libstdc++
atomic
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1// -*- C++ -*- header.
2
3// Copyright (C) 2008-2023 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file include/atomic
26 * This is a Standard C++ Library header.
27 */
28
29// Based on "C++ Atomic Types and Operations" by Hans Boehm and Lawrence Crowl.
30// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2427.html
31
32#ifndef _GLIBCXX_ATOMIC
33#define _GLIBCXX_ATOMIC 1
34
35#pragma GCC system_header
36
37#if __cplusplus < 201103L
38# include <bits/c++0x_warning.h>
39#else
40
41#include <bits/atomic_base.h>
42
43namespace std _GLIBCXX_VISIBILITY(default)
44{
45_GLIBCXX_BEGIN_NAMESPACE_VERSION
46
47 /**
48 * @addtogroup atomics
49 * @{
50 */
51
52#if __cplusplus >= 201703L
53# define __cpp_lib_atomic_is_always_lock_free 201603L
54#endif
55
56 template<typename _Tp>
57 struct atomic;
58
59 /// atomic<bool>
60 // NB: No operators or fetch-operations for this type.
61 template<>
62 struct atomic<bool>
63 {
64 using value_type = bool;
65
66 private:
67 __atomic_base<bool> _M_base;
68
69 public:
70 atomic() noexcept = default;
71 ~atomic() noexcept = default;
72 atomic(const atomic&) = delete;
73 atomic& operator=(const atomic&) = delete;
74 atomic& operator=(const atomic&) volatile = delete;
75
76 constexpr atomic(bool __i) noexcept : _M_base(__i) { }
77
78 bool
79 operator=(bool __i) noexcept
80 { return _M_base.operator=(__i); }
81
82 bool
83 operator=(bool __i) volatile noexcept
84 { return _M_base.operator=(__i); }
85
86 operator bool() const noexcept
87 { return _M_base.load(); }
88
89 operator bool() const volatile noexcept
90 { return _M_base.load(); }
91
92 bool
93 is_lock_free() const noexcept { return _M_base.is_lock_free(); }
94
95 bool
96 is_lock_free() const volatile noexcept { return _M_base.is_lock_free(); }
97
98#if __cplusplus >= 201703L
99 static constexpr bool is_always_lock_free = ATOMIC_BOOL_LOCK_FREE == 2;
100#endif
101
102 void
103 store(bool __i, memory_order __m = memory_order_seq_cst) noexcept
104 { _M_base.store(__i, __m); }
105
106 void
107 store(bool __i, memory_order __m = memory_order_seq_cst) volatile noexcept
108 { _M_base.store(__i, __m); }
109
110 bool
111 load(memory_order __m = memory_order_seq_cst) const noexcept
112 { return _M_base.load(__m); }
113
114 bool
115 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
116 { return _M_base.load(__m); }
117
118 bool
119 exchange(bool __i, memory_order __m = memory_order_seq_cst) noexcept
120 { return _M_base.exchange(__i, __m); }
121
122 bool
123 exchange(bool __i,
124 memory_order __m = memory_order_seq_cst) volatile noexcept
125 { return _M_base.exchange(__i, __m); }
126
127 bool
128 compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
129 memory_order __m2) noexcept
130 { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
131
132 bool
133 compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
134 memory_order __m2) volatile noexcept
135 { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
136
137 bool
138 compare_exchange_weak(bool& __i1, bool __i2,
139 memory_order __m = memory_order_seq_cst) noexcept
140 { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
141
142 bool
143 compare_exchange_weak(bool& __i1, bool __i2,
144 memory_order __m = memory_order_seq_cst) volatile noexcept
145 { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
146
147 bool
148 compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
149 memory_order __m2) noexcept
150 { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
151
152 bool
153 compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
154 memory_order __m2) volatile noexcept
155 { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
156
157 bool
158 compare_exchange_strong(bool& __i1, bool __i2,
159 memory_order __m = memory_order_seq_cst) noexcept
160 { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
161
162 bool
163 compare_exchange_strong(bool& __i1, bool __i2,
164 memory_order __m = memory_order_seq_cst) volatile noexcept
165 { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
166
167#if __cpp_lib_atomic_wait
168 void
169 wait(bool __old, memory_order __m = memory_order_seq_cst) const noexcept
170 { _M_base.wait(__old, __m); }
171
172 // TODO add const volatile overload
173
174 void
175 notify_one() noexcept
176 { _M_base.notify_one(); }
177
178 void
179 notify_all() noexcept
180 { _M_base.notify_all(); }
181#endif // __cpp_lib_atomic_wait
182 };
183
184/// @cond undocumented
185#if __cpp_lib_atomic_value_initialization
186# define _GLIBCXX20_INIT(I) = I
187#else
188# define _GLIBCXX20_INIT(I)
189#endif
190/// @endcond
191
192 /**
193 * @brief Generic atomic type, primary class template.
194 *
195 * @tparam _Tp Type to be made atomic, must be trivially copyable.
196 */
197 template<typename _Tp>
198 struct atomic
199 {
200 using value_type = _Tp;
201
202 private:
203 // Align 1/2/4/8/16-byte types to at least their size.
204 static constexpr int _S_min_alignment
205 = (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16
206 ? 0 : sizeof(_Tp);
207
208 static constexpr int _S_alignment
209 = _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp);
210
211 alignas(_S_alignment) _Tp _M_i _GLIBCXX20_INIT(_Tp());
212
213 static_assert(__is_trivially_copyable(_Tp),
214 "std::atomic requires a trivially copyable type");
215
216 static_assert(sizeof(_Tp) > 0,
217 "Incomplete or zero-sized types are not supported");
218
219#if __cplusplus > 201703L
220 static_assert(is_copy_constructible_v<_Tp>);
221 static_assert(is_move_constructible_v<_Tp>);
222 static_assert(is_copy_assignable_v<_Tp>);
223 static_assert(is_move_assignable_v<_Tp>);
224#endif
225
226 public:
227 atomic() = default;
228 ~atomic() noexcept = default;
229 atomic(const atomic&) = delete;
230 atomic& operator=(const atomic&) = delete;
231 atomic& operator=(const atomic&) volatile = delete;
232
233 constexpr atomic(_Tp __i) noexcept : _M_i(__i)
234 {
235#if __cplusplus >= 201402L && __has_builtin(__builtin_clear_padding)
236 if _GLIBCXX17_CONSTEXPR (__atomic_impl::__maybe_has_padding<_Tp>())
237 __builtin_clear_padding(std::__addressof(_M_i));
238#endif
239 }
240
241 operator _Tp() const noexcept
242 { return load(); }
243
244 operator _Tp() const volatile noexcept
245 { return load(); }
246
247 _Tp
248 operator=(_Tp __i) noexcept
249 { store(__i); return __i; }
250
251 _Tp
252 operator=(_Tp __i) volatile noexcept
253 { store(__i); return __i; }
254
255 bool
256 is_lock_free() const noexcept
257 {
258 // Produce a fake, minimally aligned pointer.
259 return __atomic_is_lock_free(sizeof(_M_i),
260 reinterpret_cast<void *>(-_S_alignment));
261 }
262
263 bool
264 is_lock_free() const volatile noexcept
265 {
266 // Produce a fake, minimally aligned pointer.
