xref: /freebsd/contrib/llvm-project/libcxx/include/atomic (revision 7d91d6b83e74edf278dde375e6049aca833cbebd)
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-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_ATOMIC
11#define _LIBCPP_ATOMIC
12
13/*
14    atomic synopsis
15
16namespace std
17{
18
19// feature test macro [version.syn]
20
21#define __cpp_lib_atomic_is_always_lock_free
22#define __cpp_lib_atomic_flag_test
23#define __cpp_lib_atomic_lock_free_type_aliases
24#define __cpp_lib_atomic_wait
25
26 // order and consistency
27
28 enum memory_order: unspecified // enum class in C++20
29 {
30    relaxed,
31    consume, // load-consume
32    acquire, // load-acquire
33    release, // store-release
34    acq_rel, // store-release load-acquire
35    seq_cst // store-release load-acquire
36 };
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 property
48
49#define ATOMIC_BOOL_LOCK_FREE unspecified
50#define ATOMIC_CHAR_LOCK_FREE unspecified
51#define ATOMIC_CHAR8_T_LOCK_FREE unspecified // C++20
52#define ATOMIC_CHAR16_T_LOCK_FREE unspecified
53#define ATOMIC_CHAR32_T_LOCK_FREE unspecified
54#define ATOMIC_WCHAR_T_LOCK_FREE unspecified
55#define ATOMIC_SHORT_LOCK_FREE unspecified
56#define ATOMIC_INT_LOCK_FREE unspecified
57#define ATOMIC_LONG_LOCK_FREE unspecified
58#define ATOMIC_LLONG_LOCK_FREE unspecified
59#define ATOMIC_POINTER_LOCK_FREE unspecified
60
61template <class T>
62struct atomic
63{
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++20
71    constexpr atomic() noexcept(is_nothrow_default_constructible_v<T>); // since C++20
72    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;
105    void wait(T, memory_order = memory_order::seq_cst) const noexcept;
106    void notify_one() volatile noexcept;
107    void notify_one() noexcept;
108    void notify_all() volatile noexcept;
109    void notify_all() noexcept;
110};
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;
188    void wait(integral, memory_order = memory_order::seq_cst) const noexcept;
189    void notify_one() volatile noexcept;
190    void notify_one() noexcept;
191    void notify_all() volatile noexcept;
192    void notify_all() noexcept;
193};
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++20
206    constexpr atomic() noexcept; // since C++20
207    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;
258    void wait(T*, memory_order = memory_order::seq_cst) const noexcept;
259    void notify_one() volatile noexcept;
260    void notify_one() noexcept;
261    void notify_all() volatile noexcept;
262    void notify_all() noexcept;
263};
264
265
266// [atomics.nonmembers], non-member functions
267template<class T>
268  bool atomic_is_lock_free(const volatile atomic<T>*) noexcept;
269template<class T>
270  bool atomic_is_lock_free(const atomic<T>*) noexcept;
271template<class T>
272  void atomic_store(volatile atomic<T>*, atomic<T>::value_type) noexcept;
273template<class T>
274  void atomic_store(atomic<T>*, atomic<T>::value_type) noexcept;
275template<class T>
276  void atomic_store_explicit(volatile atomic<T>*, atomic<T>::value_type,
277                             memory_order) noexcept;
278template<class T>
279  void atomic_store_explicit(atomic<T>*, atomic<T>::value_type,
280                             memory_order) noexcept;
281template<class T>
282  T atomic_load(const volatile atomic<T>*) noexcept;
283template<class T>
284  T atomic_load(const atomic<T>*) noexcept;
285template<class T>
286  T atomic_load_explicit(const volatile atomic<T>*, memory_order) noexcept;
287template<class T>
288  T atomic_load_explicit(const atomic<T>*, memory_order) noexcept;
289template<class T>
290  T atomic_exchange(volatile atomic<T>*, atomic<T>::value_type) noexcept;
291template<class T>
292  T atomic_exchange(atomic<T>*, atomic<T>::value_type) noexcept;
293template<class T>
294  T atomic_exchange_explicit(volatile atomic<T>*, atomic<T>::value_type,
295                             memory_order) noexcept;
296template<class T>
297  T atomic_exchange_explicit(atomic<T>*, atomic<T>::value_type,
298                             memory_order) noexcept;
299template<class T>
300  bool atomic_compare_exchange_weak(volatile atomic<T>*, atomic<T>::value_type*,
301                                    atomic<T>::value_type) noexcept;
302template<class T>
303  bool atomic_compare_exchange_weak(atomic<T>*, atomic<T>::value_type*,
304                                    atomic<T>::value_type) noexcept;
305template<class T>
306  bool atomic_compare_exchange_strong(volatile atomic<T>*, atomic<T>::value_type*,
307                                      atomic<T>::value_type) noexcept;
308template<class T>
309  bool atomic_compare_exchange_strong(atomic<T>*, atomic<T>::value_type*,
310                                      atomic<T>::value_type) noexcept;
311template<class T>
312  bool atomic_compare_exchange_weak_explicit(volatile atomic<T>*, atomic<T>::value_type*,
313                                             atomic<T>::value_type,
314                                             memory_order, memory_order) noexcept;
315template<class T>
316  bool atomic_compare_exchange_weak_explicit(atomic<T>*, atomic<T>::value_type*,
317                                             atomic<T>::value_type,
318                                             memory_order, memory_order) noexcept;
319template<class T>
320  bool atomic_compare_exchange_strong_explicit(volatile atomic<T>*, atomic<T>::value_type*,
321                                               atomic<T>::value_type,
322                                               memory_order, memory_order) noexcept;
323template<class T>
324  bool atomic_compare_exchange_strong_explicit(atomic<T>*, atomic<T>::value_type*,
325                                               atomic<T>::value_type,
326                                               memory_order, memory_order) noexcept;
327
328template<class T>
329  T atomic_fetch_add(volatile atomic<T>*, atomic<T>::difference_type) noexcept;
330template<class T>
331  T atomic_fetch_add(atomic<T>*, atomic<T>::difference_type) noexcept;
332template<class T>
333  T atomic_fetch_add_explicit(volatile atomic<T>*, atomic<T>::difference_type,
334                              memory_order) noexcept;
335template<class T>
336  T atomic_fetch_add_explicit(atomic<T>*, atomic<T>::difference_type,
337                              memory_order) noexcept;
338template<class T>
339  T atomic_fetch_sub(volatile atomic<T>*, atomic<T>::difference_type) noexcept;
340template<class T>
341  T atomic_fetch_sub(atomic<T>*, atomic<T>::difference_type) noexcept;
342template<class T>
343  T atomic_fetch_sub_explicit(volatile atomic<T>*, atomic<T>::difference_type,
344                              memory_order) noexcept;
345template<class T>
346  T atomic_fetch_sub_explicit(atomic<T>*, atomic<T>::difference_type,
347                              memory_order) noexcept;
348template<class T>
349  T atomic_fetch_and(volatile atomic<T>*, atomic<T>::value_type) noexcept;
350template<class T>
351  T atomic_fetch_and(atomic<T>*, atomic<T>::value_type) noexcept;
352template<class T>
353  T atomic_fetch_and_explicit(volatile atomic<T>*, atomic<T>::value_type,
354                              memory_order) noexcept;
355template<class T>
356  T atomic_fetch_and_explicit(atomic<T>*, atomic<T>::value_type,
357                              memory_order) noexcept;
358template<class T>
359  T atomic_fetch_or(volatile atomic<T>*, atomic<T>::value_type) noexcept;
360template<class T>
361  T atomic_fetch_or(atomic<T>*, atomic<T>::value_type) noexcept;
362template<class T>
363  T atomic_fetch_or_explicit(volatile atomic<T>*, atomic<T>::value_type,
364                             memory_order) noexcept;
365template<class T>
366  T atomic_fetch_or_explicit(atomic<T>*, atomic<T>::value_type,
367                             memory_order) noexcept;
368template<class T>
369  T atomic_fetch_xor(volatile atomic<T>*, atomic<T>::value_type) noexcept;
370template<class T>
371  T atomic_fetch_xor(atomic<T>*, atomic<T>::value_type) noexcept;
372template<class T>
373  T atomic_fetch_xor_explicit(volatile atomic<T>*, atomic<T>::value_type,
374                              memory_order) noexcept;
375template<class T>
376  T atomic_fetch_xor_explicit(atomic<T>*, atomic<T>::value_type,
377                              memory_order) noexcept;
378
379template<class T>
380  void atomic_wait(const volatile atomic<T>*, atomic<T>::value_type);
381template<class T>
382  void atomic_wait(const atomic<T>*, atomic<T>::value_type);
383template<class T>
384  void atomic_wait_explicit(const volatile atomic<T>*, atomic<T>::value_type,
385                            memory_order);
386template<class T>
387  void atomic_wait_explicit(const atomic<T>*, atomic<T>::value_type,
388                            memory_order);
389template<class T>
390  void atomic_notify_one(volatile atomic<T>*);
391template<class T>
392  void atomic_notify_one(atomic<T>*);
393template<class T>
394  void atomic_notify_all(volatile atomic<T>*);
395template<class T>
396  void atomic_notify_all(atomic<T>*);
397
398// Atomics for standard typedef types
399
400typedef atomic<bool>               atomic_bool;
401typedef atomic<char>               atomic_char;
402typedef atomic<signed char>        atomic_schar;
403typedef atomic<unsigned char>      atomic_uchar;
404typedef atomic<short>              atomic_short;
405typedef atomic<unsigned short>     atomic_ushort;
406typedef atomic<int>                atomic_int;
407typedef atomic<unsigned int>       atomic_uint;
408typedef atomic<long>               atomic_long;
409typedef atomic<unsigned long>      atomic_ulong;
410typedef atomic<long long>          atomic_llong;
411typedef atomic<unsigned long long> atomic_ullong;
412typedef atomic<char8_t>            atomic_char8_t; // C++20
413typedef atomic<char16_t>           atomic_char16_t;
414typedef atomic<char32_t>           atomic_char32_t;
415typedef atomic<wchar_t>            atomic_wchar_t;
416
417typedef atomic<int_least8_t>   atomic_int_least8_t;
418typedef atomic<uint_least8_t>  atomic_uint_least8_t;
419typedef atomic<int_least16_t>  atomic_int_least16_t;
420typedef atomic<uint_least16_t> atomic_uint_least16_t;
421typedef atomic<int_least32_t>  atomic_int_least32_t;
422typedef atomic<uint_least32_t> atomic_uint_least32_t;
423typedef atomic<int_least64_t>  atomic_int_least64_t;
424typedef atomic<uint_least64_t> atomic_uint_least64_t;
425
426typedef atomic<int_fast8_t>   atomic_int_fast8_t;
427typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
428typedef atomic<int_fast16_t>  atomic_int_fast16_t;
429typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
430typedef atomic<int_fast32_t>  atomic_int_fast32_t;
431typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
432typedef atomic<int_fast64_t>  atomic_int_fast64_t;
433typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
434
435typedef atomic<int8_t>   atomic_int8_t;
436typedef atomic<uint8_t>  atomic_uint8_t;
437typedef atomic<int16_t>  atomic_int16_t;
438typedef atomic<uint16_t> atomic_uint16_t;
439typedef atomic<int32_t>  atomic_int32_t;
440typedef atomic<uint32_t> atomic_uint32_t;
441typedef atomic<int64_t>  atomic_int64_t;
442typedef atomic<uint64_t> atomic_uint64_t;
443
444typedef atomic<intptr_t>  atomic_intptr_t;
445typedef atomic<uintptr_t> atomic_uintptr_t;
446typedef atomic<size_t>    atomic_size_t;
447typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
448typedef atomic<intmax_t>  atomic_intmax_t;
449typedef atomic<uintmax_t> atomic_uintmax_t;
450
451// flag type and operations
452
453typedef struct atomic_flag
454{
455    atomic_flag() noexcept = default; // until C++20
456    constexpr atomic_flag() noexcept; // since C++20
457    atomic_flag(const atomic_flag&) = delete;
458    atomic_flag& operator=(const atomic_flag&) = delete;
459    atomic_flag& operator=(const atomic_flag&) volatile = delete;
460
461    bool test(memory_order m = memory_order_seq_cst) volatile noexcept;
462    bool test(memory_order m = memory_order_seq_cst) noexcept;
463    bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept;
464    bool test_and_set(memory_order m = memory_order_seq_cst) noexcept;
465    void clear(memory_order m = memory_order_seq_cst) volatile noexcept;
466    void clear(memory_order m = memory_order_seq_cst) noexcept;
467
468    void wait(bool, memory_order = memory_order::seq_cst) const volatile noexcept;
469    void wait(bool, memory_order = memory_order::seq_cst) const noexcept;
470    void notify_one() volatile noexcept;
471    void notify_one() noexcept;
472    void notify_all() volatile noexcept;
473    void notify_all() noexcept;
474} atomic_flag;
