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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP_ATOMIC11#define _LIBCPP_ATOMIC12 13/*14 atomic synopsis15 16namespace std17{18 19// feature test macro [version.syn]20 21#define __cpp_lib_atomic_is_always_lock_free22#define __cpp_lib_atomic_flag_test23#define __cpp_lib_atomic_lock_free_type_aliases24#define __cpp_lib_atomic_wait25 26 // order and consistency27 28 enum memory_order: unspecified // enum class in C++2029 {30 relaxed,31 consume, // load-consume32 acquire, // load-acquire33 release, // store-release34 acq_rel, // store-release load-acquire35 seq_cst // store-release load-acquire36 };37 38 inline constexpr auto memory_order_relaxed = memory_order::relaxed;39 inline constexpr auto memory_order_consume = memory_order::consume;40 inline constexpr auto memory_order_acquire = memory_order::acquire;41 inline constexpr auto memory_order_release = memory_order::release;42 inline constexpr auto memory_order_acq_rel = memory_order::acq_rel;43 inline constexpr auto memory_order_seq_cst = memory_order::seq_cst;44 45template <class T> T kill_dependency(T y) noexcept;46 47// lock-free property48 49#define ATOMIC_BOOL_LOCK_FREE unspecified50#define ATOMIC_CHAR_LOCK_FREE unspecified51#define ATOMIC_CHAR8_T_LOCK_FREE unspecified // C++2052#define ATOMIC_CHAR16_T_LOCK_FREE unspecified53#define ATOMIC_CHAR32_T_LOCK_FREE unspecified54#define ATOMIC_WCHAR_T_LOCK_FREE unspecified55#define ATOMIC_SHORT_LOCK_FREE unspecified56#define ATOMIC_INT_LOCK_FREE unspecified57#define ATOMIC_LONG_LOCK_FREE unspecified58#define ATOMIC_LLONG_LOCK_FREE unspecified59#define ATOMIC_POINTER_LOCK_FREE unspecified60 61template <class T>62struct atomic63{64 using value_type = T;65 66 static constexpr bool is_always_lock_free;67 bool is_lock_free() const volatile noexcept;68 bool is_lock_free() const noexcept;69 70 atomic() noexcept = default; // until C++2071 constexpr atomic() noexcept(is_nothrow_default_constructible_v<T>); // since C++2072 constexpr atomic(T desr) noexcept;73 atomic(const atomic&) = delete;74 atomic& operator=(const atomic&) = delete;75 atomic& operator=(const atomic&) volatile = delete;76 77 T load(memory_order m = memory_order_seq_cst) const volatile noexcept;78 T load(memory_order m = memory_order_seq_cst) const noexcept;79 operator T() const volatile noexcept;80 operator T() const noexcept;81 void store(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;82 void store(T desr, memory_order m = memory_order_seq_cst) noexcept;83 T operator=(T) volatile noexcept;84 T operator=(T) noexcept;85 86 T exchange(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;87 T exchange(T desr, memory_order m = memory_order_seq_cst) noexcept;88 bool compare_exchange_weak(T& expc, T desr,89 memory_order s, memory_order f) volatile noexcept;90 bool compare_exchange_weak(T& expc, T desr, memory_order s, memory_order f) noexcept;91 bool compare_exchange_strong(T& expc, T desr,92 memory_order s, memory_order f) volatile noexcept;93 bool compare_exchange_strong(T& expc, T desr,94 memory_order s, memory_order f) noexcept;95 bool compare_exchange_weak(T& expc, T desr,96 memory_order m = memory_order_seq_cst) volatile noexcept;97 bool compare_exchange_weak(T& expc, T desr,98 memory_order m = memory_order_seq_cst) noexcept;99 bool compare_exchange_strong(T& expc, T desr,100 memory_order m = memory_order_seq_cst) volatile noexcept;101 bool compare_exchange_strong(T& expc, T desr,102 memory_order m = memory_order_seq_cst) noexcept;103 104 void wait(T, memory_order = memory_order::seq_cst) const volatile noexcept; // since C++20105 void wait(T, memory_order = memory_order::seq_cst) const noexcept; // since C++20106 void notify_one() volatile noexcept; // since C++20107 void notify_one() noexcept; // since C++20108 void notify_all() volatile noexcept; // since C++20109 void