267 return __atomic_is_lock_free(sizeof(_M_i),
268 reinterpret_cast<void *>(-_S_alignment));
269 }
270
271#if __cplusplus >= 201703L
272 static constexpr bool is_always_lock_free
273 = __atomic_always_lock_free(sizeof(_M_i), 0);
274#endif
275
276 void
277 store(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
278 {
279 __atomic_store(std::__addressof(_M_i),
280 __atomic_impl::__clear_padding(__i),
281 int(__m));
282 }
283
284 void
285 store(_Tp __i, memory_order __m = memory_order_seq_cst) volatile noexcept
286 {
287 __atomic_store(std::__addressof(_M_i),
288 __atomic_impl::__clear_padding(__i),
289 int(__m));
290 }
291
292 _Tp
293 load(memory_order __m = memory_order_seq_cst) const noexcept
294 {
295 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
296 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
297 __atomic_load(std::__addressof(_M_i), __ptr, int(__m));
298 return *__ptr;
299 }
300
301 _Tp
302 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
303 {
304 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
305 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
306 __atomic_load(std::__addressof(_M_i), __ptr, int(__m));
307 return *__ptr;
308 }
309
310 _Tp
311 exchange(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
312 {
313 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
314 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
315 __atomic_exchange(std::__addressof(_M_i),
316 __atomic_impl::__clear_padding(__i),
317 __ptr, int(__m));
318 return *__ptr;
319 }
320
321 _Tp
322 exchange(_Tp __i,
323 memory_order __m = memory_order_seq_cst) volatile noexcept
324 {
325 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
326 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
327 __atomic_exchange(std::__addressof(_M_i),
328 __atomic_impl::__clear_padding(__i),
329 __ptr, int(__m));
330 return *__ptr;
331 }
332
333 bool
334 compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
335 memory_order __f) noexcept
336 {
337 return __atomic_impl::__compare_exchange(_M_i, __e, __i, true,
338 __s, __f);
339 }
340
341 bool
342 compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
343 memory_order __f) volatile noexcept
344 {
345 return __atomic_impl::__compare_exchange(_M_i, __e, __i, true,
346 __s, __f);
347 }
348
349 bool
350 compare_exchange_weak(_Tp& __e, _Tp __i,
351 memory_order __m = memory_order_seq_cst) noexcept
352 { return compare_exchange_weak(__e, __i, __m,
353 __cmpexch_failure_order(__m)); }
354
355 bool
356 compare_exchange_weak(_Tp& __e, _Tp __i,
357 memory_order __m = memory_order_seq_cst) volatile noexcept
358 { return compare_exchange_weak(__e, __i, __m,
359 __cmpexch_failure_order(__m)); }
360
361 bool
362 compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
363 memory_order __f) noexcept
364 {
365 return __atomic_impl::__compare_exchange(_M_i, __e, __i, false,
366 __s, __f);
367 }
368
369 bool
370 compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
371 memory_order __f) volatile noexcept
372 {
373 return __atomic_impl::__compare_exchange(_M_i, __e, __i, false,
374 __s, __f);
375 }
376
377 bool
378 compare_exchange_strong(_Tp& __e, _Tp __i,
379 memory_order __m = memory_order_seq_cst) noexcept
380 { return compare_exchange_strong(__e, __i, __m,
381 __cmpexch_failure_order(__m)); }
382
383 bool
384 compare_exchange_strong(_Tp& __e, _Tp __i,
385 memory_order __m = memory_order_seq_cst) volatile noexcept
386 { return compare_exchange_strong(__e, __i, __m,
387 __cmpexch_failure_order(__m)); }
388
389#if __cpp_lib_atomic_wait
390 void
391 wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
392 {
393 std::__atomic_wait_address_v(&_M_i, __old,
394 [__m, this] { return this->load(__m); });
395 }
396
397 // TODO add const volatile overload
398
399 void
400 notify_one() noexcept
401 { std::__atomic_notify_address(&_M_i, false); }
402
403 void
404 notify_all() noexcept
405 { std::__atomic_notify_address(&_M_i, true); }
406#endif // __cpp_lib_atomic_wait
407
408 };
409#undef _GLIBCXX20_INIT
410
411 /// Partial specialization for pointer types.
412 template<typename _Tp>
413 struct atomic<_Tp*>
414 {
415 using value_type = _Tp*;
416 using difference_type = ptrdiff_t;
417
418 typedef _Tp* __pointer_type;
419 typedef __atomic_base<_Tp*> __base_type;
420 __base_type _M_b;
421
422 atomic() noexcept = default;
423 ~atomic() noexcept = default;
424 atomic(const atomic&) = delete;
425 atomic& operator=(const atomic&) = delete;
426 atomic& operator=(const atomic&) volatile = delete;
427
428 constexpr atomic(__pointer_type __p) noexcept : _M_b(__p) { }
429
430 operator __pointer_type() const noexcept
431 { return __pointer_type(_M_b); }
432
433 operator __pointer_type() const volatile noexcept
434 { return __pointer_type(_M_b); }
435
436 __pointer_type
437 operator=(__pointer_type __p) noexcept
438 { return _M_b.operator=(__p); }
439
440 __pointer_type
441 operator=(__pointer_type __p) volatile noexcept
442 { return _M_b.operator=(__p); }
443
444 __pointer_type
445 operator++(int) noexcept
446 {
447#if __cplusplus >= 201703L
448 static_assert( is_object<_Tp>::value, "pointer to object type" );
449#endif
450 return _M_b++;
451 }
452
453 __pointer_type
454 operator++(int) volatile noexcept
455 {
456#if __cplusplus >= 201703L
457 static_assert( is_object<_Tp>::value, "pointer to object type" );
458#endif
459 return _M_b++;
460 }
461
462 __pointer_type
463 operator--(int) noexcept
464 {
465#if __cplusplus >= 201703L
466 static_assert( is_object<_Tp>::value, "pointer to object type" );
467#endif
468 return _M_b--;
469 }
470
471 __pointer_type
472 operator--(int) volatile noexcept
473 {
474#if __cplusplus >= 201703L
475 static_assert( is_object<_Tp>::value, "pointer to object type" );
476#endif
477 return _M_b--;
478 }
479
480 __pointer_type
481 operator++() noexcept
482 {
483#if __cplusplus >= 201703L
484 static_assert( is_object<_Tp>::value, "pointer to object type" );
485#endif
486 return ++_M_b;
487 }
488
489 __pointer_type
490 operator++() volatile noexcept
491 {
492#if __cplusplus >= 201703L
493 static_assert( is_object<_Tp>::value, "pointer to object type" );
494#endif
495 return ++_M_b;
496 }
497
498 __pointer_type
499 operator--() noexcept
500 {
501#if __cplusplus >= 201703L
502 static_assert( is_object<_Tp>::value, "pointer to object type" );
503#endif
504 return --_M_b;
505 }
506
507 __pointer_type
508 operator--() volatile noexcept
509 {
510#if __cplusplus >= 201703L
511 static_assert( is_object<_Tp>::value, "pointer to object type" );
512#endif
513 return --_M_b;
514 }
515
