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      1 // -*- C++ -*-
      2 //===--------------------------- atomic -----------------------------------===//
      3 //
      4 //                     The LLVM Compiler Infrastructure
      5 //
      6 // This file is distributed under the University of Illinois Open Source
      7 // License. See LICENSE.TXT for details.
      8 //
      9 //===----------------------------------------------------------------------===//
     10 
     11 #ifndef _LIBCPP_ATOMIC
     12 #define _LIBCPP_ATOMIC
     13 
     14 /*
     15     atomic synopsis
     16 
     17 namespace std
     18 {
     19 
     20 // feature test macro
     21 
     22 #define __cpp_lib_atomic_is_always_lock_free // as specified by SG10
     23 
     24 // order and consistency
     25 
     26 typedef enum memory_order
     27 {
     28     memory_order_relaxed,
     29     memory_order_consume,  // load-consume
     30     memory_order_acquire,  // load-acquire
     31     memory_order_release,  // store-release
     32     memory_order_acq_rel,  // store-release load-acquire
     33     memory_order_seq_cst   // store-release load-acquire
     34 } memory_order;
     35 
     36 template <class T> T kill_dependency(T y) noexcept;
     37 
     38 // lock-free property
     39 
     40 #define ATOMIC_BOOL_LOCK_FREE unspecified
     41 #define ATOMIC_CHAR_LOCK_FREE unspecified
     42 #define ATOMIC_CHAR16_T_LOCK_FREE unspecified
     43 #define ATOMIC_CHAR32_T_LOCK_FREE unspecified
     44 #define ATOMIC_WCHAR_T_LOCK_FREE unspecified
     45 #define ATOMIC_SHORT_LOCK_FREE unspecified
     46 #define ATOMIC_INT_LOCK_FREE unspecified
     47 #define ATOMIC_LONG_LOCK_FREE unspecified
     48 #define ATOMIC_LLONG_LOCK_FREE unspecified
     49 #define ATOMIC_POINTER_LOCK_FREE unspecified
     50 
     51 // flag type and operations
     52 
     53 typedef struct atomic_flag
     54 {
     55     bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept;
     56     bool test_and_set(memory_order m = memory_order_seq_cst) noexcept;
     57     void clear(memory_order m = memory_order_seq_cst) volatile noexcept;
     58     void clear(memory_order m = memory_order_seq_cst) noexcept;
     59     atomic_flag()  noexcept = default;
     60     atomic_flag(const atomic_flag&) = delete;
     61     atomic_flag& operator=(const atomic_flag&) = delete;
     62     atomic_flag& operator=(const atomic_flag&) volatile = delete;
     63 } atomic_flag;
     64 
     65 bool
     66     atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept;
     67 
     68 bool
     69     atomic_flag_test_and_set(atomic_flag* obj) noexcept;
     70 
     71 bool
     72     atomic_flag_test_and_set_explicit(volatile atomic_flag* obj,
     73                                       memory_order m) noexcept;
     74 
     75 bool
     76     atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept;
     77 
     78 void
     79     atomic_flag_clear(volatile atomic_flag* obj) noexcept;
     80 
     81 void
     82     atomic_flag_clear(atomic_flag* obj) noexcept;
     83 
     84 void
     85     atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept;
     86 
     87 void
     88     atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept;
     89 
     90 #define ATOMIC_FLAG_INIT see below
     91 #define ATOMIC_VAR_INIT(value) see below
     92 
     93 template <class T>
     94 struct atomic
     95 {
     96     static constexpr bool is_always_lock_free;
     97     bool is_lock_free() const volatile noexcept;
     98     bool is_lock_free() const noexcept;
     99     void store(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
    100     void store(T desr, memory_order m = memory_order_seq_cst) noexcept;
    101     T load(memory_order m = memory_order_seq_cst) const volatile noexcept;
    102     T load(memory_order m = memory_order_seq_cst) const noexcept;
    103     operator T() const volatile noexcept;
    104     operator T() const noexcept;
    105     T exchange(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
    106     T exchange(T desr, memory_order m = memory_order_seq_cst) noexcept;
    107     bool compare_exchange_weak(T& expc, T desr,
    108                                memory_order s, memory_order f) volatile noexcept;
    109     bool compare_exchange_weak(T& expc, T desr, memory_order s, memory_order f) noexcept;
    110     bool compare_exchange_strong(T& expc, T desr,
    111                                  memory_order s, memory_order f) volatile noexcept;
    112     bool compare_exchange_strong(T& expc, T desr,
    113                                  memory_order s, memory_order f) noexcept;
    114     bool compare_exchange_weak(T& expc, T desr,
    115                                memory_order m = memory_order_seq_cst) volatile noexcept;
    116     bool compare_exchange_weak(T& expc, T desr,
    117                                memory_order m = memory_order_seq_cst) noexcept;
    118     bool compare_exchange_strong(T& expc, T desr,
    119                                 memory_order m = memory_order_seq_cst) volatile noexcept;
    120     bool compare_exchange_strong(T& expc, T desr,
    121                                  memory_order m = memory_order_seq_cst) noexcept;
    122 
    123     atomic() noexcept = default;
    124     constexpr atomic(T desr) noexcept;
    125     atomic(const atomic&) = delete;
    126     atomic& operator=(const atomic&) = delete;
    127     atomic& operator=(const atomic&) volatile = delete;
    128     T operator=(T) volatile noexcept;
    129     T operator=(T) noexcept;
    130 };
    131 
    132 template <>
    133 struct atomic<integral>
    134 {
    135     static constexpr bool is_always_lock_free;
    136     bool is_lock_free() const volatile noexcept;
    137     bool is_lock_free() const noexcept;
    138     void store(integral desr, memory_order m = memory_order_seq_cst) volatile noexcept;
    139     void store(integral desr, memory_order m = memory_order_seq_cst) noexcept;
    140     integral load(memory_order m = memory_order_seq_cst) const volatile noexcept;
    141     integral load(memory_order m = memory_order_seq_cst) const noexcept;
    142     operator integral() const volatile noexcept;
    143     operator integral() const noexcept;
    144     integral exchange(integral desr,
    145                       memory_order m = memory_order_seq_cst) volatile noexcept;
    146     integral exchange(integral desr, memory_order m = memory_order_seq_cst) noexcept;
    147     bool compare_exchange_weak(integral& expc, integral desr,
    148                                memory_order s, memory_order f) volatile noexcept;
    149     bool compare_exchange_weak(integral& expc, integral desr,
    150                                memory_order s, memory_order f) noexcept;
    151     bool compare_exchange_strong(integral& expc, integral desr,
    152                                  memory_order s, memory_order f) volatile noexcept;
    153     bool compare_exchange_strong(integral& expc, integral desr,
    154                                  memory_order s, memory_order f) noexcept;
    155     bool compare_exchange_weak(integral& expc, integral desr,
    156                                memory_order m = memory_order_seq_cst) volatile noexcept;
    157     bool compare_exchange_weak(integral& expc, integral desr,
    158                                memory_order m = memory_order_seq_cst) noexcept;
    159     bool compare_exchange_strong(integral& expc, integral desr,
    160                                 memory_order m = memory_order_seq_cst) volatile noexcept;
    161     bool compare_exchange_strong(integral& expc, integral desr,
    162                                  memory_order m = memory_order_seq_cst) noexcept;
    163 
    164     integral
    165         fetch_add(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
    166     integral fetch_add(integral op, memory_order m = memory_order_seq_cst) noexcept;
    167     integral
    168         fetch_sub(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
    169     integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) noexcept;
    170     integral
    171         fetch_and(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
    172     integral fetch_and(integral op, memory_order m = memory_order_seq_cst) noexcept;
    173     integral
    174         fetch_or(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
    175     integral fetch_or(integral op, memory_order m = memory_order_seq_cst) noexcept;
    176     integral
    177         fetch_xor(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
    178     integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) noexcept;
    179 
    180     atomic() noexcept = default;
    181     constexpr atomic(integral desr) noexcept;
    182     atomic(const atomic&) = delete;
    183     atomic& operator=(const atomic&) = delete;
    184     atomic& operator=(const atomic&) volatile = delete;
    185     integral operator=(integral desr) volatile noexcept;
    186     integral operator=(integral desr) noexcept;
    187 
    188     integral operator++(int) volatile noexcept;
    189     integral operator++(int) noexcept;
    190     integral operator--(int) volatile noexcept;
    191     integral operator--(int) noexcept;
    192     integral operator++() volatile noexcept;
    193     integral operator++() noexcept;
    194     integral operator--() volatile noexcept;
    195     integral operator--() noexcept;
    196     integral operator+=(integral op) volatile noexcept;
    197     integral operator+=(integral op) noexcept;
    198     integral operator-=(integral op) volatile noexcept;
    199     integral operator-=(integral op) noexcept;
    200     integral operator&=(integral op) volatile noexcept;