notify_all() noexcept; // since C++20110};111 112template <>113struct atomic<integral>114{115 using value_type = integral;116 using difference_type = value_type;117 118 static constexpr bool is_always_lock_free;119 bool is_lock_free() const volatile noexcept;120 bool is_lock_free() const noexcept;121 122 atomic() noexcept = default;123 constexpr atomic(integral desr) noexcept;124 atomic(const atomic&) = delete;125 atomic& operator=(const atomic&) = delete;126 atomic& operator=(const atomic&) volatile = delete;127 128 integral load(memory_order m = memory_order_seq_cst) const volatile noexcept;129 integral load(memory_order m = memory_order_seq_cst) const noexcept;130 operator integral() const volatile noexcept;131 operator integral() const noexcept;132 void store(integral desr, memory_order m = memory_order_seq_cst) volatile noexcept;133 void store(integral desr, memory_order m = memory_order_seq_cst) noexcept;134 integral operator=(integral desr) volatile noexcept;135 integral operator=(integral desr) noexcept;136 137 integral exchange(integral desr,138 memory_order m = memory_order_seq_cst) volatile noexcept;139 integral exchange(integral desr, memory_order m = memory_order_seq_cst) noexcept;140 bool compare_exchange_weak(integral& expc, integral desr,141 memory_order s, memory_order f) volatile noexcept;142 bool compare_exchange_weak(integral& expc, integral desr,143 memory_order s, memory_order f) noexcept;144 bool compare_exchange_strong(integral& expc, integral desr,145 memory_order s, memory_order f) volatile noexcept;146 bool compare_exchange_strong(integral& expc, integral desr,147 memory_order s, memory_order f) noexcept;148 bool compare_exchange_weak(integral& expc, integral desr,149 memory_order m = memory_order_seq_cst) volatile noexcept;150 bool compare_exchange_weak(integral& expc, integral desr,151 memory_order m = memory_order_seq_cst) noexcept;152 bool compare_exchange_strong(integral& expc, integral desr,153 memory_order m = memory_order_seq_cst) volatile noexcept;154 bool compare_exchange_strong(integral& expc, integral desr,155 memory_order m = memory_order_seq_cst) noexcept;156 157 integral fetch_add(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;158 integral fetch_add(integral op, memory_order m = memory_order_seq_cst) noexcept;159 integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;160 integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) noexcept;161 integral fetch_and(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;162 integral fetch_and(integral op, memory_order m = memory_order_seq_cst) noexcept;163 integral fetch_or(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;164 integral fetch_or(integral op, memory_order m = memory_order_seq_cst) noexcept;165 integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;166 integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) noexcept;167 168 integral operator++(int) volatile noexcept;169 integral operator++(int) noexcept;170 integral operator--(int) volatile noexcept;171 integral operator--(int) noexcept;172 integral operator++() volatile noexcept;173 integral operator++() noexcept;174 integral operator--() volatile noexcept;175 integral operator--() noexcept;176 integral operator+=(integral op) volatile noexcept;177 integral operator+=(integral op) noexcept;178 integral operator-=(integral op) volatile noexcept;179 integral operator-=(integral op) noexcept;180 integral operator&=(integral op) volatile noexcept;181 integral operator&=(integral op) noexcept;182 integral operator|=(integral op) volatile noexcept;183 integral operator|=(integral op) noexcept;184 integral operator^=(integral op) volatile noexcept;185 integral operator^=(integral op) noexcept;186 187 void wait(integral, memory_order = memory_order::seq_cst) const volatile noexcept; // since C++20188 void wait(integral, memory_order = memory_order::seq_cst) const noexcept; // since C++20189 void notify_one() volatile noexcept; // since C++20190 void notify_one() noexcept; // since C++20191 void notify_all() volatile noexcept; // since C++20192 void notify_all() noexcept; // since C++20193};194 195template <class T>196struct atomic<T*>197{198 using value_type = T*;199 using difference_type = ptrdiff_t;200 201 static constexpr bool is_always_lock_free;202 bool is_lock_free() const volatile noexcept;203 bool is_lock_free() const noexcept;204 205 atomic() noexcept = default; // until C++20206 constexpr atomic() noexcept; // since C++20207 constexpr atomic(T* desr) noexcept;208 atomic(const atomic&) = delete;209 atomic& operator=(const atomic&) = delete;210 atomic& operator=(const atomic&) volatile = delete;211 212 T* load(memory_order m = memory_order_seq_cst) const volatile noexcept;213 T* load(memory_order m = memory_order_seq_cst) const noexcept;214 operator T*() const volatile noexcept;215 operator T*() const noexcept;216 void store(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;217 void store(T* desr, memory_order m = memory_order_seq_cst) noexcept;218 T* operator=(T*) volatile noexcept;219 T* operator=(T*) noexcept;220 221 T* exchange(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;222 T* exchange(T* desr, memory_order m = memory_order_seq_cst) noexcept;223 bool compare_exchange_weak(T*& expc, T* desr,224 memory_order s, memory_order f) volatile noexcept;225 bool compare_exchange_weak(T*& expc, T* desr,226 memory_order s, memory_order f) noexcept;227 bool compare_exchange_strong(T*& expc, T* desr,228 memory_order s, memory_order f) volatile noexcept;229 bool compare_exchange_strong(T*& expc, T* desr,230 memory_order s, memory_order f) noexcept;231 bool compare_exchange_weak(T*& expc, T* desr,232 memory_order m = memory_order_seq_cst) volatile noexcept;233 bool compare_exchange_weak(T*& expc, T* desr,234 memory_order m = memory_order_seq_cst) noexcept;235 bool compare_exchange_strong(T*& expc, T* desr,236 memory_order m = memory_order_seq_cst) volatile noexcept;237 bool compare_exchange_strong(T*& expc, T* desr,238 memory_order m = memory_order_seq_cst) noexcept;239 T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;240 T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;241 T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;242 T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;243 244 T* operator++(int) volatile noexcept;245 T* operator++(int) noexcept;246 T* operator--(int) volatile noexcept;247 T* operator--(int) noexcept;248 T* operator++() volatile noexcept;249 T* operator++() noexcept;250 T* operator--() volatile noexcept;251 T* operator--() noexcept;252 T* operator+=(ptrdiff_t op) volatile noexcept;253 T* operator+=(ptrdiff_t op) noexcept;254 T* operator-=(ptrdiff_t op) volatile noexcept;255 T* operator-=(ptrdiff_t op) noexcept;256 257 void wait(T*, memory_order = memory_order::seq_cst) const volatile noexcept; // since C++20258 void wait(T*, memory_order = memory_order::seq_cst) const noexcept; // since C++20259 void notify_one() volatile noexcept; // since C++20260 void notify_one() noexcept; // since C++20261 void notify_all() volatile noexcept; // since C++20262 void notify_all() noexcept; // since C++20263};264 265template<>266struct atomic<floating-point-type> { // since C++20267 using value_type = floating-point-type;268 using difference_type = value_type;269 270 static constexpr bool is_always_lock_free = implementation-defined;271 bool is_lock_free() const volatile noexcept;272 bool is_lock_free() const noexcept;273 274 constexpr atomic() noexcept;275 constexpr atomic(floating-point-type) noexcept;276 atomic(const atomic&) = delete;277 atomic& operator=(const atomic&) = delete;278 atomic& operator=(const atomic&) volatile = delete;279 280 void store(floating-point-type, memory_order = memory_order::seq_cst) volatile noexcept;281 void store(floating-point-type, memory_order = memory_order::seq_cst) noexcept;282 floating-point-type operator=(floating-point-type) volatile noexcept;283 floating-point-type operator=(floating-point-type) noexcept;284 floating-point-type load(memory_order = memory_order::seq_cst) volatile noexcept;285 floating-point-type load(memory_order = memory_order::seq_cst) noexcept;286 operator floating-point-type() volatile noexcept;287 operator floating-point-type() noexcept;288 289 floating-point-type exchange(floating-point-type,290 memory_order = memory_order::seq_cst) volatile noexcept;291 floating-point-type exchange(floating-point-type,292 memory_order = memory_order::seq_cst) noexcept;293 bool compare_exchange_weak(floating-point-type&, floating-point-type,294 memory_order, memory_order) volatile noexcept;295 bool compare_exchange_weak(floating-point-type&, floating-point-type,296 memory_order, memory_order) noexcept;297 bool compare_exchange_strong(floating-point-type&, floating-point-type,298 memory_order, memory_order) volatile noexcept;299 bool compare_exchange_strong(floating-point-type&, floating-point-type,300 memory_order, memory_order) noexcept;301 bool compare_exchange_weak(floating-point-type&, floating-point-type,302 memory_order = memory_order::seq_cst) volatile noexcept;303 bool compare_exchange_weak(floating-point-type&, floating-point-type,304 memory_order = memory_order::seq_cst) noexcept;305 bool compare_exchange_strong(floating-point-type&, floating-point-type,306 memory_order = memory_order::seq_cst) volatile noexcept;307 bool compare_exchange_strong(floating-point-type&, floating-point-type,308 memory_order = memory_order::seq_cst) noexcept;309 310 floating-point-type fetch_add(floating-point-type,311 memory_order = memory_order::seq_cst) volatile noexcept;312 floating-point-type fetch_add(floating-point-type,313 memory_order = memory_order::seq_cst) noexcept;314 floating-point-type fetch_sub(floating-point-type,315 memory_order = memory_order::seq_cst) volatile noexcept;316 floating-point-type fetch_sub(floating-point-type,317 memory_order = memory_order::seq_cst) noexcept;318 319 floating-point-type operator+=(floating-point-type) volatile noexcept;320 floating-point-type operator+=(floating-point-type) noexcept;321 floating-point-type operator-=(floating-point-type) volatile noexcept;322 floating-point-type operator-=(floating-point-type) noexcept;323 324 void wait(floating-point-type, memory_order = memory_order::seq_cst) const volatile noexcept; // since C++20325 void wait(floating-point-type, memory_order = memory_order::seq_cst) const noexcept; // since C++20326 void notify_one() volatile noexcept; // since C++20327 void notify_one() noexcept; // since C++20328 void notify_all() volatile noexcept; // since C++20329 void notify_all() noexcept; // since C++20330};331 332// [atomics.nonmembers], non-member functions333template<class T>334 bool atomic_is_lock_free(const volatile atomic<T>*) noexcept;335template<class T>336 bool atomic_is_lock_free(const atomic<T>*) noexcept;337template<class T>338 void atomic_store(volatile atomic<T>*, atomic<T>::value_type) noexcept;339template<class T>340 void atomic_store(atomic<T>*, atomic<T>::value_type) noexcept;341template<class T>342 void atomic_store_explicit(volatile atomic<T>*, atomic<T>::value_type,343 memory_order) noexcept;344template<class T>345 void atomic_store_explicit(atomic<T>*, atomic<T>::value_type,346 memory_order) noexcept;347template<class T>348 T atomic_load(const volatile atomic<T>*) noexcept;349template<class T>350 T atomic_load(const atomic<T>*) noexcept;351template<class T>352 T atomic_load_explicit(const volatile atomic<T>*, memory_order) noexcept;353template<class T>354 T atomic_load_explicit(const atomic<T>*, memory_order) noexcept;355template<class T>356 T