516 __pointer_type
517 operator+=(ptrdiff_t __d) noexcept
518 {
519#if __cplusplus >= 201703L
520 static_assert( is_object<_Tp>::value, "pointer to object type" );
521#endif
522 return _M_b.operator+=(__d);
523 }
524
525 __pointer_type
526 operator+=(ptrdiff_t __d) volatile noexcept
527 {
528#if __cplusplus >= 201703L
529 static_assert( is_object<_Tp>::value, "pointer to object type" );
530#endif
531 return _M_b.operator+=(__d);
532 }
533
534 __pointer_type
535 operator-=(ptrdiff_t __d) noexcept
536 {
537#if __cplusplus >= 201703L
538 static_assert( is_object<_Tp>::value, "pointer to object type" );
539#endif
540 return _M_b.operator-=(__d);
541 }
542
543 __pointer_type
544 operator-=(ptrdiff_t __d) volatile noexcept
545 {
546#if __cplusplus >= 201703L
547 static_assert( is_object<_Tp>::value, "pointer to object type" );
548#endif
549 return _M_b.operator-=(__d);
550 }
551
552 bool
553 is_lock_free() const noexcept
554 { return _M_b.is_lock_free(); }
555
556 bool
557 is_lock_free() const volatile noexcept
558 { return _M_b.is_lock_free(); }
559
560#if __cplusplus >= 201703L
561 static constexpr bool is_always_lock_free
562 = ATOMIC_POINTER_LOCK_FREE == 2;
563#endif
564
565 void
566 store(__pointer_type __p,
567 memory_order __m = memory_order_seq_cst) noexcept
568 { return _M_b.store(__p, __m); }
569
570 void
571 store(__pointer_type __p,
572 memory_order __m = memory_order_seq_cst) volatile noexcept
573 { return _M_b.store(__p, __m); }
574
575 __pointer_type
576 load(memory_order __m = memory_order_seq_cst) const noexcept
577 { return _M_b.load(__m); }
578
579 __pointer_type
580 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
581 { return _M_b.load(__m); }
582
583 __pointer_type
584 exchange(__pointer_type __p,
585 memory_order __m = memory_order_seq_cst) noexcept
586 { return _M_b.exchange(__p, __m); }
587
588 __pointer_type
589 exchange(__pointer_type __p,
590 memory_order __m = memory_order_seq_cst) volatile noexcept
591 { return _M_b.exchange(__p, __m); }
592
593 bool
594 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
595 memory_order __m1, memory_order __m2) noexcept
596 { return _M_b.compare_exchange_weak(__p1, __p2, __m1, __m2); }
597
598 bool
599 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
600 memory_order __m1,
601 memory_order __m2) volatile noexcept
602 { return _M_b.compare_exchange_weak(__p1, __p2, __m1, __m2); }
603
604 bool
605 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
606 memory_order __m = memory_order_seq_cst) noexcept
607 {
608 return compare_exchange_weak(__p1, __p2, __m,
609 __cmpexch_failure_order(__m));
610 }
611
612 bool
613 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
614 memory_order __m = memory_order_seq_cst) volatile noexcept
615 {
616 return compare_exchange_weak(__p1, __p2, __m,
617 __cmpexch_failure_order(__m));
618 }
619
620 bool
621 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
622 memory_order __m1, memory_order __m2) noexcept
623 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
624
625 bool
626 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
627 memory_order __m1,
628 memory_order __m2) volatile noexcept
629 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
630
631 bool
632 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
633 memory_order __m = memory_order_seq_cst) noexcept
634 {
635 return _M_b.compare_exchange_strong(__p1, __p2, __m,
636 __cmpexch_failure_order(__m));
637 }
638
639 bool
640 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
641 memory_order __m = memory_order_seq_cst) volatile noexcept
642 {
643 return _M_b.compare_exchange_strong(__p1, __p2, __m,
644 __cmpexch_failure_order(__m));
645 }
646
647#if __cpp_lib_atomic_wait
648 void
649 wait(__pointer_type __old, memory_order __m = memory_order_seq_cst) const noexcept
650 { _M_b.wait(__old, __m); }
651
652 // TODO add const volatile overload
653
654 void
655 notify_one() noexcept
656 { _M_b.notify_one(); }
657
658 void
659 notify_all() noexcept
660 { _M_b.notify_all(); }
661#endif // __cpp_lib_atomic_wait
662
663 __pointer_type
664 fetch_add(ptrdiff_t __d,
665 memory_order __m = memory_order_seq_cst) noexcept
666 {
667#if __cplusplus >= 201703L
668 static_assert( is_object<_Tp>::value, "pointer to object type" );
669#endif
670 return _M_b.fetch_add(__d, __m);
671 }
672
673 __pointer_type
674 fetch_add(ptrdiff_t __d,
675 memory_order __m = memory_order_seq_cst) volatile noexcept
676 {
677#if __cplusplus >= 201703L
678 static_assert( is_object<_Tp>::value, "pointer to object type" );
679#endif
680 return _M_b.fetch_add(__d, __m);
681 }
682
683 __pointer_type
684 fetch_sub(ptrdiff_t __d,
685 memory_order __m = memory_order_seq_cst) noexcept
686 {
687#if __cplusplus >= 201703L
688 static_assert( is_object<_Tp>::value, "pointer to object type" );
689#endif
690 return _M_b.fetch_sub(__d, __m);
691 }
692
693 __pointer_type
694 fetch_sub(ptrdiff_t __d,
695 memory_order __m = memory_order_seq_cst) volatile noexcept
696 {
697#if __cplusplus >= 201703L
698 static_assert( is_object<_Tp>::value, "pointer to object type" );
699#endif
700 return _M_b.fetch_sub(__d, __m);
701 }
702 };
703
704
705 /// Explicit specialization for char.
706 template<>
707 struct atomic<char> : __atomic_base<char>
708 {
709 typedef char __integral_type;
710 typedef __atomic_base<char> __base_type;
711
712 atomic() noexcept = default;
713 ~atomic() noexcept = default;
714 atomic(const atomic&) = delete;
715 atomic& operator=(const atomic&) = delete;
716 atomic& operator=(const atomic&) volatile = delete;
717
718 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
719
720 using __base_type::operator __integral_type;
721 using __base_type::operator=;
722
723#if __cplusplus >= 201703L
724 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
725#endif
726 };
727
728 /// Explicit specialization for signed char.
729 template<>
730 struct atomic<signed char> : __atomic_base<signed char>
731 {
732 typedef signed char __integral_type;
733 typedef __atomic_base<signed char> __base_type;
734
735 atomic() noexcept= default;
736 ~atomic() noexcept = default;
737 atomic(const atomic&) = delete;
738 atomic& operator=(const atomic&) = delete;
739 atomic& operator=(const atomic&) volatile = delete;
740
741 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
742
743 using __base_type::operator __integral_type;
744 using __base_type::operator=;
745
746#if __cplusplus >= 201703L
747 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
748#endif
749 };
750
751 /// Explicit specialization for unsigned char.
