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 35 36#if defined(__cplusplus) && defined(_USING_LIBCXX) 37# ifdef __clang__ 38# if __has_feature(cxx_atomic) 39# define _STDATOMIC_HAVE_ATOMIC 40# endif 41# else /* gcc */ 42# if __GNUC_PREREQ(4, 7) 43# define _STDATOMIC_HAVE_ATOMIC 44# endif 45# endif 46#endif 47 48#ifdef _STDATOMIC_HAVE_ATOMIC 49 50/* We have a usable C++ <atomic>; use it instead. */ 51 52#include <atomic> 53 54#undef _Atomic 55 /* Also defined by <atomic> for gcc. But not used in macros. */ 56 /* Also a clang intrinsic. */ 57 /* Should not be used by client code before this file is */ 58 /* included. The definitions in <atomic> themselves see */ 59 /* the old definition, as they should. */ 60 /* Client code sees the following definition. */ 61 62#define _Atomic(t) std::atomic<t> 63 64using std::atomic_is_lock_free; 65using std::atomic_init; 66using std::atomic_store; 67using std::atomic_store_explicit; 68using std::atomic_load; 69using std::atomic_load_explicit; 70using std::atomic_exchange; 71using std::atomic_exchange_explicit; 72using std::atomic_compare_exchange_strong; 73using std::atomic_compare_exchange_strong_explicit; 74using std::atomic_compare_exchange_weak; 75using std::atomic_compare_exchange_weak_explicit; 76using std::atomic_fetch_add; 77using std::atomic_fetch_add_explicit; 78using std::atomic_fetch_sub; 79using std::atomic_fetch_sub_explicit; 80using std::atomic_fetch_or; 81using std::atomic_fetch_or_explicit; 82using std::atomic_fetch_xor; 83using std::atomic_fetch_xor_explicit; 84using std::atomic_fetch_and; 85using std::atomic_fetch_and_explicit; 86using std::atomic_thread_fence; 87using std::atomic_signal_fence; 88 89using std::memory_order; 90using std::memory_order_relaxed; 91using std::memory_order_consume; 92using std::memory_order_release; 93using std::memory_order_acq_rel; 94using std::memory_order_seq_cst; 95 96using std::atomic_bool; 97using std::atomic_char; 98using std::atomic_schar; 99using std::atomic_uchar; 100using std::atomic_short; 101using std::atomic_ushort; 102using std::atomic_int; 103using std::atomic_uint; 104using std::atomic_long; 105using std::atomic_ulong; 106using std::atomic_llong; 107using std::atomic_ullong; 108using std::atomic_char16_t; 109using std::atomic_char32_t; 110using std::atomic_wchar_t; 111using std::atomic_int_least8_t; 112using std::atomic_uint_least8_t; 113using std::atomic_int_least16_t; 114using std::atomic_uint_least16_t; 115using std::atomic_int_least32_t; 116using std::atomic_uint_least32_t; 117using std::atomic_int_least64_t; 118using std::atomic_uint_least64_t; 119using std::atomic_int_fast8_t; 120using std::atomic_uint_fast8_t; 121using std::atomic_int_fast16_t; 122using std::atomic_uint_fast16_t; 123using std::atomic_int_fast32_t; 124using std::atomic_uint_fast32_t; 125using std::atomic_int_fast64_t; 126using std::atomic_uint_fast64_t; 127using std::atomic_intptr_t; 128using std::atomic_uintptr_t; 129using std::atomic_size_t; 130using std::atomic_ptrdiff_t; 131using std::atomic_intmax_t; 132using std::atomic_uintmax_t; 133 134#else /* <atomic> unavailable, possibly because this is C, not C++ */ 135 136#include <sys/types.h> 137#include <stdbool.h> 138 139/* 140 * C: Do it ourselves. 