atomic_exchange(volatile atomic<T>*, atomic<T>::value_type) noexcept;357template<class T>358 T atomic_exchange(atomic<T>*, atomic<T>::value_type) noexcept;359template<class T>360 T atomic_exchange_explicit(volatile atomic<T>*, atomic<T>::value_type,361 memory_order) noexcept;362template<class T>363 T atomic_exchange_explicit(atomic<T>*, atomic<T>::value_type,364 memory_order) noexcept;365template<class T>366 bool atomic_compare_exchange_weak(volatile atomic<T>*, atomic<T>::value_type*,367 atomic<T>::value_type) noexcept;368template<class T>369 bool atomic_compare_exchange_weak(atomic<T>*, atomic<T>::value_type*,370 atomic<T>::value_type) noexcept;371template<class T>372 bool atomic_compare_exchange_strong(volatile atomic<T>*, atomic<T>::value_type*,373 atomic<T>::value_type) noexcept;374template<class T>375 bool atomic_compare_exchange_strong(atomic<T>*, atomic<T>::value_type*,376 atomic<T>::value_type) noexcept;377template<class T>378 bool atomic_compare_exchange_weak_explicit(volatile atomic<T>*, atomic<T>::value_type*,379 atomic<T>::value_type,380 memory_order, memory_order) noexcept;381template<class T>382 bool atomic_compare_exchange_weak_explicit(atomic<T>*, atomic<T>::value_type*,383 atomic<T>::value_type,384 memory_order, memory_order) noexcept;385template<class T>386 bool atomic_compare_exchange_strong_explicit(volatile atomic<T>*, atomic<T>::value_type*,387 atomic<T>::value_type,388 memory_order, memory_order) noexcept;389template<class T>390 bool atomic_compare_exchange_strong_explicit(atomic<T>*, atomic<T>::value_type*,391 atomic<T>::value_type,392 memory_order, memory_order) noexcept;393 394template<class T>395 T atomic_fetch_add(volatile atomic<T>*, atomic<T>::difference_type) noexcept;396template<class T>397 T atomic_fetch_add(atomic<T>*, atomic<T>::difference_type) noexcept;398template<class T>399 T atomic_fetch_add_explicit(volatile atomic<T>*, atomic<T>::difference_type,400 memory_order) noexcept;401template<class T>402 T atomic_fetch_add_explicit(atomic<T>*, atomic<T>::difference_type,403 memory_order) noexcept;404template<class T>405 T atomic_fetch_sub(volatile atomic<T>*, atomic<T>::difference_type) noexcept;406template<class T>407 T atomic_fetch_sub(atomic<T>*, atomic<T>::difference_type) noexcept;408template<class T>409 T atomic_fetch_sub_explicit(volatile atomic<T>*, atomic<T>::difference_type,410 memory_order) noexcept;411template<class T>412 T atomic_fetch_sub_explicit(atomic<T>*, atomic<T>::difference_type,413 memory_order) noexcept;414template<class T>415 T atomic_fetch_and(volatile atomic<T>*, atomic<T>::value_type) noexcept;416template<class T>417 T atomic_fetch_and(atomic<T>*, atomic<T>::value_type) noexcept;418template<class T>419 T atomic_fetch_and_explicit(volatile atomic<T>*, atomic<T>::value_type,420 memory_order) noexcept;421template<class T>422 T atomic_fetch_and_explicit(atomic<T>*, atomic<T>::value_type,423 memory_order) noexcept;424template<class T>425 T atomic_fetch_or(volatile atomic<T>*, atomic<T>::value_type) noexcept;426template<class T>427 T atomic_fetch_or(atomic<T>*, atomic<T>::value_type) noexcept;428template<class T>429 T atomic_fetch_or_explicit(volatile atomic<T>*, atomic<T>::value_type,430 memory_order) noexcept;431template<class T>432 T atomic_fetch_or_explicit(atomic<T>*, atomic<T>::value_type,433 memory_order) noexcept;434template<class T>435 T atomic_fetch_xor(volatile atomic<T>*, atomic<T>::value_type) noexcept;436template<class T>437 T atomic_fetch_xor(atomic<T>*, atomic<T>::value_type) noexcept;438template<class T>439 T atomic_fetch_xor_explicit(volatile atomic<T>*, atomic<T>::value_type,440 memory_order) noexcept;441template<class T>442 T atomic_fetch_xor_explicit(atomic<T>*, atomic<T>::value_type,443 memory_order) noexcept;444 445template<class T>446 void atomic_wait(const volatile atomic<T>*, atomic<T>::value_type) noexcept; // since