1// -*- C++ -*- header.
2
3// Copyright (C) 2008-2021 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 201603
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() const noexcept
176 { _M_base.notify_one(); }
177
178 void
179 notify_all() const noexcept
180 { _M_base.notify_all(); }
181#endif // __cpp_lib_atomic_wait
182 };
183
184#if __cplusplus <= 201703L
185# define _GLIBCXX20_INIT(I)
186#else
187# define _GLIBCXX20_INIT(I) = I
188#endif
189
190 /**
191 * @brief Generic atomic type, primary class template.
192 *
193 * @tparam _Tp Type to be made atomic, must be trivially copyable.
194 */
195 template<typename _Tp>
196 struct atomic
197 {
198 using value_type = _Tp;
199
200 private:
201 // Align 1/2/4/8/16-byte types to at least their size.
202 static constexpr int _S_min_alignment
203 = (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16
204 ? 0 : sizeof(_Tp);
205
206 static constexpr int _S_alignment
207 = _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp);
208
209 alignas(_S_alignment) _Tp _M_i _GLIBCXX20_INIT(_Tp());
210
211 static_assert(__is_trivially_copyable(_Tp),
212 "std::atomic requires a trivially copyable type");
213
214 static_assert(sizeof(_Tp) > 0,
215 "Incomplete or zero-sized types are not supported");
216
217#if __cplusplus > 201703L
218 static_assert(is_copy_constructible_v<_Tp>);
219 static_assert(is_move_constructible_v<_Tp>);
220 static_assert(is_copy_assignable_v<_Tp>);
221 static_assert(is_move_assignable_v<_Tp>);
222#endif
223
224 public:
225 atomic() = default;
226 ~atomic() noexcept = default;
227 atomic(const atomic&) = delete;
228 atomic& operator=(const atomic&) = delete;
229 atomic& operator=(const atomic&) volatile = delete;
230
231 constexpr atomic(_Tp __i) noexcept : _M_i(__i) { }
232
233 operator _Tp() const noexcept
234 { return load(); }
235
236 operator _Tp() const volatile noexcept
237 { return load(); }
238
239 _Tp
240 operator=(_Tp __i) noexcept
241 { store(__i); return __i; }
242
243 _Tp
244 operator=(_Tp __i) volatile noexcept
245 { store(__i); return __i; }
246
247 bool
248 is_lock_free() const noexcept
249 {
250 // Produce a fake, minimally aligned pointer.
251 return __atomic_is_lock_free(sizeof(_M_i),
252 reinterpret_cast<void *>(-_S_alignment));
253 }
254
255 bool
256 is_lock_free() const volatile 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#if __cplusplus >= 201703L
264 static constexpr bool is_always_lock_free
265 = __atomic_always_lock_free(sizeof(_M_i), 0);
266#endif
267
268 void
269 store(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
270 {
271 __atomic_store(std::__addressof(_M_i), std::__addressof(__i), int(__m));
272 }
273
274 void
275 store(_Tp __i, memory_order __m = memory_order_seq_cst) volatile noexcept
276 {
277 __atomic_store(std::__addressof(_M_i), std::__addressof(__i), int(__m));
278 }
279
280 _Tp
281 load(memory_order __m = memory_order_seq_cst) const noexcept
282 {
283 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
284 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
285 __atomic_load(std::__addressof(_M_i), __ptr, int(__m));
286 return *__ptr;
287 }
288
289 _Tp
290 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
291 {
292 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
293 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
294 __atomic_load(std::__addressof(_M_i), __ptr, int(__m));
295 return *__ptr;
296 }
297
298 _Tp
299 exchange(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
300 {
301 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
302 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
303 __atomic_exchange(std::__addressof(_M_i), std::__addressof(__i),
304 __ptr, int(__m));
305 return *__ptr;
306 }
307
308 _Tp
309 exchange(_Tp __i,
310 memory_order __m = memory_order_seq_cst) volatile noexcept
311 {
312 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
313 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
314 __atomic_exchange(std::__addressof(_M_i), std::__addressof(__i),