    201     integral operator&=(integral op) noexcept;
    202     integral operator|=(integral op) volatile noexcept;
    203     integral operator|=(integral op) noexcept;
    204     integral operator^=(integral op) volatile noexcept;
    205     integral operator^=(integral op) noexcept;
    206 };
    207 
    208 template <class T>
    209 struct atomic<T*>
    210 {
    211     static constexpr bool is_always_lock_free;
    212     bool is_lock_free() const volatile noexcept;
    213     bool is_lock_free() const noexcept;
    214     void store(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
    215     void store(T* desr, memory_order m = memory_order_seq_cst) noexcept;
    216     T* load(memory_order m = memory_order_seq_cst) const volatile noexcept;
    217     T* load(memory_order m = memory_order_seq_cst) const noexcept;
    218     operator T*() const volatile noexcept;
    219     operator T*() const noexcept;
    220     T* exchange(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
    221     T* exchange(T* desr, memory_order m = memory_order_seq_cst) noexcept;
    222     bool compare_exchange_weak(T*& expc, T* desr,
    223                                memory_order s, memory_order f) volatile noexcept;
    224     bool compare_exchange_weak(T*& expc, T* desr,
    225                                memory_order s, memory_order f) noexcept;
    226     bool compare_exchange_strong(T*& expc, T* desr,
    227                                  memory_order s, memory_order f) volatile noexcept;
    228     bool compare_exchange_strong(T*& expc, T* desr,
    229                                  memory_order s, memory_order f) noexcept;
    230     bool compare_exchange_weak(T*& expc, T* desr,
    231                                memory_order m = memory_order_seq_cst) volatile noexcept;
    232     bool compare_exchange_weak(T*& expc, T* desr,
    233                                memory_order m = memory_order_seq_cst) noexcept;
    234     bool compare_exchange_strong(T*& expc, T* desr,
    235                                 memory_order m = memory_order_seq_cst) volatile noexcept;
    236     bool compare_exchange_strong(T*& expc, T* desr,
    237                                  memory_order m = memory_order_seq_cst) noexcept;
    238     T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
    239     T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
    240     T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
    241     T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
    242 
    243     atomic() noexcept = default;
    244     constexpr atomic(T* desr) noexcept;
    245     atomic(const atomic&) = delete;
    246     atomic& operator=(const atomic&) = delete;
    247     atomic& operator=(const atomic&) volatile = delete;
    248 
    249     T* operator=(T*) volatile noexcept;
    250     T* operator=(T*) noexcept;
    251     T* operator++(int) volatile noexcept;
    252     T* operator++(int) noexcept;
    253     T* operator--(int) volatile noexcept;
    254     T* operator--(int) noexcept;
    255     T* operator++() volatile noexcept;
    256     T* operator++() noexcept;
    257     T* operator--() volatile noexcept;
    258     T* operator--() noexcept;
    259     T* operator+=(ptrdiff_t op) volatile noexcept;
    260     T* operator+=(ptrdiff_t op) noexcept;
    261     T* operator-=(ptrdiff_t op) volatile noexcept;
    262     T* operator-=(ptrdiff_t op) noexcept;
    263 };
    264 
    265 
    266 template <class T>
    267     bool
    268     atomic_is_lock_free(const volatile atomic<T>* obj) noexcept;
    269 
    270 template <class T>
    271     bool
    272     atomic_is_lock_free(const atomic<T>* obj) noexcept;
    273 
    274 template <class T>
    275     void
    276     atomic_init(volatile atomic<T>* obj, T desr) noexcept;
    277 
    278 template <class T>
    279     void
    280     atomic_init(atomic<T>* obj, T desr) noexcept;
    281 
    282 template <class T>
    283     void
    284     atomic_store(volatile atomic<T>* obj, T desr) noexcept;
    285 
    286 template <class T>
    287     void
    288     atomic_store(atomic<T>* obj, T desr) noexcept;
    289 
    290 template <class T>
    291     void
    292     atomic_store_explicit(volatile atomic<T>* obj, T desr, memory_order m) noexcept;
    293 
    294 template <class T>
    295     void
    296     atomic_store_explicit(atomic<T>* obj, T desr, memory_order m) noexcept;
    297 
    298 template <class T>
    299     T
    300     atomic_load(const volatile atomic<T>* obj) noexcept;
    301 
    302 template <class T>
    303     T
    304     atomic_load(const atomic<T>* obj) noexcept;
    305 
    306 template <class T>
    307     T
    308     atomic_load_explicit(const volatile atomic<T>* obj, memory_order m) noexcept;
    309 
    310 template <class T>
    311     T
    312     atomic_load_explicit(const atomic<T>* obj, memory_order m) noexcept;
    313 
    314 template <class T>
    315     T
    316     atomic_exchange(volatile atomic<T>* obj, T desr) noexcept;
    317 
    318 template <class T>
    319     T
    320     atomic_exchange(atomic<T>* obj, T desr) noexcept;
    321 
    322 template <class T>
    323     T
    324     atomic_exchange_explicit(volatile atomic<T>* obj, T desr, memory_order m) noexcept;
    325 
    326 template <class T>
    327     T
    328     atomic_exchange_explicit(atomic<T>* obj, T desr, memory_order m) noexcept;
    329 
    330 template <class T>
    331     bool
    332     atomic_compare_exchange_weak(volatile atomic<T>* obj, T* expc, T desr) noexcept;
    333 
    334 template <class T>
    335     bool
    336     atomic_compare_exchange_weak(atomic<T>* obj, T* expc, T desr) noexcept;
    337 
    338 template <class T>
    339     bool
    340     atomic_compare_exchange_strong(volatile atomic<T>* obj, T* expc, T desr) noexcept;
    341 
    342 template <class T>
    343     bool
    344     atomic_compare_exchange_strong(atomic<T>* obj, T* expc, T desr) noexcept;
    345 
    346 template <class T>
    347     bool
    348     atomic_compare_exchange_weak_explicit(volatile atomic<T>* obj, T* expc,
    349                                           T desr,
    350                                           memory_order s, memory_order f) noexcept;
    351 
    352 template <class T>
    353     bool
    354     atomic_compare_exchange_weak_explicit(atomic<T>* obj, T* expc, T desr,
    355                                           memory_order s, memory_order f) noexcept;
    356 
    357 template <class T>
    358     bool
    359     atomic_compare_exchange_strong_explicit(volatile atomic<T>* obj,
    360                                             T* expc, T desr,
    361                                             memory_order s, memory_order f) noexcept;
    362 
    363 template <class T>
    364     bool
    365     atomic_compare_exchange_strong_explicit(atomic<T>* obj, T* expc,
    366                                             T desr,
    367                                             memory_order s, memory_order f) noexcept;
    368 
    369 template <class Integral>
    370     Integral
    371     atomic_fetch_add(volatile atomic<Integral>* obj, Integral op) noexcept;
    372 
    373 template <class Integral>
    374     Integral
    375     atomic_fetch_add(atomic<Integral>* obj, Integral op) noexcept;
    376 
    377 template <class Integral>
    378     Integral
    379     atomic_fetch_add_explicit(volatile atomic<Integral>* obj, Integral op,
    380                               memory_order m) noexcept;
    381 template <class Integral>
    382     Integral
    383     atomic_fetch_add_explicit(atomic<Integral>* obj, Integral op,
    384                               memory_order m) noexcept;
    385 template <class Integral>
    386     Integral
    387     atomic_fetch_sub(volatile atomic<Integral>* obj, Integral op) noexcept;
    388 
    389 template <class Integral>
    390     Integral
    391     atomic_fetch_sub(atomic<Integral>* obj, Integral op) noexcept;
    392 
    393 template <class Integral>
    394     Integral
    395     atomic_fetch_sub_explicit(volatile atomic<Integral>* obj, Integral op,
    396                               memory_order m) noexcept;
    397 template <class Integral>
    398     Integral
    399     atomic_fetch_sub_explicit(atomic<Integral>* obj, Integral op,
    400                               memory_order m) noexcept;
    401 template <class Integral>
    402     Integral
    403     atomic_fetch_and(volatile atomic<Integral>* obj, Integral op) noexcept;
    404 
    405 template <class Integral>
    406     Integral
    407     atomic_fetch_and(atomic<Integral>* obj, Integral op) noexcept;
    408 
    409 template <class Integral>
    410     Integral
    411     atomic_fetch_and_explicit(volatile atomic<Integral>* obj, Integral op,
    412                               memory_order m) noexcept;
    413 template <class Integral>
    414     Integral
    415     atomic_fetch_and_explicit(atomic<Integral>* obj, Integral op,
    416                               memory_order m) noexcept;
    417 template <class Integral>
    418     Integral
    419     atomic_fetch_or(volatile atomic<Integral>* obj, Integral op) noexcept;
    420 
    421 template <class Integral>
    422     Integral
    423     atomic_fetch_or(atomic<Integral>* obj, Integral op) noexcept;
    424 
    425 template <class Integral>
    426     Integral
    427     atomic_fetch_or_explicit(volatile atomic<Integral>* obj, Integral op,
    428                              memory_order m) noexcept;
    429 template <class Integral>
    430     Integral
    431     atomic_fetch_or_explicit(atomic<Integral>* obj, Integral op,
    432                              memory_order m) noexcept;
