include/stdatomic.h

   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  * $FreeBSD$
  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_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"
  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) do {                                    \
  58         (obj)->__val = (value);                                         \
  59 } while (0)
  60 #endif
  61
  62 /*
  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.
  66  */
  67
  68 #ifndef __ATOMIC_RELAXED
  69 #define __ATOMIC_RELAXED                0
  70 #endif
  71 #ifndef __ATOMIC_CONSUME
  72 #define __ATOMIC_CONSUME                1
  73 #endif
  74 #ifndef __ATOMIC_ACQUIRE
  75 #define __ATOMIC_ACQUIRE                2
  76 #endif
  77 #ifndef __ATOMIC_RELEASE
  78 #define __ATOMIC_RELEASE                3
  79 #endif
  80 #ifndef __ATOMIC_ACQ_REL
  81 #define __ATOMIC_ACQ_REL                4
  82 #endif
  83 #ifndef __ATOMIC_SEQ_CST
  84 #define __ATOMIC_SEQ_CST                5
  85 #endif
  86
  87 /*
  88  * 7.17.3 Order and consistency.
  89  *
  90  * The memory_order_* constants that denote the barrier behaviour of the
  91  * atomic operations.
  92  */
  93
  94 enum memory_order {
  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
 101 };
 102
 103 /*
 104  * 7.17.4 Fences.
 105  */
 106
 107 #ifdef __CLANG_ATOMICS
 108 #define atomic_thread_fence(order)      __c11_atomic_thread_fence(order)
 109 #define atomic_signal_fence(order)      __c11_atomic_signal_fence(order)
 110 #elif defined(__GNUC_ATOMICS)
 111 #define atomic_thread_fence(order)      __atomic_thread_fence(order)
 112 #define atomic_signal_fence(order)      __atomic_signal_fence(order)
 113 #else
 114 #define atomic_thread_fence(order)      __sync_synchronize()
 115 #define atomic_signal_fence(order)      __asm volatile ("" : : : "memory")
 116 #endif
 117
 118 /*
 119  * 7.17.5 Lock-free property.
 120  */
 121
 122 #if defined(__CLANG_ATOMICS)
 123 #define atomic_is_lock_free(obj) \
 124         __c11_atomic_is_lock_free(sizeof(obj))
 125 #elif defined(__GNUC_ATOMICS)
 126 #define atomic_is_lock_free(obj) \
 127         __atomic_is_lock_free(sizeof((obj)->__val))
 128 #else
 129 #define atomic_is_lock_free(obj) \
 130         (sizeof((obj)->__val) <= sizeof(void *))
 131 #endif
 132
 133 /*
 134  * 7.17.6 Atomic integer types.
 135  */
 136
 137 typedef _Atomic(_Bool)                  atomic_bool;
 138 typedef _Atomic(char)                   atomic_char;
 139 typedef _Atomic(signed char)            atomic_schar;
 140 typedef _Atomic(unsigned char)          atomic_uchar;
 141 typedef _Atomic(short)                  atomic_short;
 142 typedef _Atomic(unsigned short)         atomic_ushort;
 143 typedef _Atomic(int)                    atomic_int;
 144 typedef _Atomic(unsigned int)           atomic_uint;
 145 typedef _Atomic(long)                   atomic_long;
 146 typedef _Atomic(unsigned long)          atomic_ulong;
 147 typedef _Atomic(long long)              atomic_llong;
 148 typedef _Atomic(unsigned long long)     atomic_ullong;
 149 #if 0
 150 typedef _Atomic(__char16_t)             atomic_char16_t;
 151 typedef _Atomic(__char32_t)             atomic_char32_t;
 152 #endif
 153 typedef _Atomic(__wchar_t)              atomic_wchar_t;
 154 typedef _Atomic(__int_least8_t)         atomic_int_least8_t;
 155 typedef _Atomic(__uint_least8_t)        atomic_uint_least8_t;
 156 typedef _Atomic(__int_least16_t)        atomic_int_least16_t;
 157 typedef _Atomic(__uint_least16_t)       atomic_uint_least16_t;
 158 typedef _Atomic(__int_least32_t)        atomic_int_least32_t;
 159 typedef _Atomic(__uint_least32_t)       atomic_uint_least32_t;
 160 typedef _Atomic(__int_least64_t)        atomic_int_least64_t;
 161 typedef _Atomic(__uint_least64_t)       atomic_uint_least64_t;
 162 typedef _Atomic(__int_fast8_t)          atomic_int_fast8_t;
 163 typedef _Atomic(__uint_fast8_t)         atomic_uint_fast8_t;
 164 typedef _Atomic(__int_fast16_t)         atomic_int_fast16_t;
 165 typedef _Atomic(__uint_fast16_t)        atomic_uint_fast16_t;
 166 typedef _Atomic(__int_fast32_t)         atomic_int_fast32_t;
 167 typedef _Atomic(__uint_fast32_t)        atomic_uint_fast32_t;
 168 typedef _Atomic(__int_fast64_t)         atomic_int_fast64_t;
 169 typedef _Atomic(__uint_fast64_t)        atomic_uint_fast64_t;
 170 typedef _Atomic(__intptr_t)             atomic_intptr_t;
 171 typedef _Atomic(__uintptr_t)            atomic_uintptr_t;
 172 typedef _Atomic(__size_t)               atomic_size_t;
 173 typedef _Atomic(__ptrdiff_t)            atomic_ptrdiff_t;
 174 typedef _Atomic(__intmax_t)             atomic_intmax_t;
 175 typedef _Atomic(__uintmax_t)            atomic_uintmax_t;
 176
 177 /*
 178  * 7.17.7 Operations on atomic types.