475
476bool atomic_flag_test(volatile atomic_flag* obj) noexcept;
477bool atomic_flag_test(atomic_flag* obj) noexcept;
478bool atomic_flag_test_explicit(volatile atomic_flag* obj,
479                               memory_order m) noexcept;
480bool atomic_flag_test_explicit(atomic_flag* obj, memory_order m) noexcept;
481bool atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept;
482bool atomic_flag_test_and_set(atomic_flag* obj) noexcept;
483bool atomic_flag_test_and_set_explicit(volatile atomic_flag* obj,
484                                       memory_order m) noexcept;
485bool atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept;
486void atomic_flag_clear(volatile atomic_flag* obj) noexcept;
487void atomic_flag_clear(atomic_flag* obj) noexcept;
488void atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept;
489void atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept;
490
491void atomic_wait(const volatile atomic_flag* obj, T old) noexcept;
492void atomic_wait(const atomic_flag* obj, T old) noexcept;
493void atomic_wait_explicit(const volatile atomic_flag* obj, T old, memory_order m) noexcept;
494void atomic_wait_explicit(const atomic_flag* obj, T old, memory_order m) noexcept;
495void atomic_one(volatile atomic_flag* obj) noexcept;
496void atomic_one(atomic_flag* obj) noexcept;
497void atomic_all(volatile atomic_flag* obj) noexcept;
498void atomic_all(atomic_flag* obj) noexcept;
499
500// fences
501
502void atomic_thread_fence(memory_order m) noexcept;
503void atomic_signal_fence(memory_order m) noexcept;
504
505// deprecated
506
507template <class T>
508  void atomic_init(volatile atomic<T>* obj, atomic<T>::value_type desr) noexcept;
509
510template <class T>
511  void atomic_init(atomic<T>* obj, atomic<T>::value_type desr) noexcept;
512
513#define ATOMIC_VAR_INIT(value) see below
514
515#define ATOMIC_FLAG_INIT see below
516
517}  // std
518
519*/
520
521#include <__availability>
522#include <__config>
523#include <__thread/poll_with_backoff.h>
524#include <__thread/timed_backoff_policy.h>
525#include <cstddef>
526#include <cstdint>
527#include <cstring>
528#include <type_traits>
529#include <version>
530
531#ifndef _LIBCPP_HAS_NO_THREADS
532# include <__threading_support>
533#endif
534
535#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
536#pragma GCC system_header
537#endif
538
539#ifdef _LIBCPP_HAS_NO_ATOMIC_HEADER
540# error <atomic> is not implemented
541#endif
542#ifdef kill_dependency
543# error C++ standard library is incompatible with <stdatomic.h>
544#endif
545
546#define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \
547  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \
548                           __m == memory_order_acquire || \
549                           __m == memory_order_acq_rel,   \
550                        "memory order argument to atomic operation is invalid")
551
552#define _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) \
553  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_release || \
554                           __m == memory_order_acq_rel,   \
555                        "memory order argument to atomic operation is invalid")
556
557#define _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__m, __f) \
558  _LIBCPP_DIAGNOSE_WARNING(__f == memory_order_release || \
559                           __f == memory_order_acq_rel,   \
560                        "memory order argument to atomic operation is invalid")
561
562_LIBCPP_BEGIN_NAMESPACE_STD
563
564// Figure out what the underlying type for `memory_order` would be if it were
565// declared as an unscoped enum (accounting for -fshort-enums). Use this result
566// to pin the underlying type in C++20.
567enum __legacy_memory_order {
568    __mo_relaxed,
569    __mo_consume,
570    __mo_acquire,
571    __mo_release,
572    __mo_acq_rel,
573    __mo_seq_cst
574};
575
576typedef underlying_type<__legacy_memory_order>::type __memory_order_underlying_t;
577
578#if _LIBCPP_STD_VER > 17
579
580enum class memory_order : __memory_order_underlying_t {
581  relaxed = __mo_relaxed,
582  consume = __mo_consume,
583  acquire = __mo_acquire,
584  release = __mo_release,
585  acq_rel = __mo_acq_rel,
586  seq_cst = __mo_seq_cst
587};
588
589inline constexpr auto memory_order_relaxed = memory_order::relaxed;
590inline constexpr auto memory_order_consume = memory_order::consume;
591inline constexpr auto memory_order_acquire = memory_order::acquire;
592inline constexpr auto memory_order_release = memory_order::release;
593inline constexpr auto memory_order_acq_rel = memory_order::acq_rel;
594inline constexpr auto memory_order_seq_cst = memory_order::seq_cst;
595
596#else
597
598typedef enum memory_order {
599  memory_order_relaxed = __mo_relaxed,
600  memory_order_consume = __mo_consume,
601  memory_order_acquire = __mo_acquire,
602  memory_order_release = __mo_release,
603  memory_order_acq_rel = __mo_acq_rel,
604  memory_order_seq_cst = __mo_seq_cst,
605} memory_order;
606
607#endif // _LIBCPP_STD_VER > 17
608
609template <typename _Tp> _LIBCPP_INLINE_VISIBILITY
610bool __cxx_nonatomic_compare_equal(_Tp const& __lhs, _Tp const& __rhs) {
611    return _VSTD::memcmp(&__lhs, &__rhs, sizeof(_Tp)) == 0;
612}
613
614static_assert((is_same<underlying_type<memory_order>::type, __memory_order_underlying_t>::value),
615  "unexpected underlying type for std::memory_order");
616
617#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) || \
618    defined(_LIBCPP_ATOMIC_ONLY_USE_BUILTINS)
619
620// [atomics.types.generic]p1 guarantees _Tp is trivially copyable. Because
621// the default operator= in an object is not volatile, a byte-by-byte copy
622// is required.
623template <typename _Tp, typename _Tv> _LIBCPP_INLINE_VISIBILITY
624typename enable_if<is_assignable<_Tp&, _Tv>::value>::type
625__cxx_atomic_assign_volatile(_Tp& __a_value, _Tv const& __val) {
626  __a_value = __val;
627}
628template <typename _Tp, typename _Tv> _LIBCPP_INLINE_VISIBILITY
629typename enable_if<is_assignable<_Tp&, _Tv>::value>::type
630__cxx_atomic_assign_volatile(_Tp volatile& __a_value, _Tv volatile const& __val) {
631  volatile char* __to = reinterpret_cast<volatile char*>(&__a_value);
632  volatile char* __end = __to + sizeof(_Tp);
633  volatile const char* __from = reinterpret_cast<volatile const char*>(&__val);
634  while (__to != __end)
635    *__to++ = *__from++;
636}
637
638#endif
639
640#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
641
642template <typename _Tp>
643struct __cxx_atomic_base_impl {
644
645  _LIBCPP_INLINE_VISIBILITY
646#ifndef _LIBCPP_CXX03_LANG
647    __cxx_atomic_base_impl() _NOEXCEPT = default;
648#else
649    __cxx_atomic_base_impl() _NOEXCEPT : __a_value() {}
650#endif // _LIBCPP_CXX03_LANG
651  _LIBCPP_CONSTEXPR explicit __cxx_atomic_base_impl(_Tp value) _NOEXCEPT
652    : __a_value(value) {}
653  _Tp __a_value;
654};
655
656_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR int __to_gcc_order(memory_order __order) {
657  // Avoid switch statement to make this a constexpr.
658  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
659         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
660          (__order == memory_order_release ? __ATOMIC_RELEASE:
661           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
662            (__order == memory_order_acq_rel ? __ATOMIC_ACQ_REL:
663              __ATOMIC_CONSUME))));
664}
665
666_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR int __to_gcc_failure_order(memory_order __order) {
667  // Avoid switch statement to make this a constexpr.
668  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
669         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
670          (__order == memory_order_release ? __ATOMIC_RELAXED:
671           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
672            (__order == memory_order_acq_rel ? __ATOMIC_ACQUIRE:
673              __ATOMIC_CONSUME))));
674}
675
676template <typename _Tp>
677_LIBCPP_INLINE_VISIBILITY
678void __cxx_atomic_init(volatile __cxx_atomic_base_impl<_Tp>* __a,  _Tp __val) {
679  __cxx_atomic_assign_volatile(__a->__a_value, __val);
680}
681
682template <typename _Tp>
683_LIBCPP_INLINE_VISIBILITY
684void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp>* __a,  _Tp __val) {
685  __a->__a_value = __val;
686}
687
688_LIBCPP_INLINE_VISIBILITY inline
689void __cxx_atomic_thread_fence(memory_order __order) {
690  __atomic_thread_fence(__to_gcc_order(__order));
691}
692
693_LIBCPP_INLINE_VISIBILITY inline
694void __cxx_atomic_signal_fence(memory_order __order) {
695  __atomic_signal_fence(__to_gcc_order(__order));
696}
697
698template <typename _Tp>
699_LIBCPP_INLINE_VISIBILITY
700void __cxx_atomic_store(volatile __cxx_atomic_base_impl<_Tp>* __a,  _Tp __val,
701                        memory_order __order) {
702  __atomic_store(&__a->__a_value, &__val,
703                 __to_gcc_order(__order));
704}
705
706template <typename _Tp>
707_LIBCPP_INLINE_VISIBILITY
708void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp>* __a,  _Tp __val,
709                        memory_order __order) {
710  __atomic_store(&__a->__a_value, &__val,
711                 __to_gcc_order(__order));
712}
713
714template <typename _Tp>
715_LIBCPP_INLINE_VISIBILITY
716_Tp __cxx_atomic_load(const volatile __cxx_atomic_base_impl<_Tp>* __a,
717                      memory_order __order) {
718  _Tp __ret;
719  __atomic_load(&__a->__a_value, &__ret,
720                __to_gcc_order(__order));
721  return __ret;
722}
723
724template <typename _Tp>
725_LIBCPP_INLINE_VISIBILITY
726_Tp __cxx_atomic_load(const __cxx_atomic_base_impl<_Tp>* __a, memory_order __order) {
727  _Tp __ret;
728  __atomic_load(&__a->__a_value, &__ret,
729                __to_gcc_order(__order));
730  return __ret;
731}
732
733template <typename _Tp>
734_LIBCPP_INLINE_VISIBILITY
735_Tp __cxx_atomic_exchange(volatile __cxx_atomic_base_impl<_Tp>* __a,
736                          _Tp __value, memory_order __order) {
737  _Tp __ret;
738  __atomic_exchange(&__a->__a_value, &__value, &__ret,
739                    __to_gcc_order(__order));
740  return __ret;
741}
742
743template <typename _Tp>
744_LIBCPP_INLINE_VISIBILITY
745_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp>* __a, _Tp __value,
746                          memory_order __order) {
747  _Tp __ret;
748  __atomic_exchange(&__a->__a_value, &__value, &__ret,
749                    __to_gcc_order(__order));
750  return __ret;
751}
752
753template <typename _Tp>
754_LIBCPP_INLINE_VISIBILITY
755bool __cxx_atomic_compare_exchange_strong(
756    volatile __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value,
757    memory_order __success, memory_order __failure) {
758  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
759                                   false,
760                                   __to_gcc_order(__success),
761                                   __to_gcc_failure_order(__failure));
762}
763
764template <typename _Tp>
765_LIBCPP_INLINE_VISIBILITY
766bool __cxx_atomic_compare_exchange_strong(
767    __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success,
768    memory_order __failure) {
769  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
770                                   false,
771                                   __to_gcc_order(__success),
772                                   __to_gcc_failure_order(__failure));
773}
774
775template <typename _Tp>
776_LIBCPP_INLINE_VISIBILITY
777bool __cxx_atomic_compare_exchange_weak(
778    volatile __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value,
779    memory_order __success, memory_order __failure) {
780  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
781                                   true,
782                                   __to_gcc_order(__success),
783                                   __to_gcc_failure_order(__failure));
784}
785
786template <typename _Tp>
787_LIBCPP_INLINE_VISIBILITY
788bool __cxx_atomic_compare_exchange_weak(
789    __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success,
790    memory_order __failure) {
791  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
792                                   true,
793                                   __to_gcc_order(__success),
794                                   __to_gcc_failure_order(__failure));
795}
796
797template <typename _Tp>
798struct __skip_amt { enum {value = 1}; };
799
800template <typename _Tp>
801struct __skip_amt<_Tp*> { enum {value = sizeof(_Tp)}; };
802
803// FIXME: Haven't figured out what the spec says about using arrays with
804// atomic_fetch_add. Force a failure rather than creating bad behavior.