    433 template <class Integral>
    434     Integral
    435     atomic_fetch_xor(volatile atomic<Integral>* obj, Integral op) noexcept;
    436 
    437 template <class Integral>
    438     Integral
    439     atomic_fetch_xor(atomic<Integral>* obj, Integral op) noexcept;
    440 
    441 template <class Integral>
    442     Integral
    443     atomic_fetch_xor_explicit(volatile atomic<Integral>* obj, Integral op,
    444                               memory_order m) noexcept;
    445 template <class Integral>
    446     Integral
    447     atomic_fetch_xor_explicit(atomic<Integral>* obj, Integral op,
    448                               memory_order m) noexcept;
    449 
    450 template <class T>
    451     T*
    452     atomic_fetch_add(volatile atomic<T*>* obj, ptrdiff_t op) noexcept;
    453 
    454 template <class T>
    455     T*
    456     atomic_fetch_add(atomic<T*>* obj, ptrdiff_t op) noexcept;
    457 
    458 template <class T>
    459     T*
    460     atomic_fetch_add_explicit(volatile atomic<T*>* obj, ptrdiff_t op,
    461                               memory_order m) noexcept;
    462 template <class T>
    463     T*
    464     atomic_fetch_add_explicit(atomic<T*>* obj, ptrdiff_t op, memory_order m) noexcept;
    465 
    466 template <class T>
    467     T*
    468     atomic_fetch_sub(volatile atomic<T*>* obj, ptrdiff_t op) noexcept;
    469 
    470 template <class T>
    471     T*
    472     atomic_fetch_sub(atomic<T*>* obj, ptrdiff_t op) noexcept;
    473 
    474 template <class T>
    475     T*
    476     atomic_fetch_sub_explicit(volatile atomic<T*>* obj, ptrdiff_t op,
    477                               memory_order m) noexcept;
    478 template <class T>
    479     T*
    480     atomic_fetch_sub_explicit(atomic<T*>* obj, ptrdiff_t op, memory_order m) noexcept;
    481 
    482 // Atomics for standard typedef types
    483 
    484 typedef atomic<bool>               atomic_bool;
    485 typedef atomic<char>               atomic_char;
    486 typedef atomic<signed char>        atomic_schar;
    487 typedef atomic<unsigned char>      atomic_uchar;
    488 typedef atomic<short>              atomic_short;
    489 typedef atomic<unsigned short>     atomic_ushort;
    490 typedef atomic<int>                atomic_int;
    491 typedef atomic<unsigned int>       atomic_uint;
    492 typedef atomic<long>               atomic_long;
    493 typedef atomic<unsigned long>      atomic_ulong;
    494 typedef atomic<long long>          atomic_llong;
    495 typedef atomic<unsigned long long> atomic_ullong;
    496 typedef atomic<char16_t>           atomic_char16_t;
    497 typedef atomic<char32_t>           atomic_char32_t;
    498 typedef atomic<wchar_t>            atomic_wchar_t;
    499 
    500 typedef atomic<int_least8_t>   atomic_int_least8_t;
    501 typedef atomic<uint_least8_t>  atomic_uint_least8_t;
    502 typedef atomic<int_least16_t>  atomic_int_least16_t;
    503 typedef atomic<uint_least16_t> atomic_uint_least16_t;
    504 typedef atomic<int_least32_t>  atomic_int_least32_t;
    505 typedef atomic<uint_least32_t> atomic_uint_least32_t;
    506 typedef atomic<int_least64_t>  atomic_int_least64_t;
    507 typedef atomic<uint_least64_t> atomic_uint_least64_t;
    508 
    509 typedef atomic<int_fast8_t>   atomic_int_fast8_t;
    510 typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
    511 typedef atomic<int_fast16_t>  atomic_int_fast16_t;
    512 typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
    513 typedef atomic<int_fast32_t>  atomic_int_fast32_t;
    514 typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
    515 typedef atomic<int_fast64_t>  atomic_int_fast64_t;
    516 typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
    517 
    518 typedef atomic<int8_t>   atomic_int8_t;
    519 typedef atomic<uint8_t>  atomic_uint8_t;
    520 typedef atomic<int16_t>  atomic_int16_t;
    521 typedef atomic<uint16_t> atomic_uint16_t;
    522 typedef atomic<int32_t>  atomic_int32_t;
    523 typedef atomic<uint32_t> atomic_uint32_t;
    524 typedef atomic<int64_t>  atomic_int64_t;
    525 typedef atomic<uint64_t> atomic_uint64_t;
    526 
    527 typedef atomic<intptr_t>  atomic_intptr_t;
    528 typedef atomic<uintptr_t> atomic_uintptr_t;
    529 typedef atomic<size_t>    atomic_size_t;
    530 typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
    531 typedef atomic<intmax_t>  atomic_intmax_t;
    532 typedef atomic<uintmax_t> atomic_uintmax_t;
    533 
    534 // fences
    535 
    536 void atomic_thread_fence(memory_order m) noexcept;
    537 void atomic_signal_fence(memory_order m) noexcept;
    538 
    539 }  // std
    540 
    541 */
    542 
    543 #include <__config>
    544 #include <cstddef>
    545 #include <cstdint>
    546 #include <type_traits>
    547 
    548 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
    549 #pragma GCC system_header
    550 #endif
    551 
    552 #ifdef _LIBCPP_HAS_NO_THREADS
    553 #error <atomic> is not supported on this single threaded system
    554 #endif
    555 #if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
    556 #error <atomic> is not implemented
    557 #endif
    558 
    559 #if _LIBCPP_STD_VER > 14
    560 # define __cpp_lib_atomic_is_always_lock_free 201603L
    561 #endif
    562 
    563 #define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \
    564   _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \
    565                            __m == memory_order_acquire || \
    566                            __m == memory_order_acq_rel,   \
    567                         "memory order argument to atomic operation is invalid")
    568 
    569 #define _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) \
    570   _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_release || \
    571                            __m == memory_order_acq_rel,   \
    572                         "memory order argument to atomic operation is invalid")
    573 
    574 #define _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__m, __f) \
    575   _LIBCPP_DIAGNOSE_WARNING(__f == memory_order_release || \
    576                            __f == memory_order_acq_rel,   \
    577                         "memory order argument to atomic operation is invalid")
    578 
    579 _LIBCPP_BEGIN_NAMESPACE_STD
    580 
    581 typedef enum memory_order
    582 {
    583     memory_order_relaxed, memory_order_consume, memory_order_acquire,
    584     memory_order_release, memory_order_acq_rel, memory_order_seq_cst
    585 } memory_order;
    586 
    587 #if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
    588 namespace __gcc_atomic {
    589 template <typename _Tp>
    590 struct __gcc_atomic_t {
    591 
    592 #if _GNUC_VER >= 501
    593     static_assert(is_trivially_copyable<_Tp>::value,
    594       "std::atomic<Tp> requires that 'Tp' be a trivially copyable type");
    595 #endif
    596 
    597   _LIBCPP_INLINE_VISIBILITY
    598 #ifndef _LIBCPP_CXX03_LANG
    599     __gcc_atomic_t() _NOEXCEPT = default;
    600 #else
    601     __gcc_atomic_t() _NOEXCEPT : __a_value() {}
    602 #endif // _LIBCPP_CXX03_LANG
    603   _LIBCPP_CONSTEXPR explicit __gcc_atomic_t(_Tp value) _NOEXCEPT
    604     : __a_value(value) {}
    605   _Tp __a_value;
    606 };
    607 #define _Atomic(x) __gcc_atomic::__gcc_atomic_t<x>
    608 
    609 template <typename _Tp> _Tp __create();
    610 
    611 template <typename _Tp, typename _Td>
    612 typename enable_if<sizeof(_Tp()->__a_value = __create<_Td>()), char>::type
    613     __test_atomic_assignable(int);
    614 template <typename _Tp, typename _Up>
    615 __two __test_atomic_assignable(...);
    616 
    617 template <typename _Tp, typename _Td>
    618 struct __can_assign {
    619   static const bool value =
    620       sizeof(__test_atomic_assignable<_Tp, _Td>(1)) == sizeof(char);
    621 };
    622 
    623 static inline _LIBCPP_CONSTEXPR int __to_gcc_order(memory_order __order) {
    624   // Avoid switch statement to make this a constexpr.
    625   return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
    626          (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
    627           (__order == memory_order_release ? __ATOMIC_RELEASE:
    628            (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
    629             (__order == memory_order_acq_rel ? __ATOMIC_ACQ_REL:
    630               __ATOMIC_CONSUME))));
    631 }
    632 
    633 static inline _LIBCPP_CONSTEXPR int __to_gcc_failure_order(memory_order __order) {
    634   // Avoid switch statement to make this a constexpr.
    635   return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
    636          (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
    637           (__order == memory_order_release ? __ATOMIC_RELAXED:
    638            (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
    639             (__order == memory_order_acq_rel ? __ATOMIC_ACQUIRE:
    640               __ATOMIC_CONSUME))));
    641 }
    642 
    643 } // namespace __gcc_atomic
    644 
    645 template <typename _Tp>
    646 static inline
    647 typename enable_if<
    648     __gcc_atomic::__can_assign<volatile _Atomic(_Tp)*, _Tp>::value>::type
    649 __c11_atomic_init(volatile _Atomic(_Tp)* __a,  _Tp __val) {
    650   __a->__a_value = __val;
    651 }
    652 
    653 template <typename _Tp>
    654 static inline
    655 typename enable_if<
    656     !__gcc_atomic::__can_assign<volatile _Atomic(_Tp)*, _Tp>::value &&
    657      __gcc_atomic::__can_assign<         _Atomic(_Tp)*, _Tp>::value>::type
    658 __c11_atomic_init(volatile _Atomic(_Tp)* __a,  _Tp __val) {
    659   // [atomics.types.generic]p1 guarantees _Tp is trivially copyable. Because
    660   // the default operator= in an object is not volatile, a byte-by-byte copy
    661   // is required.