752 template<>
753 struct atomic<unsigned char> : __atomic_base<unsigned char>
754 {
755 typedef unsigned char __integral_type;
756 typedef __atomic_base<unsigned char> __base_type;
757
758 atomic() noexcept= default;
759 ~atomic() noexcept = default;
760 atomic(const atomic&) = delete;
761 atomic& operator=(const atomic&) = delete;
762 atomic& operator=(const atomic&) volatile = delete;
763
764 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
765
766 using __base_type::operator __integral_type;
767 using __base_type::operator=;
768
769#if __cplusplus >= 201703L
770 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
771#endif
772 };
773
774 /// Explicit specialization for short.
775 template<>
776 struct atomic<short> : __atomic_base<short>
777 {
778 typedef short __integral_type;
779 typedef __atomic_base<short> __base_type;
780
781 atomic() noexcept = default;
782 ~atomic() noexcept = default;
783 atomic(const atomic&) = delete;
784 atomic& operator=(const atomic&) = delete;
785 atomic& operator=(const atomic&) volatile = delete;
786
787 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
788
789 using __base_type::operator __integral_type;
790 using __base_type::operator=;
791
792#if __cplusplus >= 201703L
793 static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
794#endif
795 };
796
797 /// Explicit specialization for unsigned short.
798 template<>
799 struct atomic<unsigned short> : __atomic_base<unsigned short>
800 {
801 typedef unsigned short __integral_type;
802 typedef __atomic_base<unsigned short> __base_type;
803
804 atomic() noexcept = default;
805 ~atomic() noexcept = default;
806 atomic(const atomic&) = delete;
807 atomic& operator=(const atomic&) = delete;
808 atomic& operator=(const atomic&) volatile = delete;
809
810 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
811
812 using __base_type::operator __integral_type;
813 using __base_type::operator=;
814
815#if __cplusplus >= 201703L
816 static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
817#endif
818 };
819
820 /// Explicit specialization for int.
821 template<>
822 struct atomic<int> : __atomic_base<int>
823 {
824 typedef int __integral_type;
825 typedef __atomic_base<int> __base_type;
826
827 atomic() noexcept = default;
828 ~atomic() noexcept = default;
829 atomic(const atomic&) = delete;
830 atomic& operator=(const atomic&) = delete;
831 atomic& operator=(const atomic&) volatile = delete;
832
833 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
834
835 using __base_type::operator __integral_type;
836 using __base_type::operator=;
837
838#if __cplusplus >= 201703L
839 static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
840#endif
841 };
842
843 /// Explicit specialization for unsigned int.
844 template<>
845 struct atomic<unsigned int> : __atomic_base<unsigned int>
846 {
847 typedef unsigned int __integral_type;
848 typedef __atomic_base<unsigned int> __base_type;
849
850 atomic() noexcept = default;
851 ~atomic() noexcept = default;
852 atomic(const atomic&) = delete;
853 atomic& operator=(const atomic&) = delete;
854 atomic& operator=(const atomic&) volatile = delete;
855
856 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
857
858 using __base_type::operator __integral_type;
859 using __base_type::operator=;
860
861#if __cplusplus >= 201703L
862 static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
863#endif
864 };
865
866 /// Explicit specialization for long.
867 template<>
868 struct atomic<long> : __atomic_base<long>
869 {
870 typedef long __integral_type;
871 typedef __atomic_base<long> __base_type;
872
873 atomic() noexcept = default;
874 ~atomic() noexcept = default;
875 atomic(const atomic&) = delete;
876 atomic& operator=(const atomic&) = delete;
877 atomic& operator=(const atomic&) volatile = delete;
878
879 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
880
881 using __base_type::operator __integral_type;
882 using __base_type::operator=;
883
884#if __cplusplus >= 201703L
885 static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
886#endif
887 };
888
889 /// Explicit specialization for unsigned long.
890 template<>
891 struct atomic<unsigned long> : __atomic_base<unsigned long>
892 {
893 typedef unsigned long __integral_type;
894 typedef __atomic_base<unsigned long> __base_type;
895
896 atomic() noexcept = default;
897 ~atomic() noexcept = default;
898 atomic(const atomic&) = delete;
899 atomic& operator=(const atomic&) = delete;
900 atomic& operator=(const atomic&) volatile = delete;
901
902 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
903
904 using __base_type::operator __integral_type;
905 using __base_type::operator=;
906
907#if __cplusplus >= 201703L
908 static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
909#endif
910 };
911
912 /// Explicit specialization for long long.
913 template<>
914 struct atomic<long long> : __atomic_base<long long>
915 {
916 typedef long long __integral_type;
917 typedef __atomic_base<long long> __base_type;
918
919 atomic() noexcept = default;
920 ~atomic() noexcept = default;
921 atomic(const atomic&) = delete;
922 atomic& operator=(const atomic&) = delete;
923 atomic& operator=(const atomic&) volatile = delete;
924
925 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
926
927 using __base_type::operator __integral_type;
928 using __base_type::operator=;
929
930#if __cplusplus >= 201703L
931 static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
932#endif
933 };
934
935 /// Explicit specialization for unsigned long long.
936 template<>
937 struct atomic<unsigned long long> : __atomic_base<unsigned long long>
938 {
939 typedef unsigned long long __integral_type;
940 typedef __atomic_base<unsigned long long> __base_type;
941
942 atomic() noexcept = default;
943 ~atomic() noexcept = default;
944 atomic(const atomic&) = delete;
945 atomic& operator=(const atomic&) = delete;
946 atomic& operator=(const atomic&) volatile = delete;
947
948 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
949
950 using __base_type::operator __integral_type;
951 using __base_type::operator=;
952
953#if __cplusplus >= 201703L
954 static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
955#endif
956 };
957
958 /// Explicit specialization for wchar_t.
959 template<>
960 struct atomic<wchar_t> : __atomic_base<wchar_t>
961 {
962 typedef wchar_t __integral_type;
963 typedef __atomic_base<wchar_t> __base_type;
964
965 atomic() noexcept = default;
966 ~atomic() noexcept = default;
967 atomic(const atomic&) = delete;
968 atomic& operator=(const atomic&) = delete;
969 atomic& operator=(const atomic&) volatile = delete;
970
971 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
972
973 using __base_type::operator __integral_type;
974 using __base_type::operator=;
975
976#if __cplusplus >= 201703L
977 static constexpr bool is_always_lock_free = ATOMIC_WCHAR_T_LOCK_FREE == 2;
978#endif
979 };
980
981#ifdef _GLIBCXX_USE_CHAR8_T
982 /// Explicit specialization for char8_t.
983 template<>
984 struct atomic<char8_t> : __atomic_base<char8_t>
985 {
986 typedef char8_t __integral_type;
987 typedef __atomic_base<char8_t> __base_type;
988
989 atomic() noexcept = default;
990 ~atomic() noexcept = default;
991 atomic(const atomic&) = delete;
992 atomic& operator=(const atomic&) = delete;
993 atomic& operator=(const atomic&) volatile = delete;
994
995 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
996
997 using __base_type::operator __integral_type;
998 using __base_type::operator=;
999
1000#if __cplusplus > 201402L
1001 static constexpr bool is_always_lock_free
1002 = ATOMIC_CHAR8_T_LOCK_FREE == 2;
1003#endif
1004 };
1005#endif
1006
1007 /// Explicit specialization for char16_t.