805template <typename _Tp>
806struct __skip_amt<_Tp[]> { };
807template <typename _Tp, int n>
808struct __skip_amt<_Tp[n]> { };
809
810template <typename _Tp, typename _Td>
811_LIBCPP_INLINE_VISIBILITY
812_Tp __cxx_atomic_fetch_add(volatile __cxx_atomic_base_impl<_Tp>* __a,
813                           _Td __delta, memory_order __order) {
814  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
815                            __to_gcc_order(__order));
816}
817
818template <typename _Tp, typename _Td>
819_LIBCPP_INLINE_VISIBILITY
820_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp>* __a, _Td __delta,
821                           memory_order __order) {
822  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
823                            __to_gcc_order(__order));
824}
825
826template <typename _Tp, typename _Td>
827_LIBCPP_INLINE_VISIBILITY
828_Tp __cxx_atomic_fetch_sub(volatile __cxx_atomic_base_impl<_Tp>* __a,
829                           _Td __delta, memory_order __order) {
830  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
831                            __to_gcc_order(__order));
832}
833
834template <typename _Tp, typename _Td>
835_LIBCPP_INLINE_VISIBILITY
836_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp>* __a, _Td __delta,
837                           memory_order __order) {
838  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
839                            __to_gcc_order(__order));
840}
841
842template <typename _Tp>
843_LIBCPP_INLINE_VISIBILITY
844_Tp __cxx_atomic_fetch_and(volatile __cxx_atomic_base_impl<_Tp>* __a,
845                           _Tp __pattern, memory_order __order) {
846  return __atomic_fetch_and(&__a->__a_value, __pattern,
847                            __to_gcc_order(__order));
848}
849
850template <typename _Tp>
851_LIBCPP_INLINE_VISIBILITY
852_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp>* __a,
853                           _Tp __pattern, memory_order __order) {
854  return __atomic_fetch_and(&__a->__a_value, __pattern,
855                            __to_gcc_order(__order));
856}
857
858template <typename _Tp>
859_LIBCPP_INLINE_VISIBILITY
860_Tp __cxx_atomic_fetch_or(volatile __cxx_atomic_base_impl<_Tp>* __a,
861                          _Tp __pattern, memory_order __order) {
862  return __atomic_fetch_or(&__a->__a_value, __pattern,
863                           __to_gcc_order(__order));
864}
865
866template <typename _Tp>
867_LIBCPP_INLINE_VISIBILITY
868_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp>* __a, _Tp __pattern,
869                          memory_order __order) {
870  return __atomic_fetch_or(&__a->__a_value, __pattern,
871                           __to_gcc_order(__order));
872}
873
874template <typename _Tp>
875_LIBCPP_INLINE_VISIBILITY
876_Tp __cxx_atomic_fetch_xor(volatile __cxx_atomic_base_impl<_Tp>* __a,
877                           _Tp __pattern, memory_order __order) {
878  return __atomic_fetch_xor(&__a->__a_value, __pattern,
879                            __to_gcc_order(__order));
880}
881
882template <typename _Tp>
883_LIBCPP_INLINE_VISIBILITY
884_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp>* __a, _Tp __pattern,
885                           memory_order __order) {
886  return __atomic_fetch_xor(&__a->__a_value, __pattern,
887                            __to_gcc_order(__order));
888}
889
890#define __cxx_atomic_is_lock_free(__s) __atomic_is_lock_free(__s, 0)
891
892#elif defined(_LIBCPP_HAS_C_ATOMIC_IMP)
893
894template <typename _Tp>
895struct __cxx_atomic_base_impl {
896
897  _LIBCPP_INLINE_VISIBILITY
898#ifndef _LIBCPP_CXX03_LANG
899    __cxx_atomic_base_impl() _NOEXCEPT = default;
900#else
901    __cxx_atomic_base_impl() _NOEXCEPT : __a_value() {}
902#endif // _LIBCPP_CXX03_LANG
903  _LIBCPP_CONSTEXPR explicit __cxx_atomic_base_impl(_Tp value) _NOEXCEPT
904    : __a_value(value) {}
905  _LIBCPP_DISABLE_EXTENSION_WARNING _Atomic(_Tp) __a_value;
906};
907
908#define __cxx_atomic_is_lock_free(__s) __c11_atomic_is_lock_free(__s)
909
910_LIBCPP_INLINE_VISIBILITY inline
911void __cxx_atomic_thread_fence(memory_order __order) _NOEXCEPT {
912    __c11_atomic_thread_fence(static_cast<__memory_order_underlying_t>(__order));
913}
914
915_LIBCPP_INLINE_VISIBILITY inline
916void __cxx_atomic_signal_fence(memory_order __order) _NOEXCEPT {
917    __c11_atomic_signal_fence(static_cast<__memory_order_underlying_t>(__order));
918}
919
920template<class _Tp>
921_LIBCPP_INLINE_VISIBILITY
922void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __val) _NOEXCEPT {
923    __c11_atomic_init(&__a->__a_value, __val);
924}
925template<class _Tp>
926_LIBCPP_INLINE_VISIBILITY
927void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp> * __a, _Tp __val) _NOEXCEPT {
928    __c11_atomic_init(&__a->__a_value, __val);
929}
930
931template<class _Tp>
932_LIBCPP_INLINE_VISIBILITY
933void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __val, memory_order __order) _NOEXCEPT {
934    __c11_atomic_store(&__a->__a_value, __val, static_cast<__memory_order_underlying_t>(__order));
935}
936template<class _Tp>
937_LIBCPP_INLINE_VISIBILITY
938void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp> * __a, _Tp __val, memory_order __order) _NOEXCEPT {
939    __c11_atomic_store(&__a->__a_value, __val, static_cast<__memory_order_underlying_t>(__order));
940}
941
942template<class _Tp>
943_LIBCPP_INLINE_VISIBILITY
944_Tp __cxx_atomic_load(__cxx_atomic_base_impl<_Tp> const volatile* __a, memory_order __order) _NOEXCEPT {
945    using __ptr_type = typename remove_const<decltype(__a->__a_value)>::type*;
946    return __c11_atomic_load(const_cast<__ptr_type>(&__a->__a_value), static_cast<__memory_order_underlying_t>(__order));
947}
948template<class _Tp>
949_LIBCPP_INLINE_VISIBILITY
950_Tp __cxx_atomic_load(__cxx_atomic_base_impl<_Tp> const* __a, memory_order __order) _NOEXCEPT {
951    using __ptr_type = typename remove_const<decltype(__a->__a_value)>::type*;
952    return __c11_atomic_load(const_cast<__ptr_type>(&__a->__a_value), static_cast<__memory_order_underlying_t>(__order));
953}
954
955template<class _Tp>
956_LIBCPP_INLINE_VISIBILITY
957_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __value, memory_order __order) _NOEXCEPT {
958    return __c11_atomic_exchange(&__a->__a_value, __value, static_cast<__memory_order_underlying_t>(__order));
959}
960template<class _Tp>
961_LIBCPP_INLINE_VISIBILITY
962_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp> * __a, _Tp __value, memory_order __order) _NOEXCEPT {
963    return __c11_atomic_exchange(&__a->__a_value, __value, static_cast<__memory_order_underlying_t>(__order));
964}
965
966_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR memory_order __to_failure_order(memory_order __order) {
967  // Avoid switch statement to make this a constexpr.
968  return __order == memory_order_release ? memory_order_relaxed:
969         (__order == memory_order_acq_rel ? memory_order_acquire:
970             __order);
971}
972
973template<class _Tp>
974_LIBCPP_INLINE_VISIBILITY
975bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
976    return __c11_atomic_compare_exchange_strong(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
977}
978template<class _Tp>
979_LIBCPP_INLINE_VISIBILITY
980bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_base_impl<_Tp> * __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
981    return __c11_atomic_compare_exchange_strong(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
982}
983
984template<class _Tp>
985_LIBCPP_INLINE_VISIBILITY
986bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
987    return __c11_atomic_compare_exchange_weak(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
988}
989template<class _Tp>
990_LIBCPP_INLINE_VISIBILITY
991bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_base_impl<_Tp> * __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
992    return __c11_atomic_compare_exchange_weak(&__a->__a_value, __expected, __value,  static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
993}
994
995template<class _Tp>
996_LIBCPP_INLINE_VISIBILITY
997_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __delta, memory_order __order) _NOEXCEPT {
998    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
999}
1000template<class _Tp>
1001_LIBCPP_INLINE_VISIBILITY
1002_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp> * __a, _Tp __delta, memory_order __order) _NOEXCEPT {
1003    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1004}
1005
1006template<class _Tp>
1007_LIBCPP_INLINE_VISIBILITY
1008_Tp* __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
1009    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1010}
1011template<class _Tp>
1012_LIBCPP_INLINE_VISIBILITY
1013_Tp* __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp*> * __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
1014    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1015}
1016
1017template<class _Tp>
1018_LIBCPP_INLINE_VISIBILITY
1019_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __delta, memory_order __order) _NOEXCEPT {
1020    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1021}
1022template<class _Tp>
1023_LIBCPP_INLINE_VISIBILITY
1024_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp> * __a, _Tp __delta, memory_order __order) _NOEXCEPT {
1025    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1026}
1027template<class _Tp>
1028_LIBCPP_INLINE_VISIBILITY
1029_Tp* __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
1030    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1031}
1032template<class _Tp>
1033_LIBCPP_INLINE_VISIBILITY
1034_Tp* __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp*> * __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
1035    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
1036}
1037
1038template<class _Tp>
1039_LIBCPP_INLINE_VISIBILITY
1040_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
1041    return __c11_atomic_fetch_and(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
1042}
1043template<class _Tp>
1044_LIBCPP_INLINE_VISIBILITY
1045_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
1046    return __c11_atomic_fetch_and(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
1047}
1048
1049template<class _Tp>
1050_LIBCPP_INLINE_VISIBILITY
1051_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
1052    return __c11_atomic_fetch_or(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
1053}
1054template<class _Tp>
1055_LIBCPP_INLINE_VISIBILITY
1056_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
1057    return __c11_atomic_fetch_or(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
1058}
1059
1060template<class _Tp>
1061_LIBCPP_INLINE_VISIBILITY
1062_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
1063    return __c11_atomic_fetch_xor(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
1064}
1065template<class _Tp>
1066_LIBCPP_INLINE_VISIBILITY
1067_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
1068    return __c11_atomic_fetch_xor(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
1069}
1070
1071#endif // _LIBCPP_HAS_GCC_ATOMIC_IMP, _LIBCPP_HAS_C_ATOMIC_IMP
1072
1073template <class _Tp>
1074_LIBCPP_INLINE_VISIBILITY
1075_Tp kill_dependency(_Tp __y) _NOEXCEPT
1076{
1077    return __y;
1078}
1079
1080#if defined(__CLANG_ATOMIC_BOOL_LOCK_FREE)
1081# define ATOMIC_BOOL_LOCK_FREE      __CLANG_ATOMIC_BOOL_LOCK_FREE
1082# define ATOMIC_CHAR_LOCK_FREE      __CLANG_ATOMIC_CHAR_LOCK_FREE
1083#ifndef _LIBCPP_HAS_NO_CHAR8_T
1084# define ATOMIC_CHAR8_T_LOCK_FREE   __CLANG_ATOMIC_CHAR8_T_LOCK_FREE
1085#endif
1086# define ATOMIC_CHAR16_T_LOCK_FREE  __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
1087# define ATOMIC_CHAR32_T_LOCK_FREE  __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
1088# define ATOMIC_WCHAR_T_LOCK_FREE   __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
1089# define ATOMIC_SHORT_LOCK_FREE     __CLANG_ATOMIC_SHORT_LOCK_FREE
1090# define ATOMIC_INT_LOCK_FREE       __CLANG_ATOMIC_INT_LOCK_FREE
