stdatomic.h revision 254783
1/*- 2 * Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org> 3 * David Chisnall <theraven@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 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. 14 * 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 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: stable/9/include/stdatomic.h 254783 2013-08-24 13:49:43Z emaste $ 28 */ 29 30#ifndef _STDATOMIC_H_ 31#define _STDATOMIC_H_ 32 33#include <sys/cdefs.h> 34#include <sys/_types.h> 35 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#error "stdatomic.h does not support your compiler" 42#endif 43 44#if !defined(__CLANG_ATOMICS) 45#define _Atomic(T) struct { volatile T __val; } 46#endif 47 48/* 49 * 7.17.2 Initialization. 50 */ 51 52#if defined(__CLANG_ATOMICS) 53#define ATOMIC_VAR_INIT(value) (value) 54#define atomic_init(obj, value) __c11_atomic_init(obj, value) 55#else 56#define ATOMIC_VAR_INIT(value) { .__val = (value) } 57#define atomic_init(obj, value) ((void)((obj)->__val = (value))) 58#endif 59 60/* 61 * Clang and recent GCC both provide predefined macros for the memory 62 * orderings. If we are using a compiler that doesn't define them, use the 63 * clang values - these will be ignored in the fallback path. 64 */ 65 66#ifndef __ATOMIC_RELAXED 67#define __ATOMIC_RELAXED 0 68#endif 69#ifndef __ATOMIC_CONSUME 70#define __ATOMIC_CONSUME 1 71#endif 72#ifndef __ATOMIC_ACQUIRE 73#define __ATOMIC_ACQUIRE 2 74#endif 75#ifndef __ATOMIC_RELEASE 76#define __ATOMIC_RELEASE 3 77#endif 78#ifndef __ATOMIC_ACQ_REL 79#define __ATOMIC_ACQ_REL 4 80#endif 81#ifndef __ATOMIC_SEQ_CST 82#define __ATOMIC_SEQ_CST 5 83#endif 84 85/* 86 * 7.17.3 Order and consistency. 87 * 88 * The memory_order_* constants that denote the barrier behaviour of the 89 * atomic operations. 90 */ 91 92enum memory_order { 93 memory_order_relaxed = __ATOMIC_RELAXED, 94 memory_order_consume = __ATOMIC_CONSUME, 95 memory_order_acquire = __ATOMIC_ACQUIRE, 96 memory_order_release = __ATOMIC_RELEASE, 97 memory_order_acq_rel = __ATOMIC_ACQ_REL, 98 memory_order_seq_cst = __ATOMIC_SEQ_CST 99}; 100 101/* 102 * 7.17.4 Fences. 103 */ 104 105#ifdef __CLANG_ATOMICS 106#define atomic_thread_fence(order) __c11_atomic_thread_fence(order) 107#define atomic_signal_fence(order) __c11_atomic_signal_fence(order) 108#elif defined(__GNUC_ATOMICS) 109#define atomic_thread_fence(order) __atomic_thread_fence(order) 110#define atomic_signal_fence(order) __atomic_signal_fence(order) 111#else 112#define atomic_thread_fence(order) ((void)(order), __sync_synchronize()) 113#define atomic_signal_fence(order) __extension__ ({ \ 114 (void)(order); \ 115 __asm volatile ("" ::: "memory"); \ 116 (void)0; \ 117}) 118#endif 119 120/* 121 * 7.17.5 Lock-free property. 122 */ 123 124#if defined(__CLANG_ATOMICS) || defined(__GNUC_ATOMICS) 125#define atomic_is_lock_free(obj) \ 126 __atomic_is_lock_free(sizeof((obj)->__val), &(obj)->__val) 127#else 128#define atomic_is_lock_free(obj) \ 129 ((void)(obj), sizeof((obj)->__val) <= sizeof(void *)) 130#endif 131 132/* 133 * 7.17.6 Atomic integer types. 134 */ 135 136typedef _Atomic(_Bool) atomic_bool; 137typedef _Atomic(char) atomic_char; 138typedef _Atomic(signed char) atomic_schar; 139typedef _Atomic(unsigned char) atomic_uchar; 140typedef _Atomic(short) atomic_short; 141typedef _Atomic(unsigned short) atomic_ushort; 142typedef _Atomic(int) atomic_int; 143typedef _Atomic(unsigned int) atomic_uint; 144typedef _Atomic(long) atomic_long; 145typedef _Atomic(unsigned long) atomic_ulong; 146typedef _Atomic(long long) atomic_llong; 147typedef _Atomic(unsigned long long) atomic_ullong; 148#if 0 149typedef _Atomic(__char16_t) atomic_char16_t; 150typedef _Atomic(__char32_t) atomic_char32_t; 151#endif 152typedef _Atomic(__wchar_t) atomic_wchar_t; 153typedef _Atomic(__int_least8_t) atomic_int_least8_t; 154typedef _Atomic(__uint_least8_t) atomic_uint_least8_t; 155typedef _Atomic(__int_least16_t) atomic_int_least16_t; 