1008 template<>
1009 struct atomic<char16_t> : __atomic_base<char16_t>
1010 {
1011 typedef char16_t __integral_type;
1012 typedef __atomic_base<char16_t> __base_type;
1013
1014 atomic() noexcept = default;
1015 ~atomic() noexcept = default;
1016 atomic(const atomic&) = delete;
1017 atomic& operator=(const atomic&) = delete;
1018 atomic& operator=(const atomic&) volatile = delete;
1019
1020 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
1021
1022 using __base_type::operator __integral_type;
1023 using __base_type::operator=;
1024
1025#if __cplusplus >= 201703L
1026 static constexpr bool is_always_lock_free
1027 = ATOMIC_CHAR16_T_LOCK_FREE == 2;
1028#endif
1029 };
1030
1031 /// Explicit specialization for char32_t.
1032 template<>
1033 struct atomic<char32_t> : __atomic_base<char32_t>
1034 {
1035 typedef char32_t __integral_type;
1036 typedef __atomic_base<char32_t> __base_type;
1037
1038 atomic() noexcept = default;
1039 ~atomic() noexcept = default;
1040 atomic(const atomic&) = delete;
1041 atomic& operator=(const atomic&) = delete;
1042 atomic& operator=(const atomic&) volatile = delete;
1043
1044 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
1045
1046 using __base_type::operator __integral_type;
1047 using __base_type::operator=;
1048
1049#if __cplusplus >= 201703L
1050 static constexpr bool is_always_lock_free
1051 = ATOMIC_CHAR32_T_LOCK_FREE == 2;
1052#endif
1053 };
1054
1055
1056 /// atomic_bool
1057 typedef atomic<bool> atomic_bool;
1058
1059 /// atomic_char
1060 typedef atomic<char> atomic_char;
1061
1062 /// atomic_schar
1063 typedef atomic<signed char> atomic_schar;
1064
1065 /// atomic_uchar
1066 typedef atomic<unsigned char> atomic_uchar;
1067
1068 /// atomic_short
1069 typedef atomic<short> atomic_short;
1070
1071 /// atomic_ushort
1072 typedef atomic<unsigned short> atomic_ushort;
1073
1074 /// atomic_int
1075 typedef atomic<int> atomic_int;
1076
1077 /// atomic_uint
1078 typedef atomic<unsigned int> atomic_uint;
1079
1080 /// atomic_long
1081 typedef atomic<long> atomic_long;
1082
1083 /// atomic_ulong
1084 typedef atomic<unsigned long> atomic_ulong;
1085
1086 /// atomic_llong
1087 typedef atomic<long long> atomic_llong;
1088
1089 /// atomic_ullong
1090 typedef atomic<unsigned long long> atomic_ullong;
1091
1092 /// atomic_wchar_t
1093 typedef atomic<wchar_t> atomic_wchar_t;
1094
1095#ifdef _GLIBCXX_USE_CHAR8_T
1096 /// atomic_char8_t
1097 typedef atomic<char8_t> atomic_char8_t;
1098#endif
1099
1100 /// atomic_char16_t
1101 typedef atomic<char16_t> atomic_char16_t;
1102
1103 /// atomic_char32_t
1104 typedef atomic<char32_t> atomic_char32_t;
1105
1106#ifdef _GLIBCXX_USE_C99_STDINT_TR1
1107 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1108 // 2441. Exact-width atomic typedefs should be provided
1109
1110 /// atomic_int8_t
1111 typedef atomic<int8_t> atomic_int8_t;
1112
1113 /// atomic_uint8_t
1114 typedef atomic<uint8_t> atomic_uint8_t;
1115
1116 /// atomic_int16_t
1117 typedef atomic<int16_t> atomic_int16_t;
1118
1119 /// atomic_uint16_t
1120 typedef atomic<uint16_t> atomic_uint16_t;
1121
1122 /// atomic_int32_t
1123 typedef atomic<int32_t> atomic_int32_t;
1124
1125 /// atomic_uint32_t
1126 typedef atomic<uint32_t> atomic_uint32_t;
1127
1128 /// atomic_int64_t
1129 typedef atomic<int64_t> atomic_int64_t;
1130
1131 /// atomic_uint64_t
1132 typedef atomic<uint64_t> atomic_uint64_t;
1133
1134
1135 /// atomic_int_least8_t
1136 typedef atomic<int_least8_t> atomic_int_least8_t;
1137
1138 /// atomic_uint_least8_t
1139 typedef atomic<uint_least8_t> atomic_uint_least8_t;
1140
1141 /// atomic_int_least16_t
1142 typedef atomic<int_least16_t> atomic_int_least16_t;
1143
1144 /// atomic_uint_least16_t
1145 typedef atomic<uint_least16_t> atomic_uint_least16_t;
1146
1147 /// atomic_int_least32_t
1148 typedef atomic<int_least32_t> atomic_int_least32_t;
1149
1150 /// atomic_uint_least32_t
1151 typedef atomic<uint_least32_t> atomic_uint_least32_t;
1152
1153 /// atomic_int_least64_t
1154 typedef atomic<int_least64_t> atomic_int_least64_t;
1155
1156 /// atomic_uint_least64_t
1157 typedef atomic<uint_least64_t> atomic_uint_least64_t;
1158
1159
1160 /// atomic_int_fast8_t
1161 typedef atomic<int_fast8_t> atomic_int_fast8_t;
1162
1163 /// atomic_uint_fast8_t
1164 typedef atomic<uint_fast8_t> atomic_uint_fast8_t;
1165
1166 /// atomic_int_fast16_t
1167 typedef atomic<int_fast16_t> atomic_int_fast16_t;
1168
1169 /// atomic_uint_fast16_t
1170 typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
1171
1172 /// atomic_int_fast32_t
1173 typedef atomic<int_fast32_t> atomic_int_fast32_t;
1174
1175 /// atomic_uint_fast32_t
1176 typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
1177
1178 /// atomic_int_fast64_t
1179 typedef atomic<int_fast64_t> atomic_int_fast64_t;
1180
1181 /// atomic_uint_fast64_t
1182 typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
1183#endif
1184
1185
1186 /// atomic_intptr_t
1187 typedef atomic<intptr_t> atomic_intptr_t;
1188
1189 /// atomic_uintptr_t
1190 typedef atomic<uintptr_t> atomic_uintptr_t;
1191
1192 /// atomic_size_t
1193 typedef atomic<size_t> atomic_size_t;
1194
1195 /// atomic_ptrdiff_t
1196 typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
1197
1198#ifdef _GLIBCXX_USE_C99_STDINT_TR1
1199 /// atomic_intmax_t
1200 typedef atomic<intmax_t> atomic_intmax_t;
1201
1202 /// atomic_uintmax_t
1203 typedef atomic<uintmax_t> atomic_uintmax_t;
1204#endif
1205
1206 // Function definitions, atomic_flag operations.