    662   volatile char* to = reinterpret_cast<volatile char*>(&__a->__a_value);
    663   volatile char* end = to + sizeof(_Tp);
    664   char* from = reinterpret_cast<char*>(&__val);
    665   while (to != end) {
    666     *to++ = *from++;
    667   }
    668 }
    669 
    670 template <typename _Tp>
    671 static inline void __c11_atomic_init(_Atomic(_Tp)* __a,  _Tp __val) {
    672   __a->__a_value = __val;
    673 }
    674 
    675 static inline void __c11_atomic_thread_fence(memory_order __order) {
    676   __atomic_thread_fence(__gcc_atomic::__to_gcc_order(__order));
    677 }
    678 
    679 static inline void __c11_atomic_signal_fence(memory_order __order) {
    680   __atomic_signal_fence(__gcc_atomic::__to_gcc_order(__order));
    681 }
    682 
    683 template <typename _Tp>
    684 static inline void __c11_atomic_store(volatile _Atomic(_Tp)* __a,  _Tp __val,
    685                                       memory_order __order) {
    686   return __atomic_store(&__a->__a_value, &__val,
    687                         __gcc_atomic::__to_gcc_order(__order));
    688 }
    689 
    690 template <typename _Tp>
    691 static inline void __c11_atomic_store(_Atomic(_Tp)* __a,  _Tp __val,
    692                                       memory_order __order) {
    693   __atomic_store(&__a->__a_value, &__val,
    694                  __gcc_atomic::__to_gcc_order(__order));
    695 }
    696 
    697 template <typename _Tp>
    698 static inline _Tp __c11_atomic_load(volatile _Atomic(_Tp)* __a,
    699                                     memory_order __order) {
    700   _Tp __ret;
    701   __atomic_load(&__a->__a_value, &__ret,
    702                 __gcc_atomic::__to_gcc_order(__order));
    703   return __ret;
    704 }
    705 
    706 template <typename _Tp>
    707 static inline _Tp __c11_atomic_load(_Atomic(_Tp)* __a, memory_order __order) {
    708   _Tp __ret;
    709   __atomic_load(&__a->__a_value, &__ret,
    710                 __gcc_atomic::__to_gcc_order(__order));
    711   return __ret;
    712 }
    713 
    714 template <typename _Tp>
    715 static inline _Tp __c11_atomic_exchange(volatile _Atomic(_Tp)* __a,
    716                                         _Tp __value, memory_order __order) {
    717   _Tp __ret;
    718   __atomic_exchange(&__a->__a_value, &__value, &__ret,
    719                     __gcc_atomic::__to_gcc_order(__order));
    720   return __ret;
    721 }
    722 
    723 template <typename _Tp>
    724 static inline _Tp __c11_atomic_exchange(_Atomic(_Tp)* __a, _Tp __value,
    725                                         memory_order __order) {
    726   _Tp __ret;
    727   __atomic_exchange(&__a->__a_value, &__value, &__ret,
    728                     __gcc_atomic::__to_gcc_order(__order));
    729   return __ret;
    730 }
    731 
    732 template <typename _Tp>
    733 static inline bool __c11_atomic_compare_exchange_strong(
    734     volatile _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value,
    735     memory_order __success, memory_order __failure) {
    736   return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
    737                                    false,
    738                                    __gcc_atomic::__to_gcc_order(__success),
    739                                    __gcc_atomic::__to_gcc_failure_order(__failure));
    740 }
    741 
    742 template <typename _Tp>
    743 static inline bool __c11_atomic_compare_exchange_strong(
    744     _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value, memory_order __success,
    745     memory_order __failure) {
    746   return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
    747                                    false,
    748                                    __gcc_atomic::__to_gcc_order(__success),
    749                                    __gcc_atomic::__to_gcc_failure_order(__failure));
    750 }
    751 
    752 template <typename _Tp>
    753 static inline bool __c11_atomic_compare_exchange_weak(
    754     volatile _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value,
    755     memory_order __success, memory_order __failure) {
    756   return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
    757                                    true,
    758                                    __gcc_atomic::__to_gcc_order(__success),
    759                                    __gcc_atomic::__to_gcc_failure_order(__failure));
    760 }
    761 
    762 template <typename _Tp>
    763 static inline bool __c11_atomic_compare_exchange_weak(
    764     _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value, memory_order __success,
    765     memory_order __failure) {
    766   return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
    767                                    true,
    768                                    __gcc_atomic::__to_gcc_order(__success),
    769                                    __gcc_atomic::__to_gcc_failure_order(__failure));
    770 }
    771 
    772 template <typename _Tp>
    773 struct __skip_amt { enum {value = 1}; };
    774 
    775 template <typename _Tp>
    776 struct __skip_amt<_Tp*> { enum {value = sizeof(_Tp)}; };
    777 
    778 // FIXME: Haven't figured out what the spec says about using arrays with
    779 // atomic_fetch_add. Force a failure rather than creating bad behavior.
    780 template <typename _Tp>
    781 struct __skip_amt<_Tp[]> { };
    782 template <typename _Tp, int n>
    783 struct __skip_amt<_Tp[n]> { };
    784 
    785 template <typename _Tp, typename _Td>
    786 static inline _Tp __c11_atomic_fetch_add(volatile _Atomic(_Tp)* __a,
    787                                          _Td __delta, memory_order __order) {
    788   return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
    789                             __gcc_atomic::__to_gcc_order(__order));
    790 }
    791 
    792 template <typename _Tp, typename _Td>
    793 static inline _Tp __c11_atomic_fetch_add(_Atomic(_Tp)* __a, _Td __delta,
    794                                          memory_order __order) {
    795   return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
    796                             __gcc_atomic::__to_gcc_order(__order));
    797 }
    798 
    799 template <typename _Tp, typename _Td>
    800 static inline _Tp __c11_atomic_fetch_sub(volatile _Atomic(_Tp)* __a,
    801                                          _Td __delta, memory_order __order) {
    802   return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
    803                             __gcc_atomic::__to_gcc_order(__order));
    804 }
    805 
    806 template <typename _Tp, typename _Td>
    807 static inline _Tp __c11_atomic_fetch_sub(_Atomic(_Tp)* __a, _Td __delta,
    808                                          memory_order __order) {
    809   return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
    810                             __gcc_atomic::__to_gcc_order(__order));
    811 }
    812 
    813 template <typename _Tp>
    814 static inline _Tp __c11_atomic_fetch_and(volatile _Atomic(_Tp)* __a,
    815                                          _Tp __pattern, memory_order __order) {
    816   return __atomic_fetch_and(&__a->__a_value, __pattern,
    817                             __gcc_atomic::__to_gcc_order(__order));
    818 }
    819 
    820 template <typename _Tp>
    821 static inline _Tp __c11_atomic_fetch_and(_Atomic(_Tp)* __a,
    822                                          _Tp __pattern, memory_order __order) {
    823   return __atomic_fetch_and(&__a->__a_value, __pattern,
    824                             __gcc_atomic::__to_gcc_order(__order));
    825 }
    826 
    827 template <typename _Tp>
    828 static inline _Tp __c11_atomic_fetch_or(volatile _Atomic(_Tp)* __a,
    829                                         _Tp __pattern, memory_order __order) {
    830   return __atomic_fetch_or(&__a->__a_value, __pattern,
    831                            __gcc_atomic::__to_gcc_order(__order));
    832 }
    833 
    834 template <typename _Tp>
    835 static inline _Tp __c11_atomic_fetch_or(_Atomic(_Tp)* __a, _Tp __pattern,
    836                                         memory_order __order) {
    837   return __atomic_fetch_or(&__a->__a_value, __pattern,
    838                            __gcc_atomic::__to_gcc_order(__order));
    839 }
    840 
    841 template <typename _Tp>
    842 static inline _Tp __c11_atomic_fetch_xor(volatile _Atomic(_Tp)* __a,
    843                                          _Tp __pattern, memory_order __order) {
    844   return __atomic_fetch_xor(&__a->__a_value, __pattern,
    845                             __gcc_atomic::__to_gcc_order(__order));
    846 }
    847 
    848 template <typename _Tp>
    849 static inline _Tp __c11_atomic_fetch_xor(_Atomic(_Tp)* __a, _Tp __pattern,
    850                                          memory_order __order) {
    851   return __atomic_fetch_xor(&__a->__a_value, __pattern,
    852                             __gcc_atomic::__to_gcc_order(__order));
    853 }
    854 #endif // _LIBCPP_HAS_GCC_ATOMIC_IMP
    855 
    856 template <class _Tp>
    857 inline _LIBCPP_INLINE_VISIBILITY
    858 _Tp
    859 kill_dependency(_Tp __y) _NOEXCEPT
    860 {
    861     return __y;
    862 }
    863 
    864 #if defined(__CLANG_ATOMIC_BOOL_LOCK_FREE)
    865 # define ATOMIC_BOOL_LOCK_FREE      __CLANG_ATOMIC_BOOL_LOCK_FREE
    866 # define ATOMIC_CHAR_LOCK_FREE      __CLANG_ATOMIC_CHAR_LOCK_FREE
