success, failure)
248 #if __has_builtin(__sync_swap)
249 /* Clang provides a full-barrier atomic exchange - use it if available. */
250 #define atomic_exchange_explicit(object, desired, order) \
251 __sync_swap(&(object)->__val, desired)
254 * __sync_lock_test_and_set() is only an acquire barrier in theory (although in
255 * practice it is usually a full barrier) so we need an explicit barrier after
258 #define atomic_exchange_explicit(object, desired, order) ({ \
259 __typeof__((object)->__val) __v; \
260 __v = __sync_lock_test_and_set(&(object)->__val, desired); \
261 __sync_synchronize(); \
265 #define atomic_fetch_add_explicit(object, operand, order) \
266 __sync_fetch_and_add(&(object)->__val, operand)
267 #define atomic_fetch_and_explicit(object, operand, order) \
268 __sync_fetch_and_and(&(object)->__val, operand)
269 #define atomic_fetch_or_explicit(object, operand, order) \
270 __sync_fetch_and_or(&(object)->__val, operand)
271 #define atomic_fetch_sub_explicit(object, operand, order) \
272 __sync_fetch_and_sub(&(object)->__val, operand)
273 #define atomic_fetch_xor_explicit(object, operand, order) \
274 __sync_fetch_and_xor(&(object)->__val, operand)
275 #define atomic_load_explicit(object, order) \
276 __sync_fetch_and_add(&(object)->__val, 0)
277 #define atomic_store_explicit(object, desired, order) do { \
278 __sync_synchronize(); \
279 (object)->__val = (desired); \
280 __sync_synchronize(); \
285 * Convenience functions.
288 #define atomic_compare_exchange_strong(object, expected, desired) \
289 atomic_compare_exchange_strong_explicit(object, expected, \
290 desired, memory_order_seq_cst, memory_order_seq_cst)
291 #define atomic_compare_exchange_weak(object, expected, desired) \
292 atomic_compare_exchange_weak_explicit(object, expected, \
293 desired, memory_order_seq_cst, memory_order_seq_cst)
294 #define atomic_exchange(object, desired) \
295 atomic_exchange_explicit(object, desired, memory_order_seq_cst)
296 #define atomic_fetch_add(object, operand) \
297 atomic_fetch_add_explicit(object, operand, memory_order_seq_cst)
298 #define atomic_fetch_and(object, operand) \
299 atomic_fetch_and_explicit(object, operand, memory_order_seq_cst)
300 #define atomic_fetch_or(object, operand) \
301 atomic_fetch_or_explicit(object, operand, memory_order_seq_cst)
302 #define atomic_fetch_sub(object, operand) \
303 atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst)
304 #define atomic_fetch_xor(object, operand) \
305 atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst)
306 #define atomic_load(object) \
307 atomic_load_explicit(object, memory_order_seq_cst)
308 #define atomic_store(object, desired) \
309 atomic_store_explicit(object, desired, memory_order_seq_cst)
312 * 7.17.8 Atomic flag type and operations.
315 typedef atomic_bool atomic_flag;
317 #define ATOMIC_FLAG_INIT ATOMIC_VAR_INIT(0)
319 #define atomic_flag_clear_explicit(object, order) \
320 atomic_store_explicit(object, 0, order)
321 #define atomic_flag_test_and_set_explicit(object, order) \
322 atomic_compare_exchange_strong_explicit(object, 0, 1, order, order)
324 #define atomic_flag_clear(object) \
325 atomic_flag_clear_explicit(object, memory_order_seq_cst)
326 #define atomic_flag_test_and_set(object) \
327 atomic_flag_test_and_set_explicit(object, memory_order_seq_cst)
329 #endif /* !_STDATOMIC_H_ */