1207 inline bool
1208 atomic_flag_test_and_set_explicit(atomic_flag* __a,
1209 memory_order __m) noexcept
1210 { return __a->test_and_set(__m); }
1211
1212 inline bool
1213 atomic_flag_test_and_set_explicit(volatile atomic_flag* __a,
1214 memory_order __m) noexcept
1215 { return __a->test_and_set(__m); }
1216
1217#if __cpp_lib_atomic_flag_test
1218 inline bool
1219 atomic_flag_test(const atomic_flag* __a) noexcept
1220 { return __a->test(); }
1221
1222 inline bool
1223 atomic_flag_test(const volatile atomic_flag* __a) noexcept
1224 { return __a->test(); }
1225
1226 inline bool
1227 atomic_flag_test_explicit(const atomic_flag* __a,
1228 memory_order __m) noexcept
1229 { return __a->test(__m); }
1230
1231 inline bool
1232 atomic_flag_test_explicit(const volatile atomic_flag* __a,
1233 memory_order __m) noexcept
1234 { return __a->test(__m); }
1235#endif
1236
1237 inline void
1238 atomic_flag_clear_explicit(atomic_flag* __a, memory_order __m) noexcept
1239 { __a->clear(__m); }
1240
1241 inline void
1242 atomic_flag_clear_explicit(volatile atomic_flag* __a,
1243 memory_order __m) noexcept
1244 { __a->clear(__m); }
1245
1246 inline bool
1247 atomic_flag_test_and_set(atomic_flag* __a) noexcept
1248 { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
1249
1250 inline bool
1251 atomic_flag_test_and_set(volatile atomic_flag* __a) noexcept
1252 { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
1253
1254 inline void
1255 atomic_flag_clear(atomic_flag* __a) noexcept
1256 { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
1257
1258 inline void
1259 atomic_flag_clear(volatile atomic_flag* __a) noexcept
1260 { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
1261
1262#if __cpp_lib_atomic_wait
1263 inline void
1264 atomic_flag_wait(atomic_flag* __a, bool __old) noexcept
1265 { __a->wait(__old); }
1266
1267 inline void
1268 atomic_flag_wait_explicit(atomic_flag* __a, bool __old,
1269 memory_order __m) noexcept
1270 { __a->wait(__old, __m); }
1271
1272 inline void
1273 atomic_flag_notify_one(atomic_flag* __a) noexcept
1274 { __a->notify_one(); }
1275
1276 inline void
1277 atomic_flag_notify_all(atomic_flag* __a) noexcept
1278 { __a->notify_all(); }
1279#endif // __cpp_lib_atomic_wait
1280
1281 /// @cond undocumented
1282 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1283 // 3220. P0558 broke conforming C++14 uses of atomic shared_ptr
1284 template<typename _Tp>
1285 using __atomic_val_t = __type_identity_t<_Tp>;
1286 template<typename _Tp>
1287 using __atomic_diff_t = typename atomic<_Tp>::difference_type;
1288 /// @endcond
1289
1290 // [atomics.nonmembers] Non-member functions.
1291 // Function templates generally applicable to atomic types.
1292 template<typename _ITp>
1293 inline bool
1294 atomic_is_lock_free(const atomic<_ITp>* __a) noexcept
1295 { return __a->is_lock_free(); }
1296
1297 template<typename _ITp>
1298 inline bool
1299 atomic_is_lock_free(const volatile atomic<_ITp>* __a) noexcept
1300 { return __a->is_lock_free(); }
1301
1302 template<typename _ITp>
1303 inline void
1304 atomic_init(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1305 { __a->store(__i, memory_order_relaxed); }
1306
1307 template<typename _ITp>
1308 inline void
1309 atomic_init(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1310 { __a->store(__i, memory_order_relaxed); }
1311
1312 template<typename _ITp>
1313 inline void
1314 atomic_store_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1315 memory_order __m) noexcept
1316 { __a->store(__i, __m); }
1317
1318 template<typename _ITp>
1319 inline void
1320 atomic_store_explicit(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1321 memory_order __m) noexcept
1322 { __a->store(__i, __m); }
1323
1324 template<typename _ITp>
1325 inline _ITp
1326 atomic_load_explicit(const atomic<_ITp>* __a, memory_order __m) noexcept
1327 { return __a->load(__m); }
1328
1329 template<typename _ITp>
1330 inline _ITp
1331 atomic_load_explicit(const volatile atomic<_ITp>* __a,
1332 memory_order __m) noexcept
1333 { return __a->load(__m); }
1334
1335 template<typename _ITp>
1336 inline _ITp
1337 atomic_exchange_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1338 memory_order __m) noexcept
1339 { return __a->exchange(__i, __m); }
1340
1341 template<typename _ITp>
1342 inline _ITp
1343 atomic_exchange_explicit(volatile atomic<_ITp>* __a,
1344 __atomic_val_t<_ITp> __i,
1345 memory_order __m) noexcept
1346 { return __a->exchange(__i, __m); }
1347
1348 template<typename _ITp>
1349 inline bool
1350 atomic_compare_exchange_weak_explicit(atomic<_ITp>* __a,
1351 __atomic_val_t<_ITp>* __i1,
1352 __atomic_val_t<_ITp> __i2,
1353 memory_order __m1,
1354 memory_order __m2) noexcept
1355 { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
1356
1357 template<typename _ITp>
1358 inline bool
1359 atomic_compare_exchange_weak_explicit(volatile atomic<_ITp>* __a,
1360 __atomic_val_t<_ITp>* __i1,
1361 __atomic_val_t<_ITp> __i2,
1362 memory_order __m1,
1363 memory_order __m2) noexcept
1364 { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
1365
1366 template<typename _ITp>
1367 inline bool
1368 atomic_compare_exchange_strong_explicit(atomic<_ITp>* __a,
1369 __atomic_val_t<_ITp>* __i1,
1370 __atomic_val_t<_ITp> __i2,
1371 memory_order __m1,
1372 memory_order __m2) noexcept
1373 { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
1374
1375 template<typename _ITp>
1376 inline bool
1377 atomic_compare_exchange_strong_explicit(volatile atomic<_ITp>* __a,
1378 __atomic_val_t<_ITp>* __i1,
1379 __atomic_val_t<_ITp> __i2,
1380 memory_order __m1,
1381 memory_order __m2) noexcept
1382 { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
1383
1384
1385 template<typename _ITp>
1386 inline void
1387 atomic_store(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1388 { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
1389
1390 template<typename _ITp>
1391 inline void
1392 atomic_store(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1393 { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