    867 # define ATOMIC_CHAR16_T_LOCK_FREE  __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
    868 # define ATOMIC_CHAR32_T_LOCK_FREE  __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
    869 # define ATOMIC_WCHAR_T_LOCK_FREE   __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
    870 # define ATOMIC_SHORT_LOCK_FREE     __CLANG_ATOMIC_SHORT_LOCK_FREE
    871 # define ATOMIC_INT_LOCK_FREE       __CLANG_ATOMIC_INT_LOCK_FREE
    872 # define ATOMIC_LONG_LOCK_FREE      __CLANG_ATOMIC_LONG_LOCK_FREE
    873 # define ATOMIC_LLONG_LOCK_FREE     __CLANG_ATOMIC_LLONG_LOCK_FREE
    874 # define ATOMIC_POINTER_LOCK_FREE   __CLANG_ATOMIC_POINTER_LOCK_FREE
    875 #else
    876 # define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE
    877 # define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE
    878 # define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE
    879 # define ATOMIC_CHAR32_T_LOCK_FREE  __GCC_ATOMIC_CHAR32_T_LOCK_FREE
    880 # define ATOMIC_WCHAR_T_LOCK_FREE   __GCC_ATOMIC_WCHAR_T_LOCK_FREE
    881 # define ATOMIC_SHORT_LOCK_FREE     __GCC_ATOMIC_SHORT_LOCK_FREE
    882 # define ATOMIC_INT_LOCK_FREE       __GCC_ATOMIC_INT_LOCK_FREE
    883 # define ATOMIC_LONG_LOCK_FREE      __GCC_ATOMIC_LONG_LOCK_FREE
    884 # define ATOMIC_LLONG_LOCK_FREE     __GCC_ATOMIC_LLONG_LOCK_FREE
    885 # define ATOMIC_POINTER_LOCK_FREE   __GCC_ATOMIC_POINTER_LOCK_FREE
    886 #endif
    887 
    888 // general atomic<T>
    889 
    890 template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value>
    891 struct __atomic_base  // false
    892 {
    893     mutable _Atomic(_Tp) __a_;
    894 
    895 #if defined(__cpp_lib_atomic_is_always_lock_free)
    896   static _LIBCPP_CONSTEXPR bool is_always_lock_free = __atomic_always_lock_free(sizeof(__a_), 0);
    897 #endif
    898 
    899     _LIBCPP_INLINE_VISIBILITY
    900     bool is_lock_free() const volatile _NOEXCEPT
    901     {
    902 #if defined(_LIBCPP_HAS_C_ATOMIC_IMP)
    903     return __c11_atomic_is_lock_free(sizeof(_Tp));
    904 #else
    905     return __atomic_is_lock_free(sizeof(_Tp), 0);
    906 #endif
    907     }
    908     _LIBCPP_INLINE_VISIBILITY
    909     bool is_lock_free() const _NOEXCEPT
    910         {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();}
    911     _LIBCPP_INLINE_VISIBILITY
    912     void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
    913       _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
    914         {__c11_atomic_store(&__a_, __d, __m);}
    915     _LIBCPP_INLINE_VISIBILITY
    916     void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
    917       _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
    918         {__c11_atomic_store(&__a_, __d, __m);}
    919     _LIBCPP_INLINE_VISIBILITY
    920     _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
    921       _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
    922         {return __c11_atomic_load(&__a_, __m);}
    923     _LIBCPP_INLINE_VISIBILITY
    924     _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
    925       _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
    926         {return __c11_atomic_load(&__a_, __m);}
    927     _LIBCPP_INLINE_VISIBILITY
    928     operator _Tp() const volatile _NOEXCEPT {return load();}
    929     _LIBCPP_INLINE_VISIBILITY
    930     operator _Tp() const _NOEXCEPT          {return load();}
    931     _LIBCPP_INLINE_VISIBILITY
    932     _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
    933         {return __c11_atomic_exchange(&__a_, __d, __m);}
    934     _LIBCPP_INLINE_VISIBILITY
    935     _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
    936         {return __c11_atomic_exchange(&__a_, __d, __m);}
    937     _LIBCPP_INLINE_VISIBILITY
    938     bool compare_exchange_weak(_Tp& __e, _Tp __d,
    939                                memory_order __s, memory_order __f) volatile _NOEXCEPT
    940       _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
    941         {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
    942     _LIBCPP_INLINE_VISIBILITY
    943     bool compare_exchange_weak(_Tp& __e, _Tp __d,
    944                                memory_order __s, memory_order __f) _NOEXCEPT
    945       _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
    946         {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
    947     _LIBCPP_INLINE_VISIBILITY
    948     bool compare_exchange_strong(_Tp& __e, _Tp __d,
    949                                  memory_order __s, memory_order __f) volatile _NOEXCEPT
    950       _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
    951         {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
    952     _LIBCPP_INLINE_VISIBILITY
    953     bool compare_exchange_strong(_Tp& __e, _Tp __d,
    954                                  memory_order __s, memory_order __f) _NOEXCEPT
    955       _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
    956         {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
    957     _LIBCPP_INLINE_VISIBILITY
    958     bool compare_exchange_weak(_Tp& __e, _Tp __d,
    959                               memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
    960         {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
    961     _LIBCPP_INLINE_VISIBILITY
    962     bool compare_exchange_weak(_Tp& __e, _Tp __d,
    963                                memory_order __m = memory_order_seq_cst) _NOEXCEPT
    964         {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
    965     _LIBCPP_INLINE_VISIBILITY
    966     bool compare_exchange_strong(_Tp& __e, _Tp __d,
    967                               memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
    968         {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
    969     _LIBCPP_INLINE_VISIBILITY
    970     bool compare_exchange_strong(_Tp& __e, _Tp __d,
    971                                  memory_order __m = memory_order_seq_cst) _NOEXCEPT
    972         {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
    973 
    974     _LIBCPP_INLINE_VISIBILITY
    975 #ifndef _LIBCPP_CXX03_LANG
    976     __atomic_base() _NOEXCEPT = default;
    977 #else
    978     __atomic_base() _NOEXCEPT : __a_() {}
    979 #endif // _LIBCPP_CXX03_LANG
    980 
    981     _LIBCPP_INLINE_VISIBILITY
    982     _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {}
    983 #ifndef _LIBCPP_CXX03_LANG
    984     __atomic_base(const __atomic_base&) = delete;
    985     __atomic_base& operator=(const __atomic_base&) = delete;
    986     __atomic_base& operator=(const __atomic_base&) volatile = delete;
    987 #else
    988 private:
    989     __atomic_base(const __atomic_base&);
    990     __atomic_base& operator=(const __atomic_base&);
    991     __atomic_base& operator=(const __atomic_base&) volatile;
    992 #endif
    993 };
    994 
    995 #if defined(__cpp_lib_atomic_is_always_lock_free)
    996 template <class _Tp, bool __b>
    997 _LIBCPP_CONSTEXPR bool __atomic_base<_Tp, __b>::is_always_lock_free;
    998 #endif
    999 
   1000 // atomic<Integral>
   1001 
   1002 template <class _Tp>
   1003 struct __atomic_base<_Tp, true>
   1004     : public __atomic_base<_Tp, false>
   1005 {
   1006     typedef __atomic_base<_Tp, false> __base;
   1007     _LIBCPP_INLINE_VISIBILITY
   1008     __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT
   1009     _LIBCPP_INLINE_VISIBILITY
   1010     _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}
   1011 
   1012     _LIBCPP_INLINE_VISIBILITY
   1013     _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1014         {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
   1015     _LIBCPP_INLINE_VISIBILITY
   1016     _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1017         {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
   1018     _LIBCPP_INLINE_VISIBILITY
   1019     _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1020         {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
   1021     _LIBCPP_INLINE_VISIBILITY
   1022     _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1023         {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
   1024     _LIBCPP_INLINE_VISIBILITY
   1025     _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1026         {return __c11_atomic_fetch_and(&this->__a_, __op, __m);}
   1027     _LIBCPP_INLINE_VISIBILITY
   1028     _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1029         {return __c11_atomic_fetch_and(&this->__a_, __op, __m);}
   1030     _LIBCPP_INLINE_VISIBILITY
   1031     _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1032         {return __c11_atomic_fetch_or(&this->__a_, __op, __m);}
   1033     _LIBCPP_INLINE_VISIBILITY
   1034     _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1035         {return __c11_atomic_fetch_or(&this->__a_, __op, __m);}
   1036     _LIBCPP_INLINE_VISIBILITY
   1037     _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1038         {return __c11_atomic_fetch_xor(&this->__a_, __op, __m);}
   1039     _LIBCPP_INLINE_VISIBILITY
   1040     _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1041         {return __c11_atomic_fetch_xor(&this->__a_, __op, __m);}
   1042 
   1043     _LIBCPP_INLINE_VISIBILITY
   1044     _Tp operator++(int) volatile _NOEXCEPT      {return fetch_add(_Tp(1));}
   1045     _LIBCPP_INLINE_VISIBILITY
   1046     _Tp operator++(int) _NOEXCEPT               {return fetch_add(_Tp(1));}