1091# define ATOMIC_LONG_LOCK_FREE      __CLANG_ATOMIC_LONG_LOCK_FREE
1092# define ATOMIC_LLONG_LOCK_FREE     __CLANG_ATOMIC_LLONG_LOCK_FREE
1093# define ATOMIC_POINTER_LOCK_FREE   __CLANG_ATOMIC_POINTER_LOCK_FREE
1094#elif defined(__GCC_ATOMIC_BOOL_LOCK_FREE)
1095# define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE
1096# define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE
1097#ifndef _LIBCPP_HAS_NO_CHAR8_T
1098# define ATOMIC_CHAR8_T_LOCK_FREE   __GCC_ATOMIC_CHAR8_T_LOCK_FREE
1099#endif
1100# define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE
1101# define ATOMIC_CHAR32_T_LOCK_FREE  __GCC_ATOMIC_CHAR32_T_LOCK_FREE
1102# define ATOMIC_WCHAR_T_LOCK_FREE   __GCC_ATOMIC_WCHAR_T_LOCK_FREE
1103# define ATOMIC_SHORT_LOCK_FREE     __GCC_ATOMIC_SHORT_LOCK_FREE
1104# define ATOMIC_INT_LOCK_FREE       __GCC_ATOMIC_INT_LOCK_FREE
1105# define ATOMIC_LONG_LOCK_FREE      __GCC_ATOMIC_LONG_LOCK_FREE
1106# define ATOMIC_LLONG_LOCK_FREE     __GCC_ATOMIC_LLONG_LOCK_FREE
1107# define ATOMIC_POINTER_LOCK_FREE   __GCC_ATOMIC_POINTER_LOCK_FREE
1108#endif
1109
1110#ifdef _LIBCPP_ATOMIC_ONLY_USE_BUILTINS
1111
1112template<typename _Tp>
1113struct __cxx_atomic_lock_impl {
1114
1115  _LIBCPP_INLINE_VISIBILITY
1116  __cxx_atomic_lock_impl() _NOEXCEPT
1117    : __a_value(), __a_lock(0) {}
1118  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR explicit
1119  __cxx_atomic_lock_impl(_Tp value) _NOEXCEPT
1120    : __a_value(value), __a_lock(0) {}
1121
1122  _Tp __a_value;
1123  mutable __cxx_atomic_base_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_lock;
1124
1125  _LIBCPP_INLINE_VISIBILITY void __lock() const volatile {
1126    while(1 == __cxx_atomic_exchange(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(true), memory_order_acquire))
1127        /*spin*/;
1128  }
1129  _LIBCPP_INLINE_VISIBILITY void __lock() const {
1130    while(1 == __cxx_atomic_exchange(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(true), memory_order_acquire))
1131        /*spin*/;
1132  }
1133  _LIBCPP_INLINE_VISIBILITY void __unlock() const volatile {
1134    __cxx_atomic_store(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(false), memory_order_release);
1135  }
1136  _LIBCPP_INLINE_VISIBILITY void __unlock() const {
1137    __cxx_atomic_store(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(false), memory_order_release);
1138  }
1139  _LIBCPP_INLINE_VISIBILITY _Tp __read() const volatile {
1140    __lock();
1141    _Tp __old;
1142    __cxx_atomic_assign_volatile(__old, __a_value);
1143    __unlock();
1144    return __old;
1145  }
1146  _LIBCPP_INLINE_VISIBILITY _Tp __read() const {
1147    __lock();
1148    _Tp __old = __a_value;
1149    __unlock();
1150    return __old;
1151  }
1152};
1153
1154template <typename _Tp>
1155_LIBCPP_INLINE_VISIBILITY
1156void __cxx_atomic_init(volatile __cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val) {
1157  __cxx_atomic_assign_volatile(__a->__a_value, __val);
1158}
1159template <typename _Tp>
1160_LIBCPP_INLINE_VISIBILITY
1161void __cxx_atomic_init(__cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val) {
1162  __a->__a_value = __val;
1163}
1164
1165template <typename _Tp>
1166_LIBCPP_INLINE_VISIBILITY
1167void __cxx_atomic_store(volatile __cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val, memory_order) {
1168  __a->__lock();
1169  __cxx_atomic_assign_volatile(__a->__a_value, __val);
1170  __a->__unlock();
1171}
1172template <typename _Tp>
1173_LIBCPP_INLINE_VISIBILITY
1174void __cxx_atomic_store(__cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val, memory_order) {
1175  __a->__lock();
1176  __a->__a_value = __val;
1177  __a->__unlock();
1178}
1179
1180template <typename _Tp>
1181_LIBCPP_INLINE_VISIBILITY
1182_Tp __cxx_atomic_load(const volatile __cxx_atomic_lock_impl<_Tp>* __a, memory_order) {
1183  return __a->__read();
1184}
1185template <typename _Tp>
1186_LIBCPP_INLINE_VISIBILITY
1187_Tp __cxx_atomic_load(const __cxx_atomic_lock_impl<_Tp>* __a, memory_order) {
1188  return __a->__read();
1189}
1190
1191template <typename _Tp>
1192_LIBCPP_INLINE_VISIBILITY
1193_Tp __cxx_atomic_exchange(volatile __cxx_atomic_lock_impl<_Tp>* __a, _Tp __value, memory_order) {
1194  __a->__lock();
1195  _Tp __old;
1196  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1197  __cxx_atomic_assign_volatile(__a->__a_value, __value);
1198  __a->__unlock();
1199  return __old;
1200}
1201template <typename _Tp>
1202_LIBCPP_INLINE_VISIBILITY
1203_Tp __cxx_atomic_exchange(__cxx_atomic_lock_impl<_Tp>* __a, _Tp __value, memory_order) {
1204  __a->__lock();
1205  _Tp __old = __a->__a_value;
1206  __a->__a_value = __value;
1207  __a->__unlock();
1208  return __old;
1209}
1210
1211template <typename _Tp>
1212_LIBCPP_INLINE_VISIBILITY
1213bool __cxx_atomic_compare_exchange_strong(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1214                                          _Tp* __expected, _Tp __value, memory_order, memory_order) {
1215  _Tp __temp;
1216  __a->__lock();
1217  __cxx_atomic_assign_volatile(__temp, __a->__a_value);
1218  bool __ret = (_VSTD::memcmp(&__temp, __expected, sizeof(_Tp)) == 0);
1219  if(__ret)
1220    __cxx_atomic_assign_volatile(__a->__a_value, __value);
1221  else
1222    __cxx_atomic_assign_volatile(*__expected, __a->__a_value);
1223  __a->__unlock();
1224  return __ret;
1225}
1226template <typename _Tp>
1227_LIBCPP_INLINE_VISIBILITY
1228bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_lock_impl<_Tp>* __a,
1229                                          _Tp* __expected, _Tp __value, memory_order, memory_order) {
1230  __a->__lock();
1231  bool __ret = (_VSTD::memcmp(&__a->__a_value, __expected, sizeof(_Tp)) == 0);
1232  if(__ret)
1233    _VSTD::memcpy(&__a->__a_value, &__value, sizeof(_Tp));
1234  else
1235    _VSTD::memcpy(__expected, &__a->__a_value, sizeof(_Tp));
1236  __a->__unlock();
1237  return __ret;
1238}
1239
1240template <typename _Tp>
1241_LIBCPP_INLINE_VISIBILITY
1242bool __cxx_atomic_compare_exchange_weak(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1243                                        _Tp* __expected, _Tp __value, memory_order, memory_order) {
1244  _Tp __temp;
1245  __a->__lock();
1246  __cxx_atomic_assign_volatile(__temp, __a->__a_value);
1247  bool __ret = (_VSTD::memcmp(&__temp, __expected, sizeof(_Tp)) == 0);
1248  if(__ret)
1249    __cxx_atomic_assign_volatile(__a->__a_value, __value);
1250  else
1251    __cxx_atomic_assign_volatile(*__expected, __a->__a_value);
1252  __a->__unlock();
1253  return __ret;
1254}
1255template <typename _Tp>
1256_LIBCPP_INLINE_VISIBILITY
1257bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_lock_impl<_Tp>* __a,
1258                                        _Tp* __expected, _Tp __value, memory_order, memory_order) {
1259  __a->__lock();
1260  bool __ret = (_VSTD::memcmp(&__a->__a_value, __expected, sizeof(_Tp)) == 0);
1261  if(__ret)
1262    _VSTD::memcpy(&__a->__a_value, &__value, sizeof(_Tp));
1263  else
1264    _VSTD::memcpy(__expected, &__a->__a_value, sizeof(_Tp));
1265  __a->__unlock();
1266  return __ret;
1267}
1268
1269template <typename _Tp, typename _Td>
1270_LIBCPP_INLINE_VISIBILITY
1271_Tp __cxx_atomic_fetch_add(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1272                           _Td __delta, memory_order) {
1273  __a->__lock();
1274  _Tp __old;
1275  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1276  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old + __delta));
1277  __a->__unlock();
1278  return __old;
1279}
1280template <typename _Tp, typename _Td>
1281_LIBCPP_INLINE_VISIBILITY
1282_Tp __cxx_atomic_fetch_add(__cxx_atomic_lock_impl<_Tp>* __a,
1283                           _Td __delta, memory_order) {
1284  __a->__lock();
1285  _Tp __old = __a->__a_value;
1286  __a->__a_value += __delta;
1287  __a->__unlock();
1288  return __old;
1289}
1290
1291template <typename _Tp, typename _Td>
1292_LIBCPP_INLINE_VISIBILITY
1293_Tp* __cxx_atomic_fetch_add(volatile __cxx_atomic_lock_impl<_Tp*>* __a,
1294                           ptrdiff_t __delta, memory_order) {
1295  __a->__lock();
1296  _Tp* __old;
1297  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1298  __cxx_atomic_assign_volatile(__a->__a_value, __old + __delta);
1299  __a->__unlock();
1300  return __old;
1301}
1302template <typename _Tp, typename _Td>
1303_LIBCPP_INLINE_VISIBILITY
1304_Tp* __cxx_atomic_fetch_add(__cxx_atomic_lock_impl<_Tp*>* __a,
1305                           ptrdiff_t __delta, memory_order) {
1306  __a->__lock();
1307  _Tp* __old = __a->__a_value;
1308  __a->__a_value += __delta;
1309  __a->__unlock();
1310  return __old;
1311}
1312
1313template <typename _Tp, typename _Td>
1314_LIBCPP_INLINE_VISIBILITY
1315_Tp __cxx_atomic_fetch_sub(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1316                           _Td __delta, memory_order) {
1317  __a->__lock();
1318  _Tp __old;
1319  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1320  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old - __delta));
1321  __a->__unlock();
1322  return __old;
1323}
1324template <typename _Tp, typename _Td>
1325_LIBCPP_INLINE_VISIBILITY
1326_Tp __cxx_atomic_fetch_sub(__cxx_atomic_lock_impl<_Tp>* __a,
1327                           _Td __delta, memory_order) {
1328  __a->__lock();
1329  _Tp __old = __a->__a_value;
1330  __a->__a_value -= __delta;
1331  __a->__unlock();
1332  return __old;
1333}
1334
1335template <typename _Tp>
1336_LIBCPP_INLINE_VISIBILITY
1337_Tp __cxx_atomic_fetch_and(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1338                           _Tp __pattern, memory_order) {
1339  __a->__lock();
1340  _Tp __old;
1341  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1342  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old & __pattern));
1343  __a->__unlock();
1344  return __old;
1345}
1346template <typename _Tp>
1347_LIBCPP_INLINE_VISIBILITY
1348_Tp __cxx_atomic_fetch_and(__cxx_atomic_lock_impl<_Tp>* __a,
1349                           _Tp __pattern, memory_order) {
1350  __a->__lock();
1351  _Tp __old = __a->__a_value;
1352  __a->__a_value &= __pattern;
1353  __a->__unlock();
1354  return __old;
1355}
1356
1357template <typename _Tp>
1358_LIBCPP_INLINE_VISIBILITY
1359_Tp __cxx_atomic_fetch_or(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1360                          _Tp __pattern, memory_order) {
1361  __a->__lock();
1362  _Tp __old;
1363  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1364  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old | __pattern));
1365  __a->__unlock();
1366  return __old;
1367}
1368template <typename _Tp>
1369_LIBCPP_INLINE_VISIBILITY
1370_Tp __cxx_atomic_fetch_or(__cxx_atomic_lock_impl<_Tp>* __a,
1371                          _Tp __pattern, memory_order) {
1372  __a->__lock();
1373  _Tp __old = __a->__a_value;
1374  __a->__a_value |= __pattern;
1375  __a->__unlock();
1376  return __old;
1377}
1378
1379template <typename _Tp>
1380_LIBCPP_INLINE_VISIBILITY
1381_Tp __cxx_atomic_fetch_xor(volatile __cxx_atomic_lock_impl<_Tp>* __a,
1382                           _Tp __pattern, memory_order) {
1383  __a->__lock();
1384  _Tp __old;
1385  __cxx_atomic_assign_volatile(__old, __a->__a_value);
1386  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old ^ __pattern));
1387  __a->__unlock();
1388  return __old;
1389}
1390template <typename _Tp>
1391_LIBCPP_INLINE_VISIBILITY
1392_Tp __cxx_atomic_fetch_xor(__cxx_atomic_lock_impl<_Tp>* __a,
1393                           _Tp __pattern, memory_order) {
1394  __a->__lock();
1395  _Tp __old = __a->__a_value;
1396  __a->__a_value ^= __pattern;
1397  __a->__unlock();
1398  return __old;
1399}
1400
1401#ifdef __cpp_lib_atomic_is_always_lock_free
1402
1403template<typename _Tp> struct __cxx_is_always_lock_free {
1404    enum { __value = __atomic_always_lock_free(sizeof(_Tp), 0) }; };
1405
1406#else
1407
1408template<typename _Tp> struct __cxx_is_always_lock_free { enum { __value = false }; };
1409// Implementations must match the C ATOMIC_*_LOCK_FREE macro values.