1394
1395 template<typename _ITp>
1396 inline _ITp
1397 atomic_load(const atomic<_ITp>* __a) noexcept
1398 { return atomic_load_explicit(__a, memory_order_seq_cst); }
1399
1400 template<typename _ITp>
1401 inline _ITp
1402 atomic_load(const volatile atomic<_ITp>* __a) noexcept
1403 { return atomic_load_explicit(__a, memory_order_seq_cst); }
1404
1405 template<typename _ITp>
1406 inline _ITp
1407 atomic_exchange(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1408 { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
1409
1410 template<typename _ITp>
1411 inline _ITp
1412 atomic_exchange(volatile atomic<_ITp>* __a,
1413 __atomic_val_t<_ITp> __i) noexcept
1414 { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
1415
1416 template<typename _ITp>
1417 inline bool
1418 atomic_compare_exchange_weak(atomic<_ITp>* __a,
1419 __atomic_val_t<_ITp>* __i1,
1420 __atomic_val_t<_ITp> __i2) noexcept
1421 {
1422 return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
1423 memory_order_seq_cst,
1424 memory_order_seq_cst);
1425 }
1426
1427 template<typename _ITp>
1428 inline bool
1429 atomic_compare_exchange_weak(volatile atomic<_ITp>* __a,
1430 __atomic_val_t<_ITp>* __i1,
1431 __atomic_val_t<_ITp> __i2) noexcept
1432 {
1433 return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
1434 memory_order_seq_cst,
1435 memory_order_seq_cst);
1436 }
1437
1438 template<typename _ITp>
1439 inline bool
1440 atomic_compare_exchange_strong(atomic<_ITp>* __a,
1441 __atomic_val_t<_ITp>* __i1,
1442 __atomic_val_t<_ITp> __i2) noexcept
1443 {
1444 return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
1445 memory_order_seq_cst,
1446 memory_order_seq_cst);
1447 }
1448
1449 template<typename _ITp>
1450 inline bool
1451 atomic_compare_exchange_strong(volatile atomic<_ITp>* __a,
1452 __atomic_val_t<_ITp>* __i1,
1453 __atomic_val_t<_ITp> __i2) noexcept
1454 {
1455 return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
1456 memory_order_seq_cst,
1457 memory_order_seq_cst);
1458 }
1459
1460
1461#if __cpp_lib_atomic_wait
1462 template<typename _Tp>
1463 inline void
1464 atomic_wait(const atomic<_Tp>* __a,
1465 typename std::atomic<_Tp>::value_type __old) noexcept
1466 { __a->wait(__old); }
1467
1468 template<typename _Tp>
1469 inline void
1470 atomic_wait_explicit(const atomic<_Tp>* __a,
1471 typename std::atomic<_Tp>::value_type __old,
1472 std::memory_order __m) noexcept
1473 { __a->wait(__old, __m); }
1474
1475 template<typename _Tp>
1476 inline void
1477 atomic_notify_one(atomic<_Tp>* __a) noexcept
1478 { __a->notify_one(); }
1479
1480 template<typename _Tp>
1481 inline void
1482 atomic_notify_all(atomic<_Tp>* __a) noexcept
1483 { __a->notify_all(); }
1484#endif // __cpp_lib_atomic_wait
1485
1486 // Function templates for atomic_integral and atomic_pointer operations only.
1487 // Some operations (and, or, xor) are only available for atomic integrals,
1488 // which is implemented by taking a parameter of type __atomic_base<_ITp>*.
1489
1490 template<typename _ITp>
1491 inline _ITp
1492 atomic_fetch_add_explicit(atomic<_ITp>* __a,
1493 __atomic_diff_t<_ITp> __i,
1494 memory_order __m) noexcept
1495 { return __a->fetch_add(__i, __m); }
1496
1497 template<typename _ITp>
1498 inline _ITp
1499 atomic_fetch_add_explicit(volatile atomic<_ITp>* __a,
1500 __atomic_diff_t<_ITp> __i,
1501 memory_order __m) noexcept
1502 { return __a->fetch_add(__i, __m); }
1503
1504 template<typename _ITp>
1505 inline _ITp
1506 atomic_fetch_sub_explicit(atomic<_ITp>* __a,
1507 __atomic_diff_t<_ITp> __i,
1508 memory_order __m) noexcept
1509 { return __a->fetch_sub(__i, __m); }
1510
1511 template<typename _ITp>
1512 inline _ITp
1513 atomic_fetch_sub_explicit(volatile atomic<_ITp>* __a,
1514 __atomic_diff_t<_ITp> __i,
1515 memory_order __m) noexcept
1516 { return __a->fetch_sub(__i, __m); }
1517
1518 template<typename _ITp>
1519 inline _ITp
1520 atomic_fetch_and_explicit(__atomic_base<_ITp>* __a,
1521 __atomic_val_t<_ITp> __i,
1522 memory_order __m) noexcept
1523 { return __a->fetch_and(__i, __m); }
1524
1525 template<typename _ITp>
1526 inline _ITp
1527 atomic_fetch_and_explicit(volatile __atomic_base<_ITp>* __a,
1528 __atomic_val_t<_ITp> __i,
1529 memory_order __m) noexcept
1530 { return __a->fetch_and(__i, __m); }
1531
1532 template<typename _ITp>
1533 inline _ITp
1534 atomic_fetch_or_explicit(__atomic_base<_ITp>* __a,
1535 __atomic_val_t<_ITp> __i,
1536 memory_order __m) noexcept
1537 { return __a->fetch_or(__i, __m); }
1538
1539 template<typename _ITp>
1540 inline _ITp
1541 atomic_fetch_or_explicit(volatile __atomic_base<_ITp>* __a,
1542 __atomic_val_t<_ITp> __i,
1543 memory_order __m) noexcept
1544 { return __a->fetch_or(__i, __m); }
1545
1546 template<typename _ITp>
1547 inline _ITp
1548 atomic_fetch_xor_explicit(__atomic_base<_ITp>* __a,
1549 __atomic_val_t<_ITp> __i,
1550 memory_order __m) noexcept
1551 { return __a->fetch_xor(__i, __m); }
1552
1553 template<typename _ITp>
1554 inline _ITp
1555 atomic_fetch_xor_explicit(volatile __atomic_base<_ITp>* __a,
1556 __atomic_val_t<_ITp> __i,
1557 memory_order __m) noexcept
1558 { return __a->fetch_xor(__i, __m); }
1559
1560 template<typename _ITp>
1561 inline _ITp
1562 atomic_fetch_add(atomic<_ITp>* __a,
1563 __atomic_diff_t<_ITp> __i) noexcept
1564 { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
1565
1566 template<typename _ITp>
1567 inline _ITp
1568 atomic_fetch_add(volatile atomic<_ITp>* __a,
1569 __atomic_diff_t<_ITp> __i) noexcept
1570 { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
1571
1572 template<typename _ITp>
1573 inline _ITp
1574 atomic_fetch_sub(atomic<_ITp>* __a,
1575 __atomic_diff_t<_ITp> __i) noexcept
1576 { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
1577
1578 template<typename _ITp>
1579 inline _ITp
1580 atomic_fetch_sub(volatile atomic<_ITp>* __a,
1581 __atomic_diff_t<_ITp> __i) noexcept
1582 { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
1583
1584 template<typename _ITp>
1585 inline _ITp
1586 atomic_fetch_and(__atomic_base<_ITp>* __a,