141 * Note that the runtime representation defined here should be compatible 142 * with the C++ one, i.e. an _Atomic(T) needs to contain the same 143 * bits as a T. 144 */ 145 146#include <stddef.h> /* For ptrdiff_t. */ 147#include <stdint.h> /* TODO: Should pollute namespace less. */ 148#if __STDC_VERSION__ >= 201112L 149# include <uchar.h> /* For char16_t and char32_t. */ 150#endif 151 152#ifdef __clang__ 153# if __has_extension(c_atomic) || __has_extension(cxx_atomic) 154# define __CLANG_ATOMICS 155# else 156# error "stdatomic.h does not support your compiler" 157# endif 158# if __has_builtin(__sync_swap) 159# define __HAS_BUILTIN_SYNC_SWAP 160# endif 161#else 162# if __GNUC_PREREQ(4, 7) 163# define __GNUC_ATOMICS 164# else 165# define __SYNC_ATOMICS 166# ifdef __cplusplus 167# define __ATOMICS_AVOID_DOT_INIT 168# endif 169# endif 170#endif 171 172/* 173 * 7.17.1 Atomic lock-free macros. 174 */ 175 176#ifdef __GCC_ATOMIC_BOOL_LOCK_FREE 177#define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE 178#elif defined(__SYNC_ATOMICS) 179#define ATOMIC_BOOL_LOCK_FREE 2 /* For all modern platforms */ 180#endif 181#ifdef __GCC_ATOMIC_CHAR_LOCK_FREE 182#define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE 183#elif defined(__SYNC_ATOMICS) 184#define ATOMIC_CHAR_LOCK_FREE 2 185#endif 186#ifdef __GCC_ATOMIC_CHAR16_T_LOCK_FREE 187#define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE 188#elif defined(__SYNC_ATOMICS) 189#define ATOMIC_CHAR16_T_LOCK_FREE 2 190#endif 191#ifdef __GCC_ATOMIC_CHAR32_T_LOCK_FREE 192#define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE 193#elif defined(__SYNC_ATOMICS) 194#define ATOMIC_CHAR32_T_LOCK_FREE 2 195#endif 196#ifdef __GCC_ATOMIC_WCHAR_T_LOCK_FREE 197#define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE 198#elif defined(__SYNC_ATOMICS) 199#define ATOMIC_WCHAR_T_LOCK_FREE 2 200#endif 201#ifdef __GCC_ATOMIC_SHORT_LOCK_FREE 202#define ATOMIC_SHORT_LOCK_FREE __GCC_ATOMIC_SHORT_LOCK_FREE 203#elif defined(__SYNC_ATOMICS) 204#define ATOMIC_SHORT_LOCK_FREE 2 205#endif 206#ifdef __GCC_ATOMIC_INT_LOCK_FREE 207#define ATOMIC_INT_LOCK_FREE __GCC_ATOMIC_INT_LOCK_FREE 208#elif defined(__SYNC_ATOMICS) 209#define ATOMIC_INT_LOCK_FREE 2 210#endif 211#ifdef __GCC_ATOMIC_LONG_LOCK_FREE 212#define ATOMIC_LONG_LOCK_FREE __GCC_ATOMIC_LONG_LOCK_FREE 213#elif defined(__SYNC_ATOMICS) 214#define ATOMIC_LONG_LOCK_FREE 2 215#endif 216#ifdef __GCC_ATOMIC_LLONG_LOCK_FREE 217#define ATOMIC_LLONG_LOCK_FREE __GCC_ATOMIC_LLONG_LOCK_FREE 218#elif defined(__SYNC_ATOMICS) 219#define ATOMIC_LLONG_LOCK_FREE 1 /* maybe */ 220#endif 221#ifdef __GCC_ATOMIC_POINTER_LOCK_FREE 222#define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE 223#elif defined(__SYNC_ATOMICS) 224#define ATOMIC_POINTER_LOCK_FREE 2 225#endif 226 227/* 228 * 7.17.2 Initialization. 229 */ 230 231#if defined(__CLANG_ATOMICS) 232#define ATOMIC_VAR_INIT(value) (value) 233#define atomic_init(obj, value) __c11_atomic_init(obj, value) 234#else 235#ifdef __ATOMICS_AVOID_DOT_INIT 236#define ATOMIC_VAR_INIT(value) { value } 237#else 238#define ATOMIC_VAR_INIT(value) { .