1410template<> struct __cxx_is_always_lock_free<bool> { enum { __value = 2 == ATOMIC_BOOL_LOCK_FREE }; };
1411template<> struct __cxx_is_always_lock_free<char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
1412template<> struct __cxx_is_always_lock_free<signed char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
1413template<> struct __cxx_is_always_lock_free<unsigned char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
1414#ifndef _LIBCPP_HAS_NO_CHAR8_T
1415template<> struct __cxx_is_always_lock_free<char8_t> { enum { __value = 2 == ATOMIC_CHAR8_T_LOCK_FREE }; };
1416#endif
1417template<> struct __cxx_is_always_lock_free<char16_t> { enum { __value = 2 == ATOMIC_CHAR16_T_LOCK_FREE }; };
1418template<> struct __cxx_is_always_lock_free<char32_t> { enum { __value = 2 == ATOMIC_CHAR32_T_LOCK_FREE }; };
1419#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
1420template<> struct __cxx_is_always_lock_free<wchar_t> { enum { __value = 2 == ATOMIC_WCHAR_T_LOCK_FREE }; };
1421#endif
1422template<> struct __cxx_is_always_lock_free<short> { enum { __value = 2 == ATOMIC_SHORT_LOCK_FREE }; };
1423template<> struct __cxx_is_always_lock_free<unsigned short> { enum { __value = 2 == ATOMIC_SHORT_LOCK_FREE }; };
1424template<> struct __cxx_is_always_lock_free<int> { enum { __value = 2 == ATOMIC_INT_LOCK_FREE }; };
1425template<> struct __cxx_is_always_lock_free<unsigned int> { enum { __value = 2 == ATOMIC_INT_LOCK_FREE }; };
1426template<> struct __cxx_is_always_lock_free<long> { enum { __value = 2 == ATOMIC_LONG_LOCK_FREE }; };
1427template<> struct __cxx_is_always_lock_free<unsigned long> { enum { __value = 2 == ATOMIC_LONG_LOCK_FREE }; };
1428template<> struct __cxx_is_always_lock_free<long long> { enum { __value = 2 == ATOMIC_LLONG_LOCK_FREE }; };
1429template<> struct __cxx_is_always_lock_free<unsigned long long> { enum { __value = 2 == ATOMIC_LLONG_LOCK_FREE }; };
1430template<typename _Tp> struct __cxx_is_always_lock_free<_Tp*> { enum { __value = 2 == ATOMIC_POINTER_LOCK_FREE }; };
1431template<> struct __cxx_is_always_lock_free<std::nullptr_t> { enum { __value = 2 == ATOMIC_POINTER_LOCK_FREE }; };
1432
1433#endif //__cpp_lib_atomic_is_always_lock_free
1434
1435template <typename _Tp,
1436          typename _Base = typename conditional<__cxx_is_always_lock_free<_Tp>::__value,
1437                                                __cxx_atomic_base_impl<_Tp>,
1438                                                __cxx_atomic_lock_impl<_Tp> >::type>
1439#else
1440template <typename _Tp,
1441          typename _Base = __cxx_atomic_base_impl<_Tp> >
1442#endif //_LIBCPP_ATOMIC_ONLY_USE_BUILTINS
1443struct __cxx_atomic_impl : public _Base {
1444    static_assert(is_trivially_copyable<_Tp>::value,
1445      "std::atomic<T> requires that 'T' be a trivially copyable type");
1446
1447  _LIBCPP_INLINE_VISIBILITY __cxx_atomic_impl() _NOEXCEPT = default;
1448  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR explicit __cxx_atomic_impl(_Tp value) _NOEXCEPT
1449    : _Base(value) {}
1450};
1451
1452#if defined(__linux__) || (defined(__FreeBSD__) && defined(__mips__))
1453    using __cxx_contention_t = int32_t;
1454#else
1455    using __cxx_contention_t = int64_t;
1456#endif
1457
1458using __cxx_atomic_contention_t = __cxx_atomic_impl<__cxx_contention_t>;
1459
1460#if defined(_LIBCPP_HAS_NO_THREADS)
1461#   define _LIBCPP_HAS_NO_PLATFORM_WAIT
1462#endif
1463
1464// TODO:
1465// _LIBCPP_HAS_NO_PLATFORM_WAIT is currently a "dead" macro, in the sense that
1466// it is not tied anywhere into the build system or even documented. We should
1467// clean it up because it is technically never defined except when threads are
1468// disabled. We should clean it up in its own changeset in case we break "bad"
1469// users.
1470#ifndef _LIBCPP_HAS_NO_PLATFORM_WAIT
1471
1472_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_one(void const volatile*);
1473_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_all(void const volatile*);
1474_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI __cxx_contention_t __libcpp_atomic_monitor(void const volatile*);
1475_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __libcpp_atomic_wait(void const volatile*, __cxx_contention_t);
1476
1477_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_one(__cxx_atomic_contention_t const volatile*);
1478_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_all(__cxx_atomic_contention_t const volatile*);
1479_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI __cxx_contention_t __libcpp_atomic_monitor(__cxx_atomic_contention_t const volatile*);
1480_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __libcpp_atomic_wait(__cxx_atomic_contention_t const volatile*, __cxx_contention_t);
1481
1482template <class _Atp, class _Fn>
1483struct __libcpp_atomic_wait_backoff_impl {
1484    _Atp* __a;
1485    _Fn __test_fn;
1486    _LIBCPP_AVAILABILITY_SYNC
1487    _LIBCPP_INLINE_VISIBILITY bool operator()(chrono::nanoseconds __elapsed) const
1488    {
1489        if(__elapsed > chrono::microseconds(64))
1490        {
1491            auto const __monitor = __libcpp_atomic_monitor(__a);
1492            if(__test_fn())
1493                return true;
1494            __libcpp_atomic_wait(__a, __monitor);
1495        }
1496        else if(__elapsed > chrono::microseconds(4))
1497            __libcpp_thread_yield();
1498        else
1499            {} // poll
1500        return false;
1501    }
1502};
1503
1504template <class _Atp, class _Fn>
1505_LIBCPP_AVAILABILITY_SYNC
1506_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp* __a, _Fn && __test_fn)
1507{
1508    __libcpp_atomic_wait_backoff_impl<_Atp, typename decay<_Fn>::type> __backoff_fn = {__a, __test_fn};
1509    return __libcpp_thread_poll_with_backoff(__test_fn, __backoff_fn);
1510}
1511
1512#else // _LIBCPP_HAS_NO_PLATFORM_WAIT
1513
1514template <class _Tp>
1515_LIBCPP_INLINE_VISIBILITY void __cxx_atomic_notify_all(__cxx_atomic_impl<_Tp> const volatile*) { }
1516template <class _Tp>
1517_LIBCPP_INLINE_VISIBILITY void __cxx_atomic_notify_one(__cxx_atomic_impl<_Tp> const volatile*) { }
1518template <class _Atp, class _Fn>
1519_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp*, _Fn && __test_fn)
1520{
1521#if defined(_LIBCPP_HAS_NO_THREADS)
1522    using _Policy = __spinning_backoff_policy;
1523#else
1524    using _Policy = __libcpp_timed_backoff_policy;
1525#endif
1526    return __libcpp_thread_poll_with_backoff(__test_fn, _Policy());
1527}
1528
1529#endif // _LIBCPP_HAS_NO_PLATFORM_WAIT
1530
1531template <class _Atp, class _Tp>
1532struct __cxx_atomic_wait_test_fn_impl {
1533    _Atp* __a;
1534    _Tp __val;
1535    memory_order __order;
1536    _LIBCPP_INLINE_VISIBILITY bool operator()() const
1537    {
1538        return !__cxx_nonatomic_compare_equal(__cxx_atomic_load(__a, __order), __val);
1539    }
1540};
1541
1542template <class _Atp, class _Tp>
1543_LIBCPP_AVAILABILITY_SYNC
1544_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp* __a, _Tp const __val, memory_order __order)
1545{
1546    __cxx_atomic_wait_test_fn_impl<_Atp, _Tp> __test_fn = {__a, __val, __order};
1547    return __cxx_atomic_wait(__a, __test_fn);
1548}
1549
1550// general atomic<T>
1551
1552template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value>
1553struct __atomic_base  // false
1554{
1555    mutable __cxx_atomic_impl<_Tp> __a_;
1556
1557#if defined(__cpp_lib_atomic_is_always_lock_free)
1558  static _LIBCPP_CONSTEXPR bool is_always_lock_free = __atomic_always_lock_free(sizeof(__a_), 0);
1559#endif
1560
1561    _LIBCPP_INLINE_VISIBILITY
1562    bool is_lock_free() const volatile _NOEXCEPT
1563        {return __cxx_atomic_is_lock_free(sizeof(_Tp));}
1564    _LIBCPP_INLINE_VISIBILITY
1565    bool is_lock_free() const _NOEXCEPT
1566        {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();}
1567    _LIBCPP_INLINE_VISIBILITY
1568    void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1569      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
1570        {__cxx_atomic_store(&__a_, __d, __m);}
1571    _LIBCPP_INLINE_VISIBILITY
1572    void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1573      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
1574        {__cxx_atomic_store(&__a_, __d, __m);}
1575    _LIBCPP_INLINE_VISIBILITY
1576    _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
1577      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
1578        {return __cxx_atomic_load(&__a_, __m);}
1579    _LIBCPP_INLINE_VISIBILITY
1580    _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
1581      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
1582        {return __cxx_atomic_load(&__a_, __m);}
1583    _LIBCPP_INLINE_VISIBILITY
1584    operator _Tp() const volatile _NOEXCEPT {return load();}
1585    _LIBCPP_INLINE_VISIBILITY
1586    operator _Tp() const _NOEXCEPT          {return load();}
1587    _LIBCPP_INLINE_VISIBILITY
1588    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1589        {return __cxx_atomic_exchange(&__a_, __d, __m);}
1590    _LIBCPP_INLINE_VISIBILITY
1591    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1592        {return __cxx_atomic_exchange(&__a_, __d, __m);}
1593    _LIBCPP_INLINE_VISIBILITY
1594    bool compare_exchange_weak(_Tp& __e, _Tp __d,
1595                               memory_order __s, memory_order __f) volatile _NOEXCEPT
1596      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
1597        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
1598    _LIBCPP_INLINE_VISIBILITY
1599    bool compare_exchange_weak(_Tp& __e, _Tp __d,
1600                               memory_order __s, memory_order __f) _NOEXCEPT
1601      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
1602        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
1603    _LIBCPP_INLINE_VISIBILITY
1604    bool compare_exchange_strong(_Tp& __e, _Tp __d,