   1047     _LIBCPP_INLINE_VISIBILITY
   1048     _Tp operator--(int) volatile _NOEXCEPT      {return fetch_sub(_Tp(1));}
   1049     _LIBCPP_INLINE_VISIBILITY
   1050     _Tp operator--(int) _NOEXCEPT               {return fetch_sub(_Tp(1));}
   1051     _LIBCPP_INLINE_VISIBILITY
   1052     _Tp operator++() volatile _NOEXCEPT         {return fetch_add(_Tp(1)) + _Tp(1);}
   1053     _LIBCPP_INLINE_VISIBILITY
   1054     _Tp operator++() _NOEXCEPT                  {return fetch_add(_Tp(1)) + _Tp(1);}
   1055     _LIBCPP_INLINE_VISIBILITY
   1056     _Tp operator--() volatile _NOEXCEPT         {return fetch_sub(_Tp(1)) - _Tp(1);}
   1057     _LIBCPP_INLINE_VISIBILITY
   1058     _Tp operator--() _NOEXCEPT                  {return fetch_sub(_Tp(1)) - _Tp(1);}
   1059     _LIBCPP_INLINE_VISIBILITY
   1060     _Tp operator+=(_Tp __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
   1061     _LIBCPP_INLINE_VISIBILITY
   1062     _Tp operator+=(_Tp __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
   1063     _LIBCPP_INLINE_VISIBILITY
   1064     _Tp operator-=(_Tp __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
   1065     _LIBCPP_INLINE_VISIBILITY
   1066     _Tp operator-=(_Tp __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
   1067     _LIBCPP_INLINE_VISIBILITY
   1068     _Tp operator&=(_Tp __op) volatile _NOEXCEPT {return fetch_and(__op) & __op;}
   1069     _LIBCPP_INLINE_VISIBILITY
   1070     _Tp operator&=(_Tp __op) _NOEXCEPT          {return fetch_and(__op) & __op;}
   1071     _LIBCPP_INLINE_VISIBILITY
   1072     _Tp operator|=(_Tp __op) volatile _NOEXCEPT {return fetch_or(__op) | __op;}
   1073     _LIBCPP_INLINE_VISIBILITY
   1074     _Tp operator|=(_Tp __op) _NOEXCEPT          {return fetch_or(__op) | __op;}
   1075     _LIBCPP_INLINE_VISIBILITY
   1076     _Tp operator^=(_Tp __op) volatile _NOEXCEPT {return fetch_xor(__op) ^ __op;}
   1077     _LIBCPP_INLINE_VISIBILITY
   1078     _Tp operator^=(_Tp __op) _NOEXCEPT          {return fetch_xor(__op) ^ __op;}
   1079 };
   1080 
   1081 // atomic<T>
   1082 
   1083 template <class _Tp>
   1084 struct atomic
   1085     : public __atomic_base<_Tp>
   1086 {
   1087     typedef __atomic_base<_Tp> __base;
   1088     _LIBCPP_INLINE_VISIBILITY
   1089     atomic() _NOEXCEPT _LIBCPP_DEFAULT
   1090     _LIBCPP_INLINE_VISIBILITY
   1091     _LIBCPP_CONSTEXPR atomic(_Tp __d) _NOEXCEPT : __base(__d) {}
   1092 
   1093     _LIBCPP_INLINE_VISIBILITY
   1094     _Tp operator=(_Tp __d) volatile _NOEXCEPT
   1095         {__base::store(__d); return __d;}
   1096     _LIBCPP_INLINE_VISIBILITY
   1097     _Tp operator=(_Tp __d) _NOEXCEPT
   1098         {__base::store(__d); return __d;}
   1099 };
   1100 
   1101 // atomic<T*>
   1102 
   1103 template <class _Tp>
   1104 struct atomic<_Tp*>
   1105     : public __atomic_base<_Tp*>
   1106 {
   1107     typedef __atomic_base<_Tp*> __base;
   1108     _LIBCPP_INLINE_VISIBILITY
   1109     atomic() _NOEXCEPT _LIBCPP_DEFAULT
   1110     _LIBCPP_INLINE_VISIBILITY
   1111     _LIBCPP_CONSTEXPR atomic(_Tp* __d) _NOEXCEPT : __base(__d) {}
   1112 
   1113     _LIBCPP_INLINE_VISIBILITY
   1114     _Tp* operator=(_Tp* __d) volatile _NOEXCEPT
   1115         {__base::store(__d); return __d;}
   1116     _LIBCPP_INLINE_VISIBILITY
   1117     _Tp* operator=(_Tp* __d) _NOEXCEPT
   1118         {__base::store(__d); return __d;}
   1119 
   1120     _LIBCPP_INLINE_VISIBILITY
   1121     _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst)
   1122                                                                         volatile _NOEXCEPT
   1123         {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
   1124     _LIBCPP_INLINE_VISIBILITY
   1125     _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1126         {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
   1127     _LIBCPP_INLINE_VISIBILITY
   1128     _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst)
   1129                                                                         volatile _NOEXCEPT
   1130         {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
   1131     _LIBCPP_INLINE_VISIBILITY
   1132     _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1133         {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
   1134 
   1135     _LIBCPP_INLINE_VISIBILITY
   1136     _Tp* operator++(int) volatile _NOEXCEPT            {return fetch_add(1);}
   1137     _LIBCPP_INLINE_VISIBILITY
   1138     _Tp* operator++(int) _NOEXCEPT                     {return fetch_add(1);}
   1139     _LIBCPP_INLINE_VISIBILITY
   1140     _Tp* operator--(int) volatile _NOEXCEPT            {return fetch_sub(1);}
   1141     _LIBCPP_INLINE_VISIBILITY
   1142     _Tp* operator--(int) _NOEXCEPT                     {return fetch_sub(1);}
   1143     _LIBCPP_INLINE_VISIBILITY
   1144     _Tp* operator++() volatile _NOEXCEPT               {return fetch_add(1) + 1;}
   1145     _LIBCPP_INLINE_VISIBILITY
   1146     _Tp* operator++() _NOEXCEPT                        {return fetch_add(1) + 1;}
   1147     _LIBCPP_INLINE_VISIBILITY
   1148     _Tp* operator--() volatile _NOEXCEPT               {return fetch_sub(1) - 1;}
   1149     _LIBCPP_INLINE_VISIBILITY
   1150     _Tp* operator--() _NOEXCEPT                        {return fetch_sub(1) - 1;}
   1151     _LIBCPP_INLINE_VISIBILITY
   1152     _Tp* operator+=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
   1153     _LIBCPP_INLINE_VISIBILITY
   1154     _Tp* operator+=(ptrdiff_t __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
   1155     _LIBCPP_INLINE_VISIBILITY
   1156     _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
   1157     _LIBCPP_INLINE_VISIBILITY
   1158     _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
   1159 };
   1160 
   1161 // atomic_is_lock_free
   1162 
   1163 template <class _Tp>
   1164 inline _LIBCPP_INLINE_VISIBILITY
   1165 bool
   1166 atomic_is_lock_free(const volatile atomic<_Tp>* __o) _NOEXCEPT
   1167 {
   1168     return __o->is_lock_free();
   1169 }
   1170 
   1171 template <class _Tp>
   1172 inline _LIBCPP_INLINE_VISIBILITY
   1173 bool
   1174 atomic_is_lock_free(const atomic<_Tp>* __o) _NOEXCEPT
   1175 {
   1176     return __o->is_lock_free();
   1177 }
   1178 
   1179 // atomic_init
   1180 
   1181 template <class _Tp>
   1182 inline _LIBCPP_INLINE_VISIBILITY
   1183 void
   1184 atomic_init(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
   1185 {
   1186     __c11_atomic_init(&__o->__a_, __d);
   1187 }
   1188 
   1189 template <class _Tp>
   1190 inline _LIBCPP_INLINE_VISIBILITY
   1191 void
   1192 atomic_init(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
   1193 {
   1194     __c11_atomic_init(&__o->__a_, __d);
   1195 }
   1196 
   1197 // atomic_store
   1198 
   1199 template <class _Tp>
   1200 inline _LIBCPP_INLINE_VISIBILITY
   1201 void
   1202 atomic_store(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
   1203 {
   1204     __o->store(__d);
   1205 }
   1206 
   1207 template <class _Tp>
   1208 inline _LIBCPP_INLINE_VISIBILITY
   1209 void
   1210 atomic_store(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
   1211 {
   1212     __o->store(__d);
   1213 }
   1214 
   1215 // atomic_store_explicit
   1216 
   1217 template <class _Tp>
   1218 inline _LIBCPP_INLINE_VISIBILITY
   1219 void
   1220 atomic_store_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
   1221   _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
   1222 {
   1223     __o->store(__d, __m);
   1224 }
   1225 
   1226 template <class _Tp>
   1227 inline _LIBCPP_INLINE_VISIBILITY
   1228 void
   1229 atomic_store_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
   1230   _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
   1231 {
   1232     __o->store(__d, __m);
   1233 }
   1234 
   1235 // atomic_load
   1236 
   1237 template <class _Tp>
   1238 inline _LIBCPP_INLINE_VISIBILITY
   1239 _Tp
   1240 atomic_load(const volatile atomic<_Tp>* __o) _NOEXCEPT
   1241 {
   1242     return __o->load();
   1243 }
   1244 
   1245 template <class _Tp>
   1246 inline _LIBCPP_INLINE_VISIBILITY
   1247 _Tp
   1248 atomic_load(const atomic<_Tp>* __o) _NOEXCEPT
   1249 {
   1250     return __o->load();
   1251 }
   1252 
   1253 // atomic_load_explicit
   1254 
   1255 template <class _Tp>
   1256 inline _LIBCPP_INLINE_VISIBILITY
   1257 _Tp
   1258 atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
   1259   _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
   1260 {
   1261     return __o->load(__m);
   1262 }
   1263 
   1264 template <class _Tp>
   1265 inline _LIBCPP_INLINE_VISIBILITY
   1266 _Tp
   1267 atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
   1268   _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
   1269 {
   1270     return __o->load(__m);
   1271 }
   1272 
   1273 // atomic_exchange
   1274 
   1275 template <class _Tp>
   1276 inline _LIBCPP_INLINE_VISIBILITY
   1277 _Tp
   1278 atomic_exchange(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
   1279 {
   1280     return __o->exchange(__d);
   1281 }
   1282 
   1283 template <class _Tp>
   1284 inline _LIBCPP_INLINE_VISIBILITY
   1285 _Tp
   1286 atomic_exchange(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
   1287 {
   1288     return __o->exchange(__d);
   1289 }
   1290 
   1291 // atomic_exchange_explicit
   1292 
   1293 template <class _Tp>
   1294 inline _LIBCPP_INLINE_VISIBILITY
   1295 _Tp
   1296 atomic_exchange_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
   1297 {