 179  */
 180
 181 /*
 182  * Compiler-specific operations.
 183  */
 184
 185 #if defined(__CLANG_ATOMICS)
 186 #define atomic_compare_exchange_strong_explicit(object, expected,       \
 187     desired, success, failure)                                          \
 188         __c11_atomic_compare_exchange_strong(object, expected, desired, \
 189             success, failure)
 190 #define atomic_compare_exchange_weak_explicit(object, expected,         \
 191     desired, success, failure)                                          \
 192         __c11_atomic_compare_exchange_weak(object, expected, desired,   \
 193             success, failure)
 194 #define atomic_exchange_explicit(object, desired, order)                \
 195         __c11_atomic_exchange(object, desired, order)
 196 #define atomic_fetch_add_explicit(object, operand, order)               \
 197         __c11_atomic_fetch_add(object, operand, order)
 198 #define atomic_fetch_and_explicit(object, operand, order)               \
 199         __c11_atomic_fetch_and(object, operand, order)
 200 #define atomic_fetch_or_explicit(object, operand, order)                \
 201         __c11_atomic_fetch_or(object, operand, order)
 202 #define atomic_fetch_sub_explicit(object, operand, order)               \
 203         __c11_atomic_fetch_sub(object, operand, order)
 204 #define atomic_fetch_xor_explicit(object, operand, order)               \
 205         __c11_atomic_fetch_xor(object, operand, order)
 206 #define atomic_load_explicit(object, order)                             \
 207         __c11_atomic_load(object, order)
 208 #define atomic_store_explicit(object, desired, order)                   \
 209         __c11_atomic_store(object, desired, order)
 210 #elif defined(__GNUC_ATOMICS)
 211 #define atomic_compare_exchange_strong_explicit(object, expected,       \
 212     desired, success, failure)                                          \
 213         __atomic_compare_exchange_n(&(object)->__val, expected,         \
 214             desired, 0, success, failure)
 215 #define atomic_compare_exchange_weak_explicit(object, expected,         \
 216     desired, success, failure)                                          \
 217         __atomic_compare_exchange_n(&(object)->__val, expected,         \
 218             desired, 1, success, failure)
 219 #define atomic_exchange_explicit(object, desired, order)                \
 220         __atomic_exchange_n(&(object)->__val, desired, order)
 221 #define atomic_fetch_add_explicit(object, operand, order)               \
 222         __atomic_fetch_add(&(object)->__val, operand, order)
 223 #define atomic_fetch_and_explicit(object, operand, order)               \
 224         __atomic_fetch_and(&(object)->__val, operand, order)
 225 #define atomic_fetch_or_explicit(object, operand, order)                \
 226         __atomic_fetch_or(&(object)->__val, operand, order)
 227 #define atomic_fetch_sub_explicit(object, operand, order)               \
 228         __atomic_fetch_sub(&(object)->__val, operand, order)
 229 #define atomic_fetch_xor_explicit(object, operand, order)               \
 230         __atomic_fetch_xor(&(object)->__val, operand, order)
 231 #define atomic_load_explicit(object, order)                             \
 232         __atomic_load_n(&(object)->__val, order)
 233 #define atomic_store_explicit(object, desired, order)                   \
 234         __atomic_store_n(&(object)->__val, desired, order)
 235 #else
 236 #define atomic_compare_exchange_strong_explicit(object, expected,       \
 237     desired, success, failure) ({                                       \
 238         __typeof__((object)->__val) __v;                                \
 239         _Bool __r;                                                      \
 240         __v = __sync_val_compare_and_swap(&(object)->__val,             \
 241             *(expected), desired);                                      \
 242         __r = *(expected) == __v;                                       \
 243         *(expected) = __v;                                              \
 244         __r;                                                            \
 245 })
 246
 247 #define atomic_compare_exchange_weak_explicit(object, expected,         \
 248     desired, success, failure)                                          \
 249         atomic_compare_exchange_strong_explicit(object, expected,       \
 250                 desired, success, failure)
 251 #if __has_builtin(__sync_swap)
 252 /* Clang provides a full-barrier atomic exchange - use it if available. */
 253 #define atomic_exchange_explicit(object, desired, order)                \
 254         __sync_swap(&(object)->__val, desired)
 255 #else
 256 /*
 257  * __sync_lock_test_and_set() is only an acquire barrier in theory (although in
 258  * practice it is usually a full barrier) so we need an explicit barrier after
 259  * it.