1605                                 memory_order __s, memory_order __f) volatile _NOEXCEPT
1606      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
1607        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
1608    _LIBCPP_INLINE_VISIBILITY
1609    bool compare_exchange_strong(_Tp& __e, _Tp __d,
1610                                 memory_order __s, memory_order __f) _NOEXCEPT
1611      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
1612        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
1613    _LIBCPP_INLINE_VISIBILITY
1614    bool compare_exchange_weak(_Tp& __e, _Tp __d,
1615                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1616        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
1617    _LIBCPP_INLINE_VISIBILITY
1618    bool compare_exchange_weak(_Tp& __e, _Tp __d,
1619                               memory_order __m = memory_order_seq_cst) _NOEXCEPT
1620        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
1621    _LIBCPP_INLINE_VISIBILITY
1622    bool compare_exchange_strong(_Tp& __e, _Tp __d,
1623                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1624        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
1625    _LIBCPP_INLINE_VISIBILITY
1626    bool compare_exchange_strong(_Tp& __e, _Tp __d,
1627                                 memory_order __m = memory_order_seq_cst) _NOEXCEPT
1628        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
1629
1630    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
1631        {__cxx_atomic_wait(&__a_, __v, __m);}
1632    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT
1633        {__cxx_atomic_wait(&__a_, __v, __m);}
1634    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_one() volatile _NOEXCEPT
1635        {__cxx_atomic_notify_one(&__a_);}
1636    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_one() _NOEXCEPT
1637        {__cxx_atomic_notify_one(&__a_);}
1638    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_all() volatile _NOEXCEPT
1639        {__cxx_atomic_notify_all(&__a_);}
1640    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_all() _NOEXCEPT
1641        {__cxx_atomic_notify_all(&__a_);}
1642
1643#if _LIBCPP_STD_VER > 17
1644    _LIBCPP_INLINE_VISIBILITY constexpr
1645    __atomic_base() noexcept(is_nothrow_default_constructible_v<_Tp>) : __a_(_Tp()) {}
1646#else
1647    _LIBCPP_INLINE_VISIBILITY
1648    __atomic_base() _NOEXCEPT = default;
1649#endif
1650
1651    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1652    __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {}
1653
1654#ifndef _LIBCPP_CXX03_LANG
1655    __atomic_base(const __atomic_base&) = delete;
1656#else
1657private:
1658    _LIBCPP_INLINE_VISIBILITY
1659    __atomic_base(const __atomic_base&);
1660#endif
1661};
1662
1663#if defined(__cpp_lib_atomic_is_always_lock_free)
1664template <class _Tp, bool __b>
1665_LIBCPP_CONSTEXPR bool __atomic_base<_Tp, __b>::is_always_lock_free;
1666#endif
1667
1668// atomic<Integral>
1669
1670template <class _Tp>
1671struct __atomic_base<_Tp, true>
1672    : public __atomic_base<_Tp, false>
1673{
1674    typedef __atomic_base<_Tp, false> __base;
1675
1676    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1677    __atomic_base() _NOEXCEPT = default;
1678
1679    _LIBCPP_INLINE_VISIBILITY
1680    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}
1681
1682    _LIBCPP_INLINE_VISIBILITY
1683    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1684        {return __cxx_atomic_fetch_add(&this->__a_, __op, __m);}
1685    _LIBCPP_INLINE_VISIBILITY
1686    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1687        {return __cxx_atomic_fetch_add(&this->__a_, __op, __m);}
1688    _LIBCPP_INLINE_VISIBILITY
1689    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1690        {return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);}
1691    _LIBCPP_INLINE_VISIBILITY
1692    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1693        {return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);}
1694    _LIBCPP_INLINE_VISIBILITY
1695    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1696        {return __cxx_atomic_fetch_and(&this->__a_, __op, __m);}
1697    _LIBCPP_INLINE_VISIBILITY
1698    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1699        {return __cxx_atomic_fetch_and(&this->__a_, __op, __m);}
1700    _LIBCPP_INLINE_VISIBILITY
1701    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1702        {return __cxx_atomic_fetch_or(&this->__a_, __op, __m);}
1703    _LIBCPP_INLINE_VISIBILITY
1704    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1705        {return __cxx_atomic_fetch_or(&this->__a_, __op, __m);}
1706    _LIBCPP_INLINE_VISIBILITY
1707    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
1708        {return __cxx_atomic_fetch_xor(&this->__a_, __op, __m);}
1709    _LIBCPP_INLINE_VISIBILITY
1710    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
1711        {return __cxx_atomic_fetch_xor(&this->__a_, __op, __m);}
1712
1713    _LIBCPP_INLINE_VISIBILITY
1714    _Tp operator++(int) volatile _NOEXCEPT      {return fetch_add(_Tp(1));}
1715    _LIBCPP_INLINE_VISIBILITY
1716    _Tp operator++(int) _NOEXCEPT               {return fetch_add(_Tp(1));}
1717    _LIBCPP_INLINE_VISIBILITY
1718    _Tp operator--(int) volatile _NOEXCEPT      {return fetch_sub(_Tp(1));}
1719    _LIBCPP_INLINE_VISIBILITY
1720    _Tp operator--(int) _NOEXCEPT               {return fetch_sub(_Tp(1));}
1721    _LIBCPP_INLINE_VISIBILITY
1722    _Tp operator++() volatile _NOEXCEPT         {return fetch_add(_Tp(1)) + _Tp(1);}
1723    _LIBCPP_INLINE_VISIBILITY
1724    _Tp operator++() _NOEXCEPT                  {return fetch_add(_Tp(1)) + _Tp(1);}
1725    _LIBCPP_INLINE_VISIBILITY
1726    _Tp operator--() volatile _NOEXCEPT         {return fetch_sub(_Tp(1)) - _Tp(1);}
1727    _LIBCPP_INLINE_VISIBILITY
1728    _Tp operator--() _NOEXCEPT                  {return fetch_sub(_Tp(1)) - _Tp(1);}
1729    _LIBCPP_INLINE_VISIBILITY
1730    _Tp operator+=(_Tp __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
1731    _LIBCPP_INLINE_VISIBILITY
1732    _Tp operator+=(_Tp __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
1733    _LIBCPP_INLINE_VISIBILITY
1734    _Tp operator-=(_Tp __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
1735    _LIBCPP_INLINE_VISIBILITY
1736    _Tp operator-=(_Tp __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
1737    _LIBCPP_INLINE_VISIBILITY
1738    _Tp operator&=(_Tp __op) volatile _NOEXCEPT {return fetch_and(__op) & __op;}
1739    _LIBCPP_INLINE_VISIBILITY
1740    _Tp operator&=(_Tp __op) _NOEXCEPT          {return fetch_and(__op) & __op;}
1741    _LIBCPP_INLINE_VISIBILITY
1742    _Tp operator|=(_Tp __op) volatile _NOEXCEPT {return fetch_or(__op) | __op;}
1743    _LIBCPP_INLINE_VISIBILITY
1744    _Tp operator|=(_Tp __op) _NOEXCEPT          {return fetch_or(__op) | __op;}
1745    _LIBCPP_INLINE_VISIBILITY
1746    _Tp operator^=(_Tp __op) volatile _NOEXCEPT {return fetch_xor(__op) ^ __op;}
1747    _LIBCPP_INLINE_VISIBILITY
1748    _Tp operator^=(_Tp __op) _NOEXCEPT          {return fetch_xor(__op) ^ __op;}
1749};
1750
1751// atomic<T>
1752
1753template <class _Tp>
1754struct atomic
1755    : public __atomic_base<_Tp>
1756{
1757    typedef __atomic_base<_Tp> __base;
1758    typedef _Tp value_type;
1759    typedef value_type difference_type;
1760
1761#if _LIBCPP_STD_VER > 17
1762    _LIBCPP_INLINE_VISIBILITY
1763    atomic() = default;
1764#else
1765    _LIBCPP_INLINE_VISIBILITY
1766    atomic() _NOEXCEPT = default;
1767#endif
1768
1769    _LIBCPP_INLINE_VISIBILITY
1770    _LIBCPP_CONSTEXPR atomic(_Tp __d) _NOEXCEPT : __base(__d) {}
1771
1772    _LIBCPP_INLINE_VISIBILITY
1773    _Tp operator=(_Tp __d) volatile _NOEXCEPT
1774        {__base::store(__d); return __d;}
1775    _LIBCPP_INLINE_VISIBILITY
1776    _Tp operator=(_Tp __d) _NOEXCEPT
1777        {__base::store(__d); return __d;}
1778
1779    atomic& operator=(const atomic&) = delete;
1780    atomic& operator=(const atomic&) volatile = delete;
1781};
1782
1783// atomic<T*>
1784
1785template <class _Tp>
1786struct atomic<_Tp*>
1787    : public __atomic_base<_Tp*>
1788{
1789    typedef __atomic_base<_Tp*> __base;
1790    typedef _Tp* value_type;
1791    typedef ptrdiff_t difference_type;
1792
1793    _LIBCPP_INLINE_VISIBILITY
1794    atomic() _NOEXCEPT = default;
1795
1796    _LIBCPP_INLINE_VISIBILITY
1797    _LIBCPP_CONSTEXPR atomic(_Tp* __d) _NOEXCEPT : __base(__d) {}
1798
1799    _LIBCPP_INLINE_VISIBILITY
1800    _Tp* operator=(_Tp* __d) volatile _NOEXCEPT
1801        {__base::store(__d); return __d;}
1802    _LIBCPP_INLINE_VISIBILITY
1803    _Tp* operator=(_Tp* __d) _NOEXCEPT
1804        {__base::store(__d); return __d;}
1805
1806    _LIBCPP_INLINE_VISIBILITY
1807    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
1808        // __atomic_fetch_add accepts function pointers, guard against them.
1809        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
1810        return __cxx_atomic_fetch_add(&this->__a_, __op, __m);
1811    }
1812
1813    _LIBCPP_INLINE_VISIBILITY
1814    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
1815        // __atomic_fetch_add accepts function pointers, guard against them.
1816        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
1817        return __cxx_atomic_fetch_add(&this->__a_, __op, __m);
1818    }
1819
1820    _LIBCPP_INLINE_VISIBILITY
1821    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
1822        // __atomic_fetch_add accepts function pointers, guard against them.
1823        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
1824        return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);
1825    }
1826
1827    _LIBCPP_INLINE_VISIBILITY
1828    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
1829        // __atomic_fetch_add accepts function pointers, guard against them.