   1298     return __o->exchange(__d, __m);
   1299 }
   1300 
   1301 template <class _Tp>
   1302 inline _LIBCPP_INLINE_VISIBILITY
   1303 _Tp
   1304 atomic_exchange_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
   1305 {
   1306     return __o->exchange(__d, __m);
   1307 }
   1308 
   1309 // atomic_compare_exchange_weak
   1310 
   1311 template <class _Tp>
   1312 inline _LIBCPP_INLINE_VISIBILITY
   1313 bool
   1314 atomic_compare_exchange_weak(volatile atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
   1315 {
   1316     return __o->compare_exchange_weak(*__e, __d);
   1317 }
   1318 
   1319 template <class _Tp>
   1320 inline _LIBCPP_INLINE_VISIBILITY
   1321 bool
   1322 atomic_compare_exchange_weak(atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
   1323 {
   1324     return __o->compare_exchange_weak(*__e, __d);
   1325 }
   1326 
   1327 // atomic_compare_exchange_strong
   1328 
   1329 template <class _Tp>
   1330 inline _LIBCPP_INLINE_VISIBILITY
   1331 bool
   1332 atomic_compare_exchange_strong(volatile atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
   1333 {
   1334     return __o->compare_exchange_strong(*__e, __d);
   1335 }
   1336 
   1337 template <class _Tp>
   1338 inline _LIBCPP_INLINE_VISIBILITY
   1339 bool
   1340 atomic_compare_exchange_strong(atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
   1341 {
   1342     return __o->compare_exchange_strong(*__e, __d);
   1343 }
   1344 
   1345 // atomic_compare_exchange_weak_explicit
   1346 
   1347 template <class _Tp>
   1348 inline _LIBCPP_INLINE_VISIBILITY
   1349 bool
   1350 atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, _Tp* __e,
   1351                                       _Tp __d,
   1352                                       memory_order __s, memory_order __f) _NOEXCEPT
   1353   _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
   1354 {
   1355     return __o->compare_exchange_weak(*__e, __d, __s, __f);
   1356 }
   1357 
   1358 template <class _Tp>
   1359 inline _LIBCPP_INLINE_VISIBILITY
   1360 bool
   1361 atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, _Tp* __e, _Tp __d,
   1362                                       memory_order __s, memory_order __f) _NOEXCEPT
   1363   _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
   1364 {
   1365     return __o->compare_exchange_weak(*__e, __d, __s, __f);
   1366 }
   1367 
   1368 // atomic_compare_exchange_strong_explicit
   1369 
   1370 template <class _Tp>
   1371 inline _LIBCPP_INLINE_VISIBILITY
   1372 bool
   1373 atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o,
   1374                                         _Tp* __e, _Tp __d,
   1375                                         memory_order __s, memory_order __f) _NOEXCEPT
   1376   _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
   1377 {
   1378     return __o->compare_exchange_strong(*__e, __d, __s, __f);
   1379 }
   1380 
   1381 template <class _Tp>
   1382 inline _LIBCPP_INLINE_VISIBILITY
   1383 bool
   1384 atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, _Tp* __e,
   1385                                         _Tp __d,
   1386                                         memory_order __s, memory_order __f) _NOEXCEPT
   1387   _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
   1388 {
   1389     return __o->compare_exchange_strong(*__e, __d, __s, __f);
   1390 }
   1391 
   1392 // atomic_fetch_add
   1393 
   1394 template <class _Tp>
   1395 inline _LIBCPP_INLINE_VISIBILITY
   1396 typename enable_if
   1397 <
   1398     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1399     _Tp
   1400 >::type
   1401 atomic_fetch_add(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1402 {
   1403     return __o->fetch_add(__op);
   1404 }
   1405 
   1406 template <class _Tp>
   1407 inline _LIBCPP_INLINE_VISIBILITY
   1408 typename enable_if
   1409 <
   1410     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1411     _Tp
   1412 >::type
   1413 atomic_fetch_add(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1414 {
   1415     return __o->fetch_add(__op);
   1416 }
   1417 
   1418 template <class _Tp>
   1419 inline _LIBCPP_INLINE_VISIBILITY
   1420 _Tp*
   1421 atomic_fetch_add(volatile atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
   1422 {
   1423     return __o->fetch_add(__op);
   1424 }
   1425 
   1426 template <class _Tp>
   1427 inline _LIBCPP_INLINE_VISIBILITY
   1428 _Tp*
   1429 atomic_fetch_add(atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
   1430 {
   1431     return __o->fetch_add(__op);
   1432 }
   1433 
   1434 // atomic_fetch_add_explicit
   1435 
   1436 template <class _Tp>
   1437 inline _LIBCPP_INLINE_VISIBILITY
   1438 typename enable_if
   1439 <
   1440     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1441     _Tp
   1442 >::type
   1443 atomic_fetch_add_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1444 {
   1445     return __o->fetch_add(__op, __m);
   1446 }
   1447 
   1448 template <class _Tp>
   1449 inline _LIBCPP_INLINE_VISIBILITY
   1450 typename enable_if
   1451 <
   1452     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1453     _Tp
   1454 >::type
   1455 atomic_fetch_add_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1456 {
   1457     return __o->fetch_add(__op, __m);
   1458 }
   1459 
   1460 template <class _Tp>
   1461 inline _LIBCPP_INLINE_VISIBILITY
   1462 _Tp*
   1463 atomic_fetch_add_explicit(volatile atomic<_Tp*>* __o, ptrdiff_t __op,
   1464                           memory_order __m) _NOEXCEPT
   1465 {
   1466     return __o->fetch_add(__op, __m);
   1467 }
   1468 
   1469 template <class _Tp>
   1470 inline _LIBCPP_INLINE_VISIBILITY
   1471 _Tp*
   1472 atomic_fetch_add_explicit(atomic<_Tp*>* __o, ptrdiff_t __op, memory_order __m) _NOEXCEPT
   1473 {
   1474     return __o->fetch_add(__op, __m);
   1475 }
   1476 
   1477 // atomic_fetch_sub
   1478 
   1479 template <class _Tp>
   1480 inline _LIBCPP_INLINE_VISIBILITY
   1481 typename enable_if
   1482 <
   1483     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1484     _Tp
   1485 >::type
   1486 atomic_fetch_sub(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1487 {
   1488     return __o->fetch_sub(__op);
   1489 }
   1490 
   1491 template <class _Tp>
   1492 inline _LIBCPP_INLINE_VISIBILITY
   1493 typename enable_if
   1494 <
   1495     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1496     _Tp
   1497 >::type
   1498 atomic_fetch_sub(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1499 {
   1500     return __o->fetch_sub(__op);
   1501 }
   1502 
   1503 template <class _Tp>
   1504 inline _LIBCPP_INLINE_VISIBILITY
   1505 _Tp*
   1506 atomic_fetch_sub(volatile atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
   1507 {
   1508     return __o->fetch_sub(__op);
   1509 }
   1510 
   1511 template <class _Tp>
   1512 inline _LIBCPP_INLINE_VISIBILITY
   1513 _Tp*
   1514 atomic_fetch_sub(atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
   1515 {
   1516     return __o->fetch_sub(__op);
   1517 }
   1518 
   1519 // atomic_fetch_sub_explicit
   1520 
   1521 template <class _Tp>
   1522 inline _LIBCPP_INLINE_VISIBILITY
   1523 typename enable_if
   1524 <
   1525     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1526     _Tp
   1527 >::type
   1528 atomic_fetch_sub_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1529 {
   1530     return __o->fetch_sub(__op, __m);
   1531 }
   1532 
   1533 template <class _Tp>
   1534 inline _LIBCPP_INLINE_VISIBILITY
   1535 typename enable_if
   1536 <
   1537     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1538     _Tp
   1539 >::type
   1540 atomic_fetch_sub_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1541 {
   1542     return __o->fetch_sub(__op, __m);
   1543 }
   1544 
   1545 template <class _Tp>
   1546 inline _LIBCPP_INLINE_VISIBILITY
   1547 _Tp*
   1548 atomic_fetch_sub_explicit(volatile atomic<_Tp*>* __o, ptrdiff_t __op,
   1549                           memory_order __m) _NOEXCEPT
   1550 {
   1551     return __o->fetch_sub(__op, __m);
   1552 }
   1553 
   1554 template <class _Tp>
   1555 inline _LIBCPP_INLINE_VISIBILITY
   1556 _Tp*
   1557 atomic_fetch_sub_explicit(atomic<_Tp*>* __o, ptrdiff_t __op, memory_order __m) _NOEXCEPT
   1558 {
   1559     return __o->fetch_sub(__op, __m);
   1560 }
   1561 
   1562 // atomic_fetch_and
   1563 
   1564 template <class _Tp>
   1565 inline _LIBCPP_INLINE_VISIBILITY
   1566 typename enable_if
   1567 <
   1568     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1569     _Tp
   1570 >::type
   1571 atomic_fetch_and(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1572 {
   1573     return __o->fetch_and(__op);
   1574 }
   1575 
   1576 template <class _Tp>
   1577 inline _LIBCPP_INLINE_VISIBILITY
   1578 typename enable_if
   1579 <
   1580     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1581     _Tp
   1582 >::type
   1583 atomic_fetch_and(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1584 {
   1585     return __o->fetch_and(__op);
   1586 }
   1587 
   1588 // atomic_fetch_and_explicit
   1589 
   1590 template <class _Tp>
   1591 inline _LIBCPP_INLINE_VISIBILITY
   1592 typename enable_if
   1593 <
   1594     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1595     _Tp
   1596 >::type
   1597 atomic_fetch_and_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1598 {
   1599     return __o->fetch_and(__op, __m);
   1600 }
   1601 
   1602 template <class _Tp>