C++20447template<class T>448 void atomic_wait(const atomic<T>*, atomic<T>::value_type) noexcept; // since C++20449template<class T>450 void atomic_wait_explicit(const volatile atomic<T>*, atomic<T>::value_type, // since C++20451 memory_order) noexcept;452template<class T>453 void atomic_wait_explicit(const atomic<T>*, atomic<T>::value_type, // since C++20454 memory_order) noexcept;455template<class T>456 void atomic_notify_one(volatile atomic<T>*) noexcept; // since C++20457template<class T>458 void atomic_notify_one(atomic<T>*) noexcept; // since C++20459template<class T>460 void atomic_notify_all(volatile atomic<T>*) noexcept; // since C++20461template<class T>462 void atomic_notify_all(atomic<T>*) noexcept; // since C++20463 464// Atomics for standard typedef types465 466typedef atomic<bool> atomic_bool;467typedef atomic<char> atomic_char;468typedef atomic<signed char> atomic_schar;469typedef atomic<unsigned char> atomic_uchar;470typedef atomic<short> atomic_short;471typedef atomic<unsigned short> atomic_ushort;472typedef atomic<int> atomic_int;473typedef atomic<unsigned int> atomic_uint;474typedef atomic<long> atomic_long;475typedef atomic<unsigned long> atomic_ulong;476typedef atomic<long long> atomic_llong;477typedef atomic<unsigned long long> atomic_ullong;478typedef atomic<char8_t> atomic_char8_t; // C++20479typedef atomic<char16_t> atomic_char16_t;480typedef atomic<char32_t> atomic_char32_t;481typedef atomic<wchar_t> atomic_wchar_t;482 483typedef atomic<int_least8_t> atomic_int_least8_t;484typedef atomic<uint_least8_t> atomic_uint_least8_t;485typedef atomic<int_least16_t> atomic_int_least16_t;486typedef atomic<uint_least16_t> atomic_uint_least16_t;487typedef atomic<int_least32_t> atomic_int_least32_t;488typedef atomic<uint_least32_t> atomic_uint_least32_t;489typedef atomic<int_least64_t> atomic_int_least64_t;490typedef atomic<uint_least64_t> atomic_uint_least64_t;491 492typedef atomic<int_fast8_t> atomic_int_fast8_t;493typedef atomic<uint_fast8_t> atomic_uint_fast8_t;494typedef atomic<int_fast16_t> atomic_int_fast16_t;495typedef atomic<uint_fast16_t> atomic_uint_fast16_t;496typedef atomic<int_fast32_t> atomic_int_fast32_t;497typedef atomic<uint_fast32_t> atomic_uint_fast32_t;498typedef atomic<int_fast64_t> atomic_int_fast64_t;499typedef atomic<uint_fast64_t> atomic_uint_fast64_t;500 501typedef atomic<int8_t> atomic_int8_t;502typedef atomic<uint8_t> atomic_uint8_t;503typedef atomic<int16_t> atomic_int16_t;504typedef atomic<uint16_t> atomic_uint16_t;505typedef atomic<int32_t> atomic_int32_t;506typedef atomic<uint32_t> atomic_uint32_t;507typedef atomic<int64_t> atomic_int64_t;508typedef atomic<uint64_t> atomic_uint64_t;509 510typedef atomic<intptr_t> atomic_intptr_t;511typedef atomic<uintptr_t> atomic_uintptr_t;512typedef atomic<size_t> atomic_size_t;513typedef atomic<ptrdiff_t> atomic_ptrdiff_t;514typedef atomic<intmax_t> atomic_intmax_t;515typedef atomic<uintmax_t> atomic_uintmax_t;516 517typedef see-below atomic_signed_lock_free; // since C++20518typedef see-below atomic_unsigned_lock_free; // since C++20519 520// flag type and operations521 522typedef struct atomic_flag523{524 atomic_flag() noexcept = default; // until C++20525 constexpr atomic_flag() noexcept; // since C++20526 atomic_flag(const atomic_flag&) = delete;527 atomic_flag& operator=(const atomic_flag&) = delete;528 atomic_flag& operator=(const atomic_flag&) volatile = delete;529 530 bool test(memory_order m = memory_order_seq_cst) volatile noexcept;531 bool test(memory_order m = memory_order_seq_cst) noexcept;532 bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept;533 bool test_and_set(memory_order m = memory_order_seq_cst) noexcept;534 void clear(memory_order m = memory_order_seq_cst) volatile noexcept;535 void clear(memory_order m = memory_order_seq_cst) noexcept;536 537 void wait(bool, memory_order = memory_order::seq_cst) const