1830        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
1831        return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);
1832    }
1833
1834    _LIBCPP_INLINE_VISIBILITY
1835    _Tp* operator++(int) volatile _NOEXCEPT            {return fetch_add(1);}
1836    _LIBCPP_INLINE_VISIBILITY
1837    _Tp* operator++(int) _NOEXCEPT                     {return fetch_add(1);}
1838    _LIBCPP_INLINE_VISIBILITY
1839    _Tp* operator--(int) volatile _NOEXCEPT            {return fetch_sub(1);}
1840    _LIBCPP_INLINE_VISIBILITY
1841    _Tp* operator--(int) _NOEXCEPT                     {return fetch_sub(1);}
1842    _LIBCPP_INLINE_VISIBILITY
1843    _Tp* operator++() volatile _NOEXCEPT               {return fetch_add(1) + 1;}
1844    _LIBCPP_INLINE_VISIBILITY
1845    _Tp* operator++() _NOEXCEPT                        {return fetch_add(1) + 1;}
1846    _LIBCPP_INLINE_VISIBILITY
1847    _Tp* operator--() volatile _NOEXCEPT               {return fetch_sub(1) - 1;}
1848    _LIBCPP_INLINE_VISIBILITY
1849    _Tp* operator--() _NOEXCEPT                        {return fetch_sub(1) - 1;}
1850    _LIBCPP_INLINE_VISIBILITY
1851    _Tp* operator+=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
1852    _LIBCPP_INLINE_VISIBILITY
1853    _Tp* operator+=(ptrdiff_t __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
1854    _LIBCPP_INLINE_VISIBILITY
1855    _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
1856    _LIBCPP_INLINE_VISIBILITY
1857    _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
1858
1859    atomic& operator=(const atomic&) = delete;
1860    atomic& operator=(const atomic&) volatile = delete;
1861};
1862
1863// atomic_is_lock_free
1864
1865template <class _Tp>
1866_LIBCPP_INLINE_VISIBILITY
1867bool
1868atomic_is_lock_free(const volatile atomic<_Tp>* __o) _NOEXCEPT
1869{
1870    return __o->is_lock_free();
1871}
1872
1873template <class _Tp>
1874_LIBCPP_INLINE_VISIBILITY
1875bool
1876atomic_is_lock_free(const atomic<_Tp>* __o) _NOEXCEPT
1877{
1878    return __o->is_lock_free();
1879}
1880
1881// atomic_init
1882
1883template <class _Tp>
1884_LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY
1885void
1886atomic_init(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
1887{
1888    __cxx_atomic_init(&__o->__a_, __d);
1889}
1890
1891template <class _Tp>
1892_LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY
1893void
1894atomic_init(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
1895{
1896    __cxx_atomic_init(&__o->__a_, __d);
1897}
1898
1899// atomic_store
1900
1901template <class _Tp>
1902_LIBCPP_INLINE_VISIBILITY
1903void
1904atomic_store(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
1905{
1906    __o->store(__d);
1907}
1908
1909template <class _Tp>
1910_LIBCPP_INLINE_VISIBILITY
1911void
1912atomic_store(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
1913{
1914    __o->store(__d);
1915}
1916
1917// atomic_store_explicit
1918
1919template <class _Tp>
1920_LIBCPP_INLINE_VISIBILITY
1921void
1922atomic_store_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
1923  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
1924{
1925    __o->store(__d, __m);
1926}
1927
1928template <class _Tp>
1929_LIBCPP_INLINE_VISIBILITY
1930void
1931atomic_store_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
1932  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
1933{
1934    __o->store(__d, __m);
1935}
1936
1937// atomic_load
1938
1939template <class _Tp>
1940_LIBCPP_INLINE_VISIBILITY
1941_Tp
1942atomic_load(const volatile atomic<_Tp>* __o) _NOEXCEPT
1943{
1944    return __o->load();
1945}
1946
1947template <class _Tp>
1948_LIBCPP_INLINE_VISIBILITY
1949_Tp
1950atomic_load(const atomic<_Tp>* __o) _NOEXCEPT
1951{
1952    return __o->load();
1953}
1954
1955// atomic_load_explicit
1956
1957template <class _Tp>
1958_LIBCPP_INLINE_VISIBILITY
1959_Tp
1960atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
1961  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
1962{
1963    return __o->load(__m);
1964}
1965
1966template <class _Tp>
1967_LIBCPP_INLINE_VISIBILITY
1968_Tp
1969atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
1970  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
1971{
1972    return __o->load(__m);
1973}
1974
1975// atomic_exchange
1976
1977template <class _Tp>
1978_LIBCPP_INLINE_VISIBILITY
1979_Tp
1980atomic_exchange(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
1981{
1982    return __o->exchange(__d);
1983}
1984
1985template <class _Tp>
1986_LIBCPP_INLINE_VISIBILITY
1987_Tp
1988atomic_exchange(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
1989{
1990    return __o->exchange(__d);
1991}
1992
1993// atomic_exchange_explicit
1994
1995template <class _Tp>
1996_LIBCPP_INLINE_VISIBILITY
1997_Tp
1998atomic_exchange_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
1999{
2000    return __o->exchange(__d, __m);
2001}
2002
2003template <class _Tp>
2004_LIBCPP_INLINE_VISIBILITY
2005_Tp
2006atomic_exchange_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
2007{
2008    return __o->exchange(__d, __m);
2009}
2010
2011// atomic_compare_exchange_weak
2012
2013template <class _Tp>
2014_LIBCPP_INLINE_VISIBILITY
2015bool
2016atomic_compare_exchange_weak(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
2017{
2018    return __o->compare_exchange_weak(*__e, __d);
2019}
2020
2021template <class _Tp>
2022_LIBCPP_INLINE_VISIBILITY
2023bool
2024atomic_compare_exchange_weak(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
2025{
2026    return __o->compare_exchange_weak(*__e, __d);
2027}
2028
2029// atomic_compare_exchange_strong
2030
2031template <class _Tp>
2032_LIBCPP_INLINE_VISIBILITY
2033bool
2034atomic_compare_exchange_strong(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
2035{
2036    return __o->compare_exchange_strong(*__e, __d);
2037}
2038
2039template <class _Tp>
2040_LIBCPP_INLINE_VISIBILITY
2041bool
2042atomic_compare_exchange_strong(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
2043{
2044    return __o->compare_exchange_strong(*__e, __d);
2045}
2046
2047// atomic_compare_exchange_weak_explicit
2048
2049template <class _Tp>
2050_LIBCPP_INLINE_VISIBILITY
2051bool
2052atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e,
2053                                      typename atomic<_Tp>::value_type __d,
2054                                      memory_order __s, memory_order __f) _NOEXCEPT
2055  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
2056{
2057    return __o->compare_exchange_weak(*__e, __d, __s, __f);
2058}
2059
2060template <class _Tp>
2061_LIBCPP_INLINE_VISIBILITY
2062bool
2063atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d,
2064                                      memory_order __s, memory_order __f) _NOEXCEPT
2065  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
2066{
2067    return __o->compare_exchange_weak(*__e, __d, __s, __f);
2068}
2069
2070// atomic_compare_exchange_strong_explicit
2071
2072template <class _Tp>
2073_LIBCPP_INLINE_VISIBILITY
2074bool
2075atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o,
2076                                        typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d,
2077                                        memory_order __s, memory_order __f) _NOEXCEPT
2078  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
2079{
2080    return __o->compare_exchange_strong(*__e, __d, __s, __f);
2081}
2082
2083template <class _Tp>
2084_LIBCPP_INLINE_VISIBILITY
2085bool
2086atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e,
2087                                        typename atomic<_Tp>::value_type __d,
2088                                        memory_order __s, memory_order __f) _NOEXCEPT
2089  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
2090{
2091    return __o->compare_exchange_strong(*__e, __d, __s, __f);
2092}
2093
2094// atomic_wait
2095
2096template <class _Tp>
2097_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2098void atomic_wait(const volatile atomic<_Tp>* __o,
2099                 typename atomic<_Tp>::value_type __v) _NOEXCEPT
2100{
2101    return __o->wait(__v);
2102}
2103
2104template <class _Tp>
2105_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2106void atomic_wait(const atomic<_Tp>* __o,
2107                 typename atomic<_Tp>::value_type __v) _NOEXCEPT
2108{
2109    return __o->wait(__v);
2110}
2111
2112// atomic_wait_explicit
2113
2114template <class _Tp>
2115_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2116void atomic_wait_explicit(const volatile atomic<_Tp>* __o,
2117                          typename atomic<_Tp>::value_type __v,
2118                          memory_order __m) _NOEXCEPT
2119  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
2120{
2121    return __o->wait(__v, __m);
2122}
2123
2124template <class _Tp>
2125_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2126void atomic_wait_explicit(const atomic<_Tp>* __o,
2127                          typename atomic<_Tp>::value_type __v,
2128                          memory_order __m) _NOEXCEPT
2129  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
2130{
2131    return __o->wait(__v, __m);
2132}
2133
2134// atomic_notify_one
2135
2136template <class _Tp>
2137_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2138void atomic_notify_one(volatile atomic<_Tp>* __o) _NOEXCEPT
2139{
2140    __o->notify_one();
2141}
2142template <class _Tp>
2143_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2144void atomic_notify_one(atomic<_Tp>* __o) _NOEXCEPT
2145{
2146    __o->notify_one();
2147}
2148
2149// atomic_notify_one
2150
2151template <class _Tp>
2152_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2153void atomic_notify_all(volatile atomic<_Tp>* __o) _NOEXCEPT
2154{
2155    __o->notify_all();
2156}
2157template <class _Tp>
2158_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2159void atomic_notify_all(atomic<_Tp>* __o) _NOEXCEPT
2160{
2161    __o->notify_all();
2162}
2163
2164// atomic_fetch_add
2165
2166template <class _Tp>
2167_LIBCPP_INLINE_VISIBILITY
2168_Tp
2169atomic_fetch_add(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
2170{
2171    return __o->fetch_add(__op);
2172}
2173
2174template <class _Tp>
2175_LIBCPP_INLINE_VISIBILITY
2176_Tp
2177atomic_fetch_add(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
2178{
2179    return __o->fetch_add(__op);
2180}
2181
2182// atomic_fetch_add_explicit
2183
2184template <class _Tp>
2185_LIBCPP_INLINE_VISIBILITY
2186_Tp atomic_fetch_add_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
2187{
2188    return __o->fetch_add(__op, __m);
2189}
2190
2191template <class _Tp>
2192_LIBCPP_INLINE_VISIBILITY
2193_Tp atomic_fetch_add_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
2194{
2195    return __o->fetch_add(__op, __m);
2196}
2197
2198// atomic_fetch_sub
2199
2200template <class _Tp>
2201_LIBCPP_INLINE_VISIBILITY
2202_Tp atomic_fetch_sub(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
2203{
2204    return __o->fetch_sub(__op);
2205}
2206
2207template <class _Tp>
2208_LIBCPP_INLINE_VISIBILITY
2209_Tp atomic_fetch_sub(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
2210{
2211    return __o->fetch_sub(__op);
2212}
2213
2214// atomic_fetch_sub_explicit
2215
2216template <class _Tp>
2217_LIBCPP_INLINE_VISIBILITY
2218_Tp atomic_fetch_sub_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
2219{
2220    return __o->fetch_sub(__op, __m);
2221}
2222
2223template <class _Tp>
2224_LIBCPP_INLINE_VISIBILITY
2225_Tp atomic_fetch_sub_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
2226{
2227    return __o->fetch_sub(__op, __m);
2228}
2229
2230// atomic_fetch_and
2231
2232template <class _Tp>
2233_LIBCPP_INLINE_VISIBILITY
2234typename enable_if
2235<
2236    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2237    _Tp
2238>::type
2239atomic_fetch_and(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
2240{
2241    return __o->fetch_and(__op);
2242}
2243
2244template <class _Tp>
2245_LIBCPP_INLINE_VISIBILITY
2246typename enable_if
2247<
2248    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2249    _Tp
2250>::type
2251atomic_fetch_and(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
2252{
2253    return __o->fetch_and(__op);
2254}
2255
2256// atomic_fetch_and_explicit
2257
2258template <class _Tp>
2259_LIBCPP_INLINE_VISIBILITY
2260typename enable_if
2261<
2262    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2263    _Tp
2264>::type
2265atomic_fetch_and_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
2266{
2267    return __o->fetch_and(__op, __m);
2268}
2269
2270template <class _Tp>
2271_LIBCPP_INLINE_VISIBILITY
2272typename enable_if
2273<
2274    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2275    _Tp
2276>::type
2277atomic_fetch_and_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
2278{
2279    return __o->fetch_and(__op, __m);
2280}
2281
2282// atomic_fetch_or
2283
2284template <class _Tp>
2285_LIBCPP_INLINE_VISIBILITY
2286typename enable_if
2287<
2288    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2289    _Tp
2290>::type
2291atomic_fetch_or(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
2292{
2293    return __o->fetch_or(__op);
2294}
2295
2296template <class _Tp>
2297_LIBCPP_INLINE_VISIBILITY
2298typename enable_if
2299<
2300    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2301    _Tp
2302>::type
2303atomic_fetch_or(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
2304{
2305    return __o->fetch_or(__op);
2306}
2307
2308// atomic_fetch_or_explicit
2309