156typedef _Atomic(__uint_least16_t) atomic_uint_least16_t; 157typedef _Atomic(__int_least32_t) atomic_int_least32_t; 158typedef _Atomic(__uint_least32_t) atomic_uint_least32_t; 159typedef _Atomic(__int_least64_t) atomic_int_least64_t; 160typedef _Atomic(__uint_least64_t) atomic_uint_least64_t; 161typedef _Atomic(__int_fast8_t) atomic_int_fast8_t; 162typedef _Atomic(__uint_fast8_t) atomic_uint_fast8_t; 163typedef _Atomic(__int_fast16_t) atomic_int_fast16_t; 164typedef _Atomic(__uint_fast16_t) atomic_uint_fast16_t; 165typedef _Atomic(__int_fast32_t) atomic_int_fast32_t; 166typedef _Atomic(__uint_fast32_t) atomic_uint_fast32_t; 167typedef _Atomic(__int_fast64_t) atomic_int_fast64_t; 168typedef _Atomic(__uint_fast64_t) atomic_uint_fast64_t; 169typedef _Atomic(__intptr_t) atomic_intptr_t; 170typedef _Atomic(__uintptr_t) atomic_uintptr_t; 171typedef _Atomic(__size_t) atomic_size_t; 172typedef _Atomic(__ptrdiff_t) atomic_ptrdiff_t; 173typedef _Atomic(__intmax_t) atomic_intmax_t; 174typedef _Atomic(__uintmax_t) atomic_uintmax_t; 175 176/* 177 * 7.17.7 Operations on atomic types. 178 */ 179 180/* 181 * Compiler-specific operations. 182 */ 183 184#if defined(__CLANG_ATOMICS) 185#define atomic_compare_exchange_strong_explicit(object, expected, \ 186 desired, success, failure) \ 187 __c11_atomic_compare_exchange_strong(object, expected, desired, \ 188 success, failure) 189#define atomic_compare_exchange_weak_explicit(object, expected, \ 190 desired, success, failure) \ 191 __c11_atomic_compare_exchange_weak(object, expected, desired, \ 192 success, failure) 193#define atomic_exchange_explicit(object, desired, order) \ 194 __c11_atomic_exchange(object, desired, order) 195#define atomic_fetch_add_explicit(object, operand, order) \ 196 __c11_atomic_fetch_add(object, operand, order) 197#define atomic_fetch_and_explicit(object, operand, order) \ 198 __c11_atomic_fetch_and(object, operand, order) 199#define atomic_fetch_or_explicit(object, operand, order) \ 200 __c11_atomic_fetch_or(object, operand, order) 201#define atomic_fetch_sub_explicit(object, operand, order) \ 202 __c11_atomic_fetch_sub(object, operand, order) 203#define atomic_fetch_xor_explicit(object, operand, order) \ 204 __c11_atomic_fetch_xor(object, operand, order) 205#define atomic_load_explicit(object, order) \ 206 __c11_atomic_load(object, order) 207#define atomic_store_explicit(object, desired, order) \ 208 __c11_atomic_store(object, desired, order) 209#elif defined(__GNUC_ATOMICS) 210#define atomic_compare_exchange_strong_explicit(object, expected, \ 211 desired, success, failure) \ 212 __atomic_compare_exchange_n(&(object)->__val, expected, \ 213 desired, 0, success, failure) 214#define atomic_compare_exchange_weak_explicit(object, expected, \ 215 desired, success, failure) \ 216 __atomic_compare_exchange_n(&(object)->__val, expected, \ 217 desired, 1, success, failure) 218#define atomic_exchange_explicit(object, desired, order) \ 219 __atomic_exchange_n(&(object)->__val, desired, order) 220#define atomic_fetch_add_explicit(object, operand, order) \ 221 __atomic_fetch_add(&(object)->__val, operand, order) 222#define atomic_fetch_and_explicit(object, operand, order) \ 223 __atomic_fetch_and(&(object)->__val, operand, order) 224#define atomic_fetch_or_explicit(object, operand, order) \ 225 __atomic_fetch_or(&(object)->__val, operand, order) 226#define atomic_fetch_sub_explicit(object, operand, order) \ 227 __atomic_fetch_sub(&(object)->__val, operand, order) 228#define atomic_fetch_xor_explicit(object, operand, order) \ 229 __atomic_fetch_xor(&(object)->__val, operand, order) 230#define atomic_load_explicit(object, order) \ 231 __atomic_load_n(&(object)->__val, order) 232#define atomic_store_explicit(object, desired, order) \ 233 __atomic_store_n(&(object)->__val, desired, order) 234#else 235#define atomic_compare_exchange_strong_explicit(object, expected, \ 236 desired, success, failure) __extension__ ({ \ 237 __typeof__(expected) __ep = (expected); \ 238 __typeof__(*__ep) __e = *__ep; \ 239 (void)(success); (void)(failure); \ 240 (_Bool)((*__ep = __sync_val_compare_and_swap(&(object)->__val, \ 241 __e, desired)) == __e); \ 242}) 243#define atomic_compare_exchange_weak_explicit(object, expected, \ 244 desired, success, failure) \ 245 atomic_compare_exchange_strong_explicit(object, expected, \ 246 desired, success, failure) 247#if __has_builtin(__sync_swap) 248/* Clang provides a full-barrier atomic exchange - use it if available. */ 249#define atomic_exchange_explicit(object, desired, order) \ 250 ((void)(order), __sync_swap(&(object)->__val, desired)) 251#else 252/* 253 * __sync_lock_test_and_set() is only an acquire barrier in theory (although in 254 * practice it is usually a full barrier) so we need an explicit barrier before 255 * it. 256 */ 257#define atomic_exchange_explicit(object, desired, order) \ 258__extension__ ({ \ 259 __typeof__(object) __o = (object); \ 260 __typeof__(desired) __d = (desired); \ 261 (void)(order); \ 262 __sync_synchronize(); \ 263 __sync_lock_test_and_set(&(__o)->__val, __d); \ 264}) 265#endif 266#define atomic_fetch_add_explicit(object, operand, order) \ 267 ((void)(order), __sync_fetch_and_add(&(object)->__val, operand)) 268#define atomic_fetch_and_explicit(object, operand, order) \ 269 ((void)(order), __sync_fetch_and_and(&(object)->__val, operand)) 270#define atomic_fetch_or_explicit(object, operand, order) \ 271 ((void)(order), __sync_fetch_and_or(&(object)->__val, operand)) 272#define atomic_fetch_sub_explicit(object, operand, order) \ 273 ((void)(order), __sync_fetch_and_sub(&(object)->__val, operand)) 274#define atomic_fetch_xor_explicit(object, operand, order) \ 275 ((void)(order), __sync_fetch_and_xor(&(object)->__val, operand)) 276#define atomic_load_explicit(object, order) \ 277 ((void)(order), __sync_fetch_and_add(&(object)->__val, 0)) 278#define atomic_store_explicit(object, desired, order) \ 279 ((void)atomic_exchange_explicit(object, desired, order)) 280#endif 281 282/* 283 * Convenience functions. 284 */ 285 286#define atomic_compare_exchange_strong(object, expected, desired) \ 287 atomic_compare_exchange_strong_explicit(object, expected, \ 288 desired, memory_order_seq_cst, memory_order_seq_cst) 289#define atomic_compare_exchange_weak(object, expected, desired) \ 290 atomic_compare_exchange_weak_explicit(object, expected, \ 291 desired, memory_order_seq_cst, memory_order_seq_cst) 292#define atomic_exchange(object, desired) \ 293 atomic_exchange_explicit(object, desired, memory_order_seq_cst) 294#define atomic_fetch_add(object, operand) \ 295 atomic_fetch_add_explicit(object, operand, memory_order_seq_cst) 296#define atomic_fetch_and(object, operand) \ 297 atomic_fetch_and_explicit(object, operand, memory_order_seq_cst) 298#define atomic_fetch_or(object, operand) \ 299 atomic_fetch_or_explicit(object, operand, memory_order_seq_cst) 300#define atomic_fetch_sub(object, operand) \ 301 atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst) 302#define atomic_fetch_xor(object, operand) \ 303 atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst) 304#define atomic_load(object) \ 305 atomic_load_explicit(object, memory_order_seq_cst) 306#define atomic_store(object, desired) \ 307 atomic_store_explicit(object, desired, memory_order_seq_cst) 308 309/* 310 * 7.17.8 Atomic flag type and operations. 311 */ 312 313typedef atomic_bool atomic_flag; 314 315#define ATOMIC_FLAG_INIT ATOMIC_VAR_INIT(0) 316 317#define atomic_flag_clear_explicit(object, order) \ 318 atomic_store_explicit(object, 0, order) 319#define atomic_flag_test_and_set_explicit(object, order) \ 320 atomic_exchange_explicit(object, 1, order) 321 322#define atomic_flag_clear(object) \ 323 atomic_flag_clear_explicit(object, memory_order_seq_cst) 324#define atomic_flag_test_and_set(object) \ 325 atomic_flag_test_and_set_explicit(object, memory_order_seq_cst) 326 327#endif /* !_STDATOMIC_H_ */ 328