volatile noexcept; // since C++20538 void wait(bool, memory_order = memory_order::seq_cst) const noexcept; // since C++20539 void notify_one() volatile noexcept; // since C++20540 void notify_one() noexcept; // since C++20541 void notify_all() volatile noexcept; // since C++20542 void notify_all() noexcept; // since C++20543} atomic_flag;544 545bool atomic_flag_test(volatile atomic_flag* obj) noexcept;546bool atomic_flag_test(atomic_flag* obj) noexcept;547bool atomic_flag_test_explicit(volatile atomic_flag* obj,548 memory_order m) noexcept;549bool atomic_flag_test_explicit(atomic_flag* obj, memory_order m) noexcept;550bool atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept;551bool atomic_flag_test_and_set(atomic_flag* obj) noexcept;552bool atomic_flag_test_and_set_explicit(volatile atomic_flag* obj,553 memory_order m) noexcept;554bool atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept;555void atomic_flag_clear(volatile atomic_flag* obj) noexcept;556void atomic_flag_clear(atomic_flag* obj) noexcept;557void atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept;558void atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept;559 560void atomic_wait(const volatile atomic_flag* obj, T old) noexcept; // since C++20561void atomic_wait(const atomic_flag* obj, T old) noexcept; // since C++20562void atomic_wait_explicit(const volatile atomic_flag* obj, T old, memory_order m) noexcept; // since C++20563void atomic_wait_explicit(const atomic_flag* obj, T old, memory_order m) noexcept; // since C++20564void atomic_one(volatile atomic_flag* obj) noexcept; // since C++20565void atomic_one(atomic_flag* obj) noexcept; // since C++20566void atomic_all(volatile atomic_flag* obj) noexcept; // since C++20567void atomic_all(atomic_flag* obj) noexcept; // since C++20568 569// fences570 571void atomic_thread_fence(memory_order m) noexcept;572void atomic_signal_fence(memory_order m) noexcept;573 574// deprecated575 576template <class T>577 void atomic_init(volatile atomic<T>* obj, atomic<T>::value_type desr) noexcept;578 579template <class T>580 void atomic_init(atomic<T>* obj, atomic<T>::value_type desr) noexcept;581 582#define ATOMIC_VAR_INIT(value) see below583 584#define ATOMIC_FLAG_INIT see below585 586} // std587 588*/589 590#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)591# include <__cxx03/atomic>592#else593# include <__config>594 595# if defined(_LIBCPP_STDATOMIC_H) || defined(kill_dependency) || defined(atomic_load)596# define _LIBCPP_STDATOMIC_H_HAS_DEFINITELY_BEEN_INCLUDED 1597# else598# define _LIBCPP_STDATOMIC_H_HAS_DEFINITELY_BEEN_INCLUDED 0599# endif600 601# if _LIBCPP_STD_VER < 23 && _LIBCPP_STDATOMIC_H_HAS_DEFINITELY_BEEN_INCLUDED602# error <atomic> is incompatible with <stdatomic.h> before C++23. Please compile with -std=c++23.603# endif604 605# include <__atomic/aliases.h>606# include <__atomic/atomic.h>607# include <__atomic/atomic_flag.h>608# include <__atomic/atomic_init.h>609# include <__atomic/atomic_lock_free.h>610# include <__atomic/atomic_sync.h>611# include <__atomic/check_memory_order.h>612# include <__atomic/contention_t.h>613# include <__atomic/fence.h>614# include <__atomic/is_always_lock_free.h>615# include <__atomic/kill_dependency.h>616# include <__atomic/memory_order.h>617# include <version>618 619# if _LIBCPP_STD_VER >= 20620# include <__atomic/atomic_ref.h>621# endif622 623# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)624# pragma GCC system_header625# endif626 627# if !_LIBCPP_HAS_ATOMIC_HEADER628# error <atomic> is not implemented629# endif630 631# if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20632# include <cmath>633# include <compare>634# include <cstddef>635# include <cstdlib>636# include <cstring>637# include <type_traits>638# endif639#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)640 641#endif // _LIBCPP_ATOMIC642