 260  */
 261 #define atomic_exchange_explicit(object, desired, order) ({             \
 262         __typeof__((object)->__val) __v;                                \
 263         __v = __sync_lock_test_and_set(&(object)->__val, desired);      \
 264         __sync_synchronize();                                           \
 265         __v;                                                            \
 266 })
 267 #endif
 268 #define atomic_fetch_add_explicit(object, operand, order)               \
 269         __sync_fetch_and_add(&(object)->__val, operand)
 270 #define atomic_fetch_and_explicit(object, operand, order)               \
 271         __sync_fetch_and_and(&(object)->__val, operand)
 272 #define atomic_fetch_or_explicit(object, operand, order)                \
 273         __sync_fetch_and_or(&(object)->__val, operand)
 274 #define atomic_fetch_sub_explicit(object, operand, order)               \
 275         __sync_fetch_and_sub(&(object)->__val, operand)
 276 #define atomic_fetch_xor_explicit(object, operand, order)               \
 277         __sync_fetch_and_xor(&(object)->__val, operand)
 278 #define atomic_load_explicit(object, order)                             \
 279         __sync_fetch_and_add(&(object)->__val, 0)
 280 #define atomic_store_explicit(object, desired, order) do {              \
 281         __sync_synchronize();                                           \
 282         (object)->__val = (desired);                                    \
 283         __sync_synchronize();                                           \
 284 } while (0)
 285 #endif
 286
 287 /*
 288  * Convenience functions.
 289  */
 290
 291 #define atomic_compare_exchange_strong(object, expected, desired)       \
 292         atomic_compare_exchange_strong_explicit(object, expected,       \
 293             desired, memory_order_seq_cst, memory_order_seq_cst)
 294 #define atomic_compare_exchange_weak(object, expected, desired)         \
 295         atomic_compare_exchange_weak_explicit(object, expected,         \
 296             desired, memory_order_seq_cst, memory_order_seq_cst)
 297 #define atomic_exchange(object, desired)                                \
 298         atomic_exchange_explicit(object, desired, memory_order_seq_cst)
 299 #define atomic_fetch_add(object, operand)                               \
 300         atomic_fetch_add_explicit(object, operand, memory_order_seq_cst)
 301 #define atomic_fetch_and(object, operand)                               \
 302         atomic_fetch_and_explicit(object, operand, memory_order_seq_cst)
 303 #define atomic_fetch_or(object, operand)                                \
 304         atomic_fetch_or_explicit(object, operand, memory_order_seq_cst)
 305 #define atomic_fetch_sub(object, operand)                               \
 306         atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst)
 307 #define atomic_fetch_xor(object, operand)                               \
 308         atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst)
 309 #define atomic_load(object)                                             \
 310         atomic_load_explicit(object, memory_order_seq_cst)
 311 #define atomic_store(object, desired)                                   \
 312         atomic_store_explicit(object, desired, memory_order_seq_cst)
 313
 314 /*
 315  * 7.17.8 Atomic flag type and operations.
 316  */
 317
 318 typedef atomic_bool                     atomic_flag;
 319
 320 #define ATOMIC_FLAG_INIT                ATOMIC_VAR_INIT(0)
 321
 322 #define atomic_flag_clear_explicit(object, order)                       \
 323         atomic_store_explicit(object, 0, order)
 324 #define atomic_flag_test_and_set_explicit(object, order)                \
 325         atomic_exchange_explicit(object, 1, order)
 326
 327 #define atomic_flag_clear(object)                                       \
 328         atomic_flag_clear_explicit(object, memory_order_seq_cst)
 329 #define atomic_flag_test_and_set(object)                                \
 330         atomic_flag_test_and_set_explicit(object, memory_order_seq_cst)
 331
 332 #endif /* !_STDATOMIC_H_ */