__val = (value) } 239#endif 240#define atomic_init(obj, value) ((void)((obj)->__val = (value))) 241#endif 242 243/* 244 * Clang and recent GCC both provide predefined macros for the memory 245 * orderings. If we are using a compiler that doesn't define them, use the 246 * clang values - these will be ignored in the fallback path. 247 */ 248 249#ifndef __ATOMIC_RELAXED 250#define __ATOMIC_RELAXED 0 251#endif 252#ifndef __ATOMIC_CONSUME 253#define __ATOMIC_CONSUME 1 254#endif 255#ifndef __ATOMIC_ACQUIRE 256#define __ATOMIC_ACQUIRE 2 257#endif 258#ifndef __ATOMIC_RELEASE 259#define __ATOMIC_RELEASE 3 260#endif 261#ifndef __ATOMIC_ACQ_REL 262#define __ATOMIC_ACQ_REL 4 263#endif 264#ifndef __ATOMIC_SEQ_CST 265#define __ATOMIC_SEQ_CST 5 266#endif 267 268/* 269 * 7.17.3 Order and consistency. 270 * 271 * The memory_order_* constants that denote the barrier behaviour of the 272 * atomic operations. 273 * The enum values must be identical to those used by the 274 * C++ <atomic> header. 275 */ 276 277typedef enum { 278 memory_order_relaxed = __ATOMIC_RELAXED, 279 memory_order_consume = __ATOMIC_CONSUME, 280 memory_order_acquire = __ATOMIC_ACQUIRE, 281 memory_order_release = __ATOMIC_RELEASE, 282 memory_order_acq_rel = __ATOMIC_ACQ_REL, 283 memory_order_seq_cst = __ATOMIC_SEQ_CST 284} memory_order; 285 286/* 287 * 7.17.4 Fences. 288 */ 289 290static __inline void 291atomic_thread_fence(memory_order __order __attribute__((unused))) 292{ 293 294#ifdef __CLANG_ATOMICS 295 __c11_atomic_thread_fence(__order); 296#elif defined(__GNUC_ATOMICS) 297 __atomic_thread_fence(__order); 298#else 299 __sync_synchronize(); 300#endif 301} 302 303static __inline void 304atomic_signal_fence(memory_order __order __attribute__((unused))) 305{ 306 307#ifdef __CLANG_ATOMICS 308 __c11_atomic_signal_fence(__order); 309#elif defined(__GNUC_ATOMICS) 310 __atomic_signal_fence(__order); 311#else 312 __asm volatile ("" ::: "memory"); 313#endif 314} 315 316/* 317 * 7.17.5 Lock-free property. 318 */ 319 320#if defined(_KERNEL) 321/* Atomics in kernelspace are always lock-free. */ 322#define atomic_is_lock_free(obj) \ 323 ((void)(obj), (_Bool)1) 324#elif defined(__CLANG_ATOMICS) 325#define atomic_is_lock_free(obj) \ 326 __c11_atomic_is_lock_free(sizeof(*(obj))) 327#elif defined(__GNUC_ATOMICS) 328#define atomic_is_lock_free(obj) \ 329 __atomic_is_lock_free(sizeof((obj)->__val), &(obj)->__val) 330#else 331#define atomic_is_lock_free(obj) \ 332 ((void)(obj), sizeof((obj)->__val) <= sizeof(void *)) 333#endif 334 335/* 336 * 7.17.6 Atomic integer types. 337 */ 338 339#ifndef __CLANG_ATOMICS 340/* 341 * No native support for _Atomic(). Place object in structure to prevent 342 * most forms of direct non-atomic access. 