   1603 inline _LIBCPP_INLINE_VISIBILITY
   1604 typename enable_if
   1605 <
   1606     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1607     _Tp
   1608 >::type
   1609 atomic_fetch_and_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1610 {
   1611     return __o->fetch_and(__op, __m);
   1612 }
   1613 
   1614 // atomic_fetch_or
   1615 
   1616 template <class _Tp>
   1617 inline _LIBCPP_INLINE_VISIBILITY
   1618 typename enable_if
   1619 <
   1620     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1621     _Tp
   1622 >::type
   1623 atomic_fetch_or(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1624 {
   1625     return __o->fetch_or(__op);
   1626 }
   1627 
   1628 template <class _Tp>
   1629 inline _LIBCPP_INLINE_VISIBILITY
   1630 typename enable_if
   1631 <
   1632     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1633     _Tp
   1634 >::type
   1635 atomic_fetch_or(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1636 {
   1637     return __o->fetch_or(__op);
   1638 }
   1639 
   1640 // atomic_fetch_or_explicit
   1641 
   1642 template <class _Tp>
   1643 inline _LIBCPP_INLINE_VISIBILITY
   1644 typename enable_if
   1645 <
   1646     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1647     _Tp
   1648 >::type
   1649 atomic_fetch_or_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1650 {
   1651     return __o->fetch_or(__op, __m);
   1652 }
   1653 
   1654 template <class _Tp>
   1655 inline _LIBCPP_INLINE_VISIBILITY
   1656 typename enable_if
   1657 <
   1658     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1659     _Tp
   1660 >::type
   1661 atomic_fetch_or_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1662 {
   1663     return __o->fetch_or(__op, __m);
   1664 }
   1665 
   1666 // atomic_fetch_xor
   1667 
   1668 template <class _Tp>
   1669 inline _LIBCPP_INLINE_VISIBILITY
   1670 typename enable_if
   1671 <
   1672     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1673     _Tp
   1674 >::type
   1675 atomic_fetch_xor(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1676 {
   1677     return __o->fetch_xor(__op);
   1678 }
   1679 
   1680 template <class _Tp>
   1681 inline _LIBCPP_INLINE_VISIBILITY
   1682 typename enable_if
   1683 <
   1684     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1685     _Tp
   1686 >::type
   1687 atomic_fetch_xor(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
   1688 {
   1689     return __o->fetch_xor(__op);
   1690 }
   1691 
   1692 // atomic_fetch_xor_explicit
   1693 
   1694 template <class _Tp>
   1695 inline _LIBCPP_INLINE_VISIBILITY
   1696 typename enable_if
   1697 <
   1698     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1699     _Tp
   1700 >::type
   1701 atomic_fetch_xor_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1702 {
   1703     return __o->fetch_xor(__op, __m);
   1704 }
   1705 
   1706 template <class _Tp>
   1707 inline _LIBCPP_INLINE_VISIBILITY
   1708 typename enable_if
   1709 <
   1710     is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
   1711     _Tp
   1712 >::type
   1713 atomic_fetch_xor_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
   1714 {
   1715     return __o->fetch_xor(__op, __m);
   1716 }
   1717 
   1718 // flag type and operations
   1719 
   1720 typedef struct atomic_flag
   1721 {
   1722     _Atomic(bool) __a_;
   1723 
   1724     _LIBCPP_INLINE_VISIBILITY
   1725     bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1726         {return __c11_atomic_exchange(&__a_, true, __m);}
   1727     _LIBCPP_INLINE_VISIBILITY
   1728     bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1729         {return __c11_atomic_exchange(&__a_, true, __m);}
   1730     _LIBCPP_INLINE_VISIBILITY
   1731     void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
   1732         {__c11_atomic_store(&__a_, false, __m);}
   1733     _LIBCPP_INLINE_VISIBILITY
   1734     void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT
   1735         {__c11_atomic_store(&__a_, false, __m);}
   1736 
   1737     _LIBCPP_INLINE_VISIBILITY
   1738 #ifndef _LIBCPP_CXX03_LANG
   1739     atomic_flag() _NOEXCEPT = default;
   1740 #else
   1741     atomic_flag() _NOEXCEPT : __a_() {}
   1742 #endif // _LIBCPP_CXX03_LANG
   1743 
   1744     _LIBCPP_INLINE_VISIBILITY
   1745     atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {} // EXTENSION
   1746 
   1747 #ifndef _LIBCPP_CXX03_LANG
   1748     atomic_flag(const atomic_flag&) = delete;
   1749     atomic_flag& operator=(const atomic_flag&) = delete;
   1750     atomic_flag& operator=(const atomic_flag&) volatile = delete;
   1751 #else
   1752 private:
   1753     atomic_flag(const atomic_flag&);
   1754     atomic_flag& operator=(const atomic_flag&);
   1755     atomic_flag& operator=(const atomic_flag&) volatile;
   1756 #endif
   1757 } atomic_flag;
   1758 
   1759 inline _LIBCPP_INLINE_VISIBILITY
   1760 bool
   1761 atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT
   1762 {
   1763     return __o->test_and_set();
   1764 }
   1765 
   1766 inline _LIBCPP_INLINE_VISIBILITY
   1767 bool
   1768 atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT
   1769 {
   1770     return __o->test_and_set();
   1771 }
   1772 
   1773 inline _LIBCPP_INLINE_VISIBILITY
   1774 bool
   1775 atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
   1776 {
   1777     return __o->test_and_set(__m);
   1778 }
   1779 
   1780 inline _LIBCPP_INLINE_VISIBILITY
   1781 bool
   1782 atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
   1783 {
   1784     return __o->test_and_set(__m);
   1785 }
   1786 
   1787 inline _LIBCPP_INLINE_VISIBILITY
   1788 void
   1789 atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT
   1790 {
   1791     __o->clear();
   1792 }
   1793 
   1794 inline _LIBCPP_INLINE_VISIBILITY
   1795 void
   1796 atomic_flag_clear(atomic_flag* __o) _NOEXCEPT
   1797 {
   1798     __o->clear();
   1799 }
   1800 
   1801 inline _LIBCPP_INLINE_VISIBILITY
   1802 void
   1803 atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
   1804 {
   1805     __o->clear(__m);
   1806 }
   1807 
   1808 inline _LIBCPP_INLINE_VISIBILITY
   1809 void
   1810 atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
   1811 {
   1812     __o->clear(__m);
   1813 }
   1814 
   1815 // fences
   1816 
   1817 inline _LIBCPP_INLINE_VISIBILITY
   1818 void
   1819 atomic_thread_fence(memory_order __m) _NOEXCEPT
   1820 {
   1821     __c11_atomic_thread_fence(__m);
   1822 }
   1823 
   1824 inline _LIBCPP_INLINE_VISIBILITY
   1825 void
   1826 atomic_signal_fence(memory_order __m) _NOEXCEPT
   1827 {
   1828     __c11_atomic_signal_fence(__m);
   1829 }
   1830 
   1831 // Atomics for standard typedef types
   1832 
   1833 typedef atomic<bool>               atomic_bool;
   1834 typedef atomic<char>               atomic_char;
   1835 typedef atomic<signed char>        atomic_schar;
   1836 typedef atomic<unsigned char>      atomic_uchar;
   1837 typedef atomic<short>              atomic_short;
   1838 typedef atomic<unsigned short>     atomic_ushort;
   1839 typedef atomic<int>                atomic_int;
   1840 typedef atomic<unsigned int>       atomic_uint;
   1841 typedef atomic<long>               atomic_long;
   1842 typedef atomic<unsigned long>      atomic_ulong;
   1843 typedef atomic<long long>          atomic_llong;
   1844 typedef atomic<unsigned long long> atomic_ullong;
   1845 typedef atomic<char16_t>           atomic_char16_t;
   1846 typedef atomic<char32_t>           atomic_char32_t;
   1847 typedef atomic<wchar_t>            atomic_wchar_t;
   1848 
   1849 typedef atomic<int_least8_t>   atomic_int_least8_t;
   1850 typedef atomic<uint_least8_t>  atomic_uint_least8_t;
   1851 typedef atomic<int_least16_t>  atomic_int_least16_t;
   1852 typedef atomic<uint_least16_t> atomic_uint_least16_t;
   1853 typedef atomic<int_least32_t>  atomic_int_least32_t;
   1854 typedef atomic<uint_least32_t> atomic_uint_least32_t;
   1855 typedef atomic<int_least64_t>  atomic_int_least64_t;
   1856 typedef atomic<uint_least64_t> atomic_uint_least64_t;
   1857 
   1858 typedef atomic<int_fast8_t>   atomic_int_fast8_t;
   1859 typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
   1860 typedef atomic<int_fast16_t>  atomic_int_fast16_t;
   1861 typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
   1862 typedef atomic<int_fast32_t>  atomic_int_fast32_t;
   1863 typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
   1864 typedef atomic<int_fast64_t>  atomic_int_fast64_t;
   1865 typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
   1866 
   1867 typedef atomic< int8_t>  atomic_int8_t;
   1868 typedef atomic<uint8_t>  atomic_uint8_t;
   1869 typedef atomic< int16_t> atomic_int16_t;
   1870 typedef atomic<uint16_t> atomic_uint16_t;
   1871 typedef atomic< int32_t> atomic_int32_t;
   1872 typedef atomic<uint32_t> atomic_uint32_t;
   1873 typedef atomic< int64_t> atomic_int64_t;
   1874 typedef atomic<uint64_t> atomic_uint64_t;
   1875 
   1876 typedef atomic<intptr_t>  atomic_intptr_t;
   1877 typedef atomic<uintptr_t> atomic_uintptr_t;
   1878 typedef atomic<size_t>    atomic_size_t;
   1879 typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
   1880 typedef atomic<intmax_t>  atomic_intmax_t;
   1881 typedef atomic<uintmax_t> atomic_uintmax_t;
   1882 
   1883 #define ATOMIC_FLAG_INIT {false}
   1884 #define ATOMIC_VAR_INIT(__v) {__v}
   1885 
   1886 _LIBCPP_END_NAMESPACE_STD
   1887 
   1888 #endif  // _LIBCPP_ATOMIC
   1889