2310template <class _Tp>
2311_LIBCPP_INLINE_VISIBILITY
2312typename enable_if
2313<
2314    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2315    _Tp
2316>::type
2317atomic_fetch_or_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
2318{
2319    return __o->fetch_or(__op, __m);
2320}
2321
2322template <class _Tp>
2323_LIBCPP_INLINE_VISIBILITY
2324typename enable_if
2325<
2326    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2327    _Tp
2328>::type
2329atomic_fetch_or_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
2330{
2331    return __o->fetch_or(__op, __m);
2332}
2333
2334// atomic_fetch_xor
2335
2336template <class _Tp>
2337_LIBCPP_INLINE_VISIBILITY
2338typename enable_if
2339<
2340    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2341    _Tp
2342>::type
2343atomic_fetch_xor(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
2344{
2345    return __o->fetch_xor(__op);
2346}
2347
2348template <class _Tp>
2349_LIBCPP_INLINE_VISIBILITY
2350typename enable_if
2351<
2352    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2353    _Tp
2354>::type
2355atomic_fetch_xor(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
2356{
2357    return __o->fetch_xor(__op);
2358}
2359
2360// atomic_fetch_xor_explicit
2361
2362template <class _Tp>
2363_LIBCPP_INLINE_VISIBILITY
2364typename enable_if
2365<
2366    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2367    _Tp
2368>::type
2369atomic_fetch_xor_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
2370{
2371    return __o->fetch_xor(__op, __m);
2372}
2373
2374template <class _Tp>
2375_LIBCPP_INLINE_VISIBILITY
2376typename enable_if
2377<
2378    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
2379    _Tp
2380>::type
2381atomic_fetch_xor_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
2382{
2383    return __o->fetch_xor(__op, __m);
2384}
2385
2386// flag type and operations
2387
2388typedef struct atomic_flag
2389{
2390    __cxx_atomic_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_;
2391
2392    _LIBCPP_INLINE_VISIBILITY
2393    bool test(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
2394        {return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);}
2395    _LIBCPP_INLINE_VISIBILITY
2396    bool test(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
2397        {return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);}
2398
2399    _LIBCPP_INLINE_VISIBILITY
2400    bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
2401        {return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);}
2402    _LIBCPP_INLINE_VISIBILITY
2403    bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT
2404        {return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);}
2405    _LIBCPP_INLINE_VISIBILITY
2406    void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
2407        {__cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);}
2408    _LIBCPP_INLINE_VISIBILITY
2409    void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT
2410        {__cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);}
2411
2412    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2413    void wait(bool __v, memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
2414        {__cxx_atomic_wait(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(__v), __m);}
2415    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2416    void wait(bool __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT
2417        {__cxx_atomic_wait(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(__v), __m);}
2418    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2419    void notify_one() volatile _NOEXCEPT
2420        {__cxx_atomic_notify_one(&__a_);}
2421    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2422    void notify_one() _NOEXCEPT
2423        {__cxx_atomic_notify_one(&__a_);}
2424    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2425    void notify_all() volatile _NOEXCEPT
2426        {__cxx_atomic_notify_all(&__a_);}
2427    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
2428    void notify_all() _NOEXCEPT
2429        {__cxx_atomic_notify_all(&__a_);}
2430
2431#if _LIBCPP_STD_VER > 17
2432    _LIBCPP_INLINE_VISIBILITY constexpr
2433    atomic_flag() _NOEXCEPT : __a_(false) {}
2434#else
2435    _LIBCPP_INLINE_VISIBILITY
2436    atomic_flag() _NOEXCEPT = default;
2437#endif
2438
2439    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2440    atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {} // EXTENSION
2441
2442#ifndef _LIBCPP_CXX03_LANG
2443    atomic_flag(const atomic_flag&) = delete;
2444    atomic_flag& operator=(const atomic_flag&) = delete;
2445    atomic_flag& operator=(const atomic_flag&) volatile = delete;
2446#else
2447private:
2448    _LIBCPP_INLINE_VISIBILITY
2449    atomic_flag(const atomic_flag&);
2450    _LIBCPP_INLINE_VISIBILITY
2451    atomic_flag& operator=(const atomic_flag&);
2452    _LIBCPP_INLINE_VISIBILITY
2453    atomic_flag& operator=(const atomic_flag&) volatile;
2454#endif
2455} atomic_flag;
2456
2457
2458inline _LIBCPP_INLINE_VISIBILITY
2459bool
2460atomic_flag_test(const volatile atomic_flag* __o) _NOEXCEPT
2461{
2462    return __o->test();
2463}
2464
2465inline _LIBCPP_INLINE_VISIBILITY
2466bool
2467atomic_flag_test(const atomic_flag* __o) _NOEXCEPT
2468{
2469    return __o->test();
2470}
2471
2472inline _LIBCPP_INLINE_VISIBILITY
2473bool
2474atomic_flag_test_explicit(const volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
2475{
2476    return __o->test(__m);
2477}
2478
2479inline _LIBCPP_INLINE_VISIBILITY
2480bool
2481atomic_flag_test_explicit(const atomic_flag* __o, memory_order __m) _NOEXCEPT
2482{
2483    return __o->test(__m);
2484}
2485
2486inline _LIBCPP_INLINE_VISIBILITY
2487bool
2488atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT
2489{
2490    return __o->test_and_set();
2491}
2492
2493inline _LIBCPP_INLINE_VISIBILITY
2494bool
2495atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT
2496{
2497    return __o->test_and_set();
2498}
2499
2500inline _LIBCPP_INLINE_VISIBILITY
2501bool
2502atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
2503{
2504    return __o->test_and_set(__m);
2505}
2506
2507inline _LIBCPP_INLINE_VISIBILITY
2508bool
2509atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
2510{
2511    return __o->test_and_set(__m);
2512}
2513
2514inline _LIBCPP_INLINE_VISIBILITY
2515void
2516atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT
2517{
2518    __o->clear();
2519}
2520
2521inline _LIBCPP_INLINE_VISIBILITY
2522void
2523atomic_flag_clear(atomic_flag* __o) _NOEXCEPT
2524{
2525    __o->clear();
2526}
2527
2528inline _LIBCPP_INLINE_VISIBILITY
2529void
2530atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
2531{
2532    __o->clear(__m);
2533}
2534
2535inline _LIBCPP_INLINE_VISIBILITY
2536void
2537atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
2538{
2539    __o->clear(__m);
2540}
2541
2542inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2543void
2544atomic_flag_wait(const volatile atomic_flag* __o, bool __v) _NOEXCEPT
2545{
2546    __o->wait(__v);
2547}
2548
2549inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2550void
2551atomic_flag_wait(const atomic_flag* __o, bool __v) _NOEXCEPT
2552{
2553    __o->wait(__v);
2554}
2555
2556inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2557void
2558atomic_flag_wait_explicit(const volatile atomic_flag* __o,
2559                          bool __v, memory_order __m) _NOEXCEPT
2560{
2561    __o->wait(__v, __m);
2562}
2563
2564inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2565void
2566atomic_flag_wait_explicit(const atomic_flag* __o,
2567                          bool __v, memory_order __m) _NOEXCEPT
2568{
2569    __o->wait(__v, __m);
2570}
2571
2572inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2573void
2574atomic_flag_notify_one(volatile atomic_flag* __o) _NOEXCEPT
2575{
2576    __o->notify_one();
2577}
2578
2579inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2580void
2581atomic_flag_notify_one(atomic_flag* __o) _NOEXCEPT
2582{
2583    __o->notify_one();
2584}
2585
2586inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2587void
2588atomic_flag_notify_all(volatile atomic_flag* __o) _NOEXCEPT
2589{
2590    __o->notify_all();
2591}
2592
2593inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
2594void
2595atomic_flag_notify_all(atomic_flag* __o) _NOEXCEPT
2596{
2597    __o->notify_all();
2598}
2599
2600// fences
2601
2602inline _LIBCPP_INLINE_VISIBILITY
2603void
2604atomic_thread_fence(memory_order __m) _NOEXCEPT
2605{
2606    __cxx_atomic_thread_fence(__m);
2607}
2608
2609inline _LIBCPP_INLINE_VISIBILITY
2610void
2611atomic_signal_fence(memory_order __m) _NOEXCEPT
2612{
2613    __cxx_atomic_signal_fence(__m);
2614}
2615
2616// Atomics for standard typedef types
2617
2618typedef atomic<bool>               atomic_bool;
2619typedef atomic<char>               atomic_char;
2620typedef atomic<signed char>        atomic_schar;
2621typedef atomic<unsigned char>      atomic_uchar;
2622typedef atomic<short>              atomic_short;
2623typedef atomic<unsigned short>     atomic_ushort;
2624typedef atomic<int>                atomic_int;
2625typedef atomic<unsigned int>       atomic_uint;
2626typedef atomic<long>               atomic_long;
2627typedef atomic<unsigned long>      atomic_ulong;
2628typedef atomic<long long>          atomic_llong;
2629typedef atomic<unsigned long long> atomic_ullong;
2630#ifndef _LIBCPP_HAS_NO_CHAR8_T
2631typedef atomic<char8_t>            atomic_char8_t;
2632#endif
2633typedef atomic<char16_t>           atomic_char16_t;
2634typedef atomic<char32_t>           atomic_char32_t;
2635#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
2636typedef atomic<wchar_t>            atomic_wchar_t;
2637#endif
2638
2639typedef atomic<int_least8_t>   atomic_int_least8_t;
2640typedef atomic<uint_least8_t>  atomic_uint_least8_t;
2641typedef atomic<int_least16_t>  atomic_int_least16_t;
2642typedef atomic<uint_least16_t> atomic_uint_least16_t;
2643typedef atomic<int_least32_t>  atomic_int_least32_t;
2644typedef atomic<uint_least32_t> atomic_uint_least32_t;
2645typedef atomic<int_least64_t>  atomic_int_least64_t;
2646typedef atomic<uint_least64_t> atomic_uint_least64_t;
2647
2648typedef atomic<int_fast8_t>   atomic_int_fast8_t;
2649typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
2650typedef atomic<int_fast16_t>  atomic_int_fast16_t;
2651typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
2652typedef atomic<int_fast32_t>  atomic_int_fast32_t;
2653typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
2654typedef atomic<int_fast64_t>  atomic_int_fast64_t;
2655typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
2656
2657typedef atomic< int8_t>  atomic_int8_t;
2658typedef atomic<uint8_t>  atomic_uint8_t;
2659typedef atomic< int16_t> atomic_int16_t;
2660typedef atomic<uint16_t> atomic_uint16_t;
2661typedef atomic< int32_t> atomic_int32_t;
2662typedef atomic<uint32_t> atomic_uint32_t;
2663typedef atomic< int64_t> atomic_int64_t;
2664typedef atomic<uint64_t> atomic_uint64_t;
2665
2666typedef atomic<intptr_t>  atomic_intptr_t;
2667typedef atomic<uintptr_t> atomic_uintptr_t;
2668typedef atomic<size_t>    atomic_size_t;
2669typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
2670typedef atomic<intmax_t>  atomic_intmax_t;
2671typedef atomic<uintmax_t> atomic_uintmax_t;
2672
2673// atomic_*_lock_free : prefer the contention type most highly, then the largest lock-free type
2674
2675#ifdef __cpp_lib_atomic_is_always_lock_free
2676# define _LIBCPP_CONTENTION_LOCK_FREE __atomic_always_lock_free(sizeof(__cxx_contention_t), 0)
2677#else
2678# define _LIBCPP_CONTENTION_LOCK_FREE false
2679#endif
2680
2681#if ATOMIC_LLONG_LOCK_FREE == 2
2682typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, long long>::type          __libcpp_signed_lock_free;
2683typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned long long>::type __libcpp_unsigned_lock_free;
2684#elif ATOMIC_INT_LOCK_FREE == 2
2685typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, int>::type                __libcpp_signed_lock_free;
2686typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned int>::type       __libcpp_unsigned_lock_free;
2687#elif ATOMIC_SHORT_LOCK_FREE == 2
2688typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, short>::type              __libcpp_signed_lock_free;
2689typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned short>::type     __libcpp_unsigned_lock_free;
2690#elif ATOMIC_CHAR_LOCK_FREE == 2
2691typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, char>::type               __libcpp_signed_lock_free;
2692typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned char>::type      __libcpp_unsigned_lock_free;
2693#else
2694    // No signed/unsigned lock-free types
2695#define _LIBCPP_NO_LOCK_FREE_TYPES
2696#endif
2697
2698#if !defined(_LIBCPP_NO_LOCK_FREE_TYPES)
2699typedef atomic<__libcpp_signed_lock_free> atomic_signed_lock_free;
2700typedef atomic<__libcpp_unsigned_lock_free> atomic_unsigned_lock_free;
2701#endif
2702
2703#define ATOMIC_FLAG_INIT {false}
2704#define ATOMIC_VAR_INIT(__v) {__v}
2705
2706#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
2707# if defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER >= 1400
2708#  pragma clang deprecated(ATOMIC_FLAG_INIT)
2709#  pragma clang deprecated(ATOMIC_VAR_INIT)
2710# endif
2711#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
2712
2713_LIBCPP_END_NAMESPACE_STD
2714
2715#endif // _LIBCPP_ATOMIC
2716