343 */ 344#define _Atomic(T) struct { T volatile __val; } 345#endif 346 347typedef _Atomic(bool) atomic_bool; 348typedef _Atomic(char) atomic_char; 349typedef _Atomic(signed char) atomic_schar; 350typedef _Atomic(unsigned char) atomic_uchar; 351typedef _Atomic(short) atomic_short; 352typedef _Atomic(unsigned short) atomic_ushort; 353typedef _Atomic(int) atomic_int; 354typedef _Atomic(unsigned int) atomic_uint; 355typedef _Atomic(long) atomic_long; 356typedef _Atomic(unsigned long) atomic_ulong; 357typedef _Atomic(long long) atomic_llong; 358typedef _Atomic(unsigned long long) atomic_ullong; 359#if __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L 360 typedef _Atomic(char16_t) atomic_char16_t; 361 typedef _Atomic(char32_t) atomic_char32_t; 362#endif 363typedef _Atomic(wchar_t) atomic_wchar_t; 364typedef _Atomic(int_least8_t) atomic_int_least8_t; 365typedef _Atomic(uint_least8_t) atomic_uint_least8_t; 366typedef _Atomic(int_least16_t) atomic_int_least16_t; 367typedef _Atomic(uint_least16_t) atomic_uint_least16_t; 368typedef _Atomic(int_least32_t) atomic_int_least32_t; 369typedef _Atomic(uint_least32_t) atomic_uint_least32_t; 370typedef _Atomic(int_least64_t) atomic_int_least64_t; 371typedef _Atomic(uint_least64_t) atomic_uint_least64_t; 372typedef _Atomic(int_fast8_t) atomic_int_fast8_t; 373typedef _Atomic(uint_fast8_t) atomic_uint_fast8_t; 374typedef _Atomic(int_fast16_t) atomic_int_fast16_t; 375typedef _Atomic(uint_fast16_t) atomic_uint_fast16_t; 376typedef _Atomic(int_fast32_t) atomic_int_fast32_t; 377typedef _Atomic(uint_fast32_t) atomic_uint_fast32_t; 378typedef _Atomic(int_fast64_t) atomic_int_fast64_t; 379typedef _Atomic(uint_fast64_t) atomic_uint_fast64_t; 380typedef _Atomic(intptr_t) atomic_intptr_t; 381typedef _Atomic(uintptr_t) atomic_uintptr_t; 382typedef _Atomic(size_t) atomic_size_t; 383typedef _Atomic(ptrdiff_t) atomic_ptrdiff_t; 384typedef _Atomic(intmax_t) atomic_intmax_t; 385typedef _Atomic(uintmax_t) atomic_uintmax_t; 386 387/* 388 * 7.17.7 Operations on atomic types. 389 */ 390 391/* 392 * Compiler-specific operations. 393 */ 394 395#if defined(__CLANG_ATOMICS) 396#define atomic_compare_exchange_strong_explicit(object, expected, \ 397 desired, success, failure) \ 398 __c11_atomic_compare_exchange_strong(object, expected, desired, \ 399 success, failure) 400#define atomic_compare_exchange_weak_explicit(object, expected, \ 401 desired, success, failure) \ 402 __c11_atomic_compare_exchange_weak(object, expected, desired, \ 403 success, failure) 404#define atomic_exchange_explicit(object, desired, order) \ 405 __c11_atomic_exchange(object, desired, order) 406#define atomic_fetch_add_explicit(object, operand, order) \ 407 __c11_atomic_fetch_add(object, operand, order) 408#define atomic_fetch_and_explicit(object, operand, order) \ 409 __c11_atomic_fetch_and(object, operand, order) 410#define atomic_fetch_or_explicit(object, operand, order) \ 411 __c11_atomic_fetch_or(object, operand, order) 412#define atomic_fetch_sub_explicit(object, operand, order) \ 413 __c11_atomic_fetch_sub(object, operand, order) 414#define atomic_fetch_xor_explicit(object, operand, order) \ 415 __c11_atomic_fetch_xor(object, operand, order) 416#define atomic_load_explicit(object, order) \ 417 __c11_atomic_load(object, order) 418#define atomic_store_explicit(object, desired, order) \ 419 __c11_atomic_store(object, desired, order) 420#elif defined(__GNUC_ATOMICS) 421#define atomic_compare_exchange_strong_explicit(object, expected, \ 