1587 __atomic_val_t<_ITp> __i) noexcept
1588 { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
1589
1590 template<typename _ITp>
1591 inline _ITp
1592 atomic_fetch_and(volatile __atomic_base<_ITp>* __a,
1593 __atomic_val_t<_ITp> __i) noexcept
1594 { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
1595
1596 template<typename _ITp>
1597 inline _ITp
1598 atomic_fetch_or(__atomic_base<_ITp>* __a,
1599 __atomic_val_t<_ITp> __i) noexcept
1600 { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
1601
1602 template<typename _ITp>
1603 inline _ITp
1604 atomic_fetch_or(volatile __atomic_base<_ITp>* __a,
1605 __atomic_val_t<_ITp> __i) noexcept
1606 { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
1607
1608 template<typename _ITp>
1609 inline _ITp
1610 atomic_fetch_xor(__atomic_base<_ITp>* __a,
1611 __atomic_val_t<_ITp> __i) noexcept
1612 { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
1613
1614 template<typename _ITp>
1615 inline _ITp
1616 atomic_fetch_xor(volatile __atomic_base<_ITp>* __a,
1617 __atomic_val_t<_ITp> __i) noexcept
1618 { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
1619
1620#if __cplusplus > 201703L
1621#define __cpp_lib_atomic_float 201711L
1622 template<>
1623 struct atomic<float> : __atomic_float<float>
1624 {
1625 atomic() noexcept = default;
1626
1627 constexpr
1628 atomic(float __fp) noexcept : __atomic_float<float>(__fp)
1629 { }
1630
1631 atomic& operator=(const atomic&) volatile = delete;
1632 atomic& operator=(const atomic&) = delete;
1633
1634 using __atomic_float<float>::operator=;
1635 };
1636
1637 template<>
1638 struct atomic<double> : __atomic_float<double>
1639 {
1640 atomic() noexcept = default;
1641
1642 constexpr
1643 atomic(double __fp) noexcept : __atomic_float<double>(__fp)
1644 { }
1645
1646 atomic& operator=(const atomic&) volatile = delete;
1647 atomic& operator=(const atomic&) = delete;
1648
1649 using __atomic_float<double>::operator=;
1650 };
1651
1652 template<>
1653 struct atomic<long double> : __atomic_float<long double>
1654 {
1655 atomic() noexcept = default;
1656
1657 constexpr
1658 atomic(long double __fp) noexcept : __atomic_float<long double>(__fp)
1659 { }
1660
1661 atomic& operator=(const atomic&) volatile = delete;
1662 atomic& operator=(const atomic&) = delete;
1663
1664 using __atomic_float<long double>::operator=;
1665 };
1666
1667#ifdef __STDCPP_FLOAT16_T__
1668 template<>
1669 struct atomic<_Float16> : __atomic_float<_Float16>
1670 {
1671 atomic() noexcept = default;
1672
1673 constexpr
1674 atomic(_Float16 __fp) noexcept : __atomic_float<_Float16>(__fp)
1675 { }
1676
1677 atomic& operator=(const atomic&) volatile = delete;
1678 atomic& operator=(const atomic&) = delete;
1679
1680 using __atomic_float<_Float16>::operator=;
1681 };
1682#endif
1683
1684#ifdef __STDCPP_FLOAT32_T__
1685 template<>
1686 struct atomic<_Float32> : __atomic_float<_Float32>
1687 {
1688 atomic() noexcept = default;
1689
1690 constexpr
1691 atomic(_Float32 __fp) noexcept : __atomic_float<_Float32>(__fp)
1692 { }
1693
1694 atomic& operator=(const atomic&) volatile = delete;
1695 atomic& operator=(const atomic&) = delete;
1696
1697 using __atomic_float<_Float32>::operator=;
1698 };
1699#endif
1700
1701#ifdef __STDCPP_FLOAT64_T__
1702 template<>
1703 struct atomic<_Float64> : __atomic_float<_Float64>
1704 {
1705 atomic() noexcept = default;
1706
1707 constexpr
1708 atomic(_Float64 __fp) noexcept : __atomic_float<_Float64>(__fp)
1709 { }
1710
1711 atomic& operator=(const atomic&) volatile = delete;
1712 atomic& operator=(const atomic&) = delete;
1713
1714 using __atomic_float<_Float64>::operator=;
1715 };
1716#endif
1717
1718#ifdef __STDCPP_FLOAT128_T__
1719 template<>
1720 struct atomic<_Float128> : __atomic_float<_Float128>
1721 {
1722 atomic() noexcept = default;
1723
1724 constexpr
1725 atomic(_Float128 __fp) noexcept : __atomic_float<_Float128>(__fp)
1726 { }
1727
1728 atomic& operator=(const atomic&) volatile = delete;
1729 atomic& operator=(const atomic&) = delete;
1730
1731 using __atomic_float<_Float128>::operator=;
1732 };
1733#endif
1734
1735#ifdef __STDCPP_BFLOAT16_T__
1736 template<>
1737 struct atomic<__gnu_cxx::__bfloat16_t> : __atomic_float<__gnu_cxx::__bfloat16_t>
1738 {
1739 atomic() noexcept = default;
1740
1741 constexpr
1742 atomic(__gnu_cxx::__bfloat16_t __fp) noexcept : __atomic_float<__gnu_cxx::__bfloat16_t>(__fp)
1743 { }
1744
1745 atomic& operator=(const atomic&) volatile = delete;
1746 atomic& operator=(const atomic&) = delete;
1747
1748 using __atomic_float<__gnu_cxx::__bfloat16_t>::operator=;
1749 };
1750#endif
1751
1752#define __cpp_lib_atomic_ref 201806L
1753
1754 /// Class template to provide atomic operations on a non-atomic variable.
1755 template<typename _Tp>
1756 struct atomic_ref : __atomic_ref<_Tp>
1757 {
1758 explicit
1759 atomic_ref(_Tp& __t) noexcept : __atomic_ref<_Tp>(__t)
1760 { }
1761
1762 atomic_ref& operator=(const atomic_ref&) = delete;
1763
1764 atomic_ref(const atomic_ref&) = default;
1765
1766 using __atomic_ref<_Tp>::operator=;
1767 };
1768
1769#define __cpp_lib_atomic_lock_free_type_aliases 201907L
1770#ifdef _GLIBCXX_HAVE_PLATFORM_WAIT
1771 using atomic_signed_lock_free
1772 = atomic<make_signed_t<__detail::__platform_wait_t>>;
1773 using atomic_unsigned_lock_free
1774 = atomic<make_unsigned_t<__detail::__platform_wait_t>>;
1775#elif ATOMIC_INT_LOCK_FREE || !(ATOMIC_LONG_LOCK_FREE || ATOMIC_CHAR_LOCK_FREE)
1776 using atomic_signed_lock_free = atomic<signed int>;
1777 using atomic_unsigned_lock_free = atomic<unsigned int>;
1778#elif ATOMIC_LONG_LOCK_FREE
1779 using atomic_signed_lock_free = atomic<signed long>;
1780 using atomic_unsigned_lock_free = atomic<unsigned long>;
1781#elif ATOMIC_CHAR_LOCK_FREE
1782 using atomic_signed_lock_free = atomic<signed char>;
1783 using atomic_unsigned_lock_free = atomic<unsigned char>;
1784#endif
1785
1786#endif // C++2a
1787
1788 /// @} group atomics
1789
1790_GLIBCXX_END_NAMESPACE_VERSION
1791} // namespace
1792
1793#endif // C++11
1794
1795#endif // _GLIBCXX_ATOMIC