422 desired, success, failure) \ 423 __atomic_compare_exchange_n(&(object)->__val, expected, \ 424 desired, 0, success, failure) 425#define atomic_compare_exchange_weak_explicit(object, expected, \ 426 desired, success, failure) \ 427 __atomic_compare_exchange_n(&(object)->__val, expected, \ 428 desired, 1, success, failure) 429#define atomic_exchange_explicit(object, desired, order) \ 430 __atomic_exchange_n(&(object)->__val, desired, order) 431#define atomic_fetch_add_explicit(object, operand, order) \ 432 __atomic_fetch_add(&(object)->__val, operand, order) 433#define atomic_fetch_and_explicit(object, operand, order) \ 434 __atomic_fetch_and(&(object)->__val, operand, order) 435#define atomic_fetch_or_explicit(object, operand, order) \ 436 __atomic_fetch_or(&(object)->__val, operand, order) 437#define atomic_fetch_sub_explicit(object, operand, order) \ 438 __atomic_fetch_sub(&(object)->__val, operand, order) 439#define atomic_fetch_xor_explicit(object, operand, order) \ 440 __atomic_fetch_xor(&(object)->__val, operand, order) 441#define atomic_load_explicit(object, order) \ 442 __atomic_load_n(&(object)->__val, order) 443#define atomic_store_explicit(object, desired, order) \ 444 __atomic_store_n(&(object)->__val, desired, order) 445#else 446#define __atomic_apply_stride(object, operand) \ 447 (((__typeof__((object)->__val))0) + (operand)) 448#define atomic_compare_exchange_strong_explicit(object, expected, \ 449 desired, success, failure) __extension__ ({ \ 450 __typeof__(expected) __ep = (expected); \ 451 __typeof__(*__ep) __e = *__ep; \ 452 (void)(success); (void)(failure); \ 453 (bool)((*__ep = __sync_val_compare_and_swap(&(object)->__val, \ 454 __e, desired)) == __e); \ 455}) 456#define atomic_compare_exchange_weak_explicit(object, expected, \ 457 desired, success, failure) \ 458 atomic_compare_exchange_strong_explicit(object, expected, \ 459 desired, success, failure) 460#ifdef __HAS_BUILTIN_SYNC_SWAP 461/* Clang provides a full-barrier atomic exchange - use it if available. */ 462#define atomic_exchange_explicit(object, desired, order) \ 463 ((void)(order), __sync_swap(&(object)->__val, desired)) 464#else 465/* 466 * __sync_lock_test_and_set() is only an acquire barrier in theory (although in 467 * practice it is usually a full barrier) so we need an explicit barrier before 468 * it. 469 */ 470#define atomic_exchange_explicit(object, desired, order) \ 471__extension__ ({ \ 472 __typeof__(object) __o = (object); \ 473 __typeof__(desired) __d = (desired); \ 474 (void)(order); \ 475 __sync_synchronize(); \ 476 __sync_lock_test_and_set(&(__o)->__val, __d); \ 477}) 478#endif 479#define atomic_fetch_add_explicit(object, operand, order) \ 480 ((void)(order), __sync_fetch_and_add(&(object)->__val, \ 481 __atomic_apply_stride(object, operand))) 482#define atomic_fetch_and_explicit(object, operand, order) \ 483 ((void)(order), __sync_fetch_and_and(&(object)->__val, operand)) 484#define atomic_fetch_or_explicit(object, operand, order) \ 485 ((void)(order), __sync_fetch_and_or(&(object)->__val, operand)) 486#define atomic_fetch_sub_explicit(object, operand, order) \ 487 ((void)(order), __sync_fetch_and_sub(&(object)->__val, \ 488 __atomic_apply_stride(object, operand))) 489#define atomic_fetch_xor_explicit(object, operand, order) \ 490 ((void)(order), __sync_fetch_and_xor(&(object)->__val, operand)) 491#define atomic_load_explicit(object, order) \ 492 ((void)(order), __sync_fetch_and_add(&(object)->__val, 0)) 493#define atomic_store_explicit(object, desired, order) \ 494 ((void)atomic_exchange_explicit(object, desired, order)) 495#endif 496 497/* 498 * Convenience functions. 499 * 500 * Don't provide these in kernel space. In kernel space, we should be 501 * disciplined enough to always provide explicit barriers. 502 */ 503 504#ifndef _KERNEL 505#define atomic_compare_exchange_strong(object, expected, desired) \ 506 atomic_compare_exchange_strong_explicit(object, expected, \ 507 desired, memory_order_seq_cst, memory_order_seq_cst) 508#define atomic_compare_exchange_weak(object, expected, desired) \ 509 atomic_compare_exchange_weak_explicit(object, expected, \ 510 desired, memory_order_seq_cst, memory_order_seq_cst) 511#define atomic_exchange(object, desired) \ 512 atomic_exchange_explicit(object, desired, memory_order_seq_cst) 513#define atomic_fetch_add(object, operand) \ 514 atomic_fetch_add_explicit(object, operand, memory_order_seq_cst) 515#define atomic_fetch_and(object, operand) \ 516 atomic_fetch_and_explicit(object, operand, memory_order_seq_cst) 517#define atomic_fetch_or(object, operand) \ 518 atomic_fetch_or_explicit(object, operand, memory_order_seq_cst) 519#define atomic_fetch_sub(object, operand) \ 520 atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst) 521#define atomic_fetch_xor(object, operand) \ 522 atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst) 523#define atomic_load(object) \ 524 atomic_load_explicit(object, memory_order_seq_cst) 525#define atomic_store(object, desired) \ 526 atomic_store_explicit(object, desired, memory_order_seq_cst) 527#endif /* !_KERNEL */ 528 529/* 530 * 7.17.8 Atomic flag type and operations. 531 * 532 * XXX: Assume atomic_bool can be used as an atomic_flag. Is there some 533 * kind of compiler built-in type we could use? 534 */ 535 536typedef struct { 537 atomic_bool __flag; 538} atomic_flag; 539 540#define ATOMIC_FLAG_INIT { ATOMIC_VAR_INIT(false) } 541 542static __inline bool 543atomic_flag_test_and_set_explicit(volatile atomic_flag *__object, 544 memory_order __order) 545{ 546 return (atomic_exchange_explicit(&__object->__flag, 1, __order)); 547} 548 549static __inline void 550atomic_flag_clear_explicit(volatile atomic_flag *__object, memory_order __order) 551{ 552 553 atomic_store_explicit(&__object->__flag, 0, __order); 554} 555 556#ifndef _KERNEL 557static __inline bool 558atomic_flag_test_and_set(volatile atomic_flag *__object) 559{ 560 561 return (atomic_flag_test_and_set_explicit(__object, 562 memory_order_seq_cst)); 563} 564 565static __inline void 566atomic_flag_clear(volatile atomic_flag *__object) 567{ 568 569 atomic_flag_clear_explicit(__object, memory_order_seq_cst); 570} 571#endif /* !_KERNEL */ 572 573#endif /* <atomic> unavailable */ 574 575#endif /* !_STDATOMIC_H_ */ 576