315 __ptr, int(__m));
316 return *__ptr;
317 }
318
319 bool
320 compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
321 memory_order __f) noexcept
322 {
323 return __atomic_compare_exchange(std::__addressof(_M_i),
324 std::__addressof(__e),
325 std::__addressof(__i),
326 true, int(__s), int(__f));
327 }
328
329 bool
330 compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
331 memory_order __f) volatile noexcept
332 {
333 return __atomic_compare_exchange(std::__addressof(_M_i),
334 std::__addressof(__e),
335 std::__addressof(__i),
336 true, int(__s), int(__f));
337 }
338
339 bool
340 compare_exchange_weak(_Tp& __e, _Tp __i,
341 memory_order __m = memory_order_seq_cst) noexcept
342 { return compare_exchange_weak(__e, __i, __m,
343 __cmpexch_failure_order(__m)); }
344
345 bool
346 compare_exchange_weak(_Tp& __e, _Tp __i,
347 memory_order __m = memory_order_seq_cst) volatile noexcept
348 { return compare_exchange_weak(__e, __i, __m,
349 __cmpexch_failure_order(__m)); }
350
351 bool
352 compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
353 memory_order __f) noexcept
354 {
355 return __atomic_compare_exchange(std::__addressof(_M_i),
356 std::__addressof(__e),
357 std::__addressof(__i),
358 false, int(__s), int(__f));
359 }
360
361 bool
362 compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
363 memory_order __f) volatile noexcept
364 {
365 return __atomic_compare_exchange(std::__addressof(_M_i),
366 std::__addressof(__e),
367 std::__addressof(__i),
368 false, int(__s), int(__f));
369 }
370
371 bool
372 compare_exchange_strong(_Tp& __e, _Tp __i,
373 memory_order __m = memory_order_seq_cst) noexcept
374 { return compare_exchange_strong(__e, __i, __m,
375 __cmpexch_failure_order(__m)); }
376
377 bool
378 compare_exchange_strong(_Tp& __e, _Tp __i,
379 memory_order __m = memory_order_seq_cst) volatile noexcept
380 { return compare_exchange_strong(__e, __i, __m,
381 __cmpexch_failure_order(__m)); }
382
383#if __cpp_lib_atomic_wait
384 void
385 wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
386 {
387 std::__atomic_wait_address_v(&_M_i, __old,
388 [__m, this] { return this->load(__m); });
389 }
390
391 // TODO add const volatile overload
392
393 void
394 notify_one() const noexcept
395 { std::__atomic_notify_address(&_M_i, false); }
396
397 void
398 notify_all() const noexcept
399 { std::__atomic_notify_address(&_M_i, true); }
400#endif // __cpp_lib_atomic_wait
401
402 };
403#undef _GLIBCXX20_INIT
404
405 /// Partial specialization for pointer types.
406 template<typename _Tp>
407 struct atomic<_Tp*>
408 {
409 using value_type = _Tp*;
410 using difference_type = ptrdiff_t;
411
412 typedef _Tp* __pointer_type;
413 typedef __atomic_base<_Tp*> __base_type;
414 __base_type _M_b;
415
416 atomic() noexcept = default;
417 ~atomic() noexcept = default;
418 atomic(const atomic&) = delete;
419 atomic& operator=(const atomic&) = delete;
420 atomic& operator=(const atomic&) volatile = delete;
421
422 constexpr atomic(__pointer_type __p) noexcept : _M_b(__p) { }
423
424 operator __pointer_type() const noexcept
425 { return __pointer_type(_M_b); }
426
427 operator __pointer_type() const volatile noexcept
428 { return __pointer_type(_M_b); }
429
430 __pointer_type
431 operator=(__pointer_type __p) noexcept
432 { return _M_b.operator=(__p); }
433
434 __pointer_type
435 operator=(__pointer_type __p) volatile noexcept
436 { return _M_b.operator=(__p); }
437
438 __pointer_type
439 operator++(int) noexcept
440 {
441#if __cplusplus >= 201703L
442 static_assert( is_object<_Tp>::value, "pointer to object type" );
443#endif
444 return _M_b++;
445 }
446
447 __pointer_type
448 operator++(int) volatile noexcept
449 {
450#if __cplusplus >= 201703L
451 static_assert( is_object<_Tp>::value, "pointer to object type" );
452#endif
453 return _M_b++;
454 }
455
456 __pointer_type
457 operator--(int) noexcept
458 {
459#if __cplusplus >= 201703L
460 static_assert( is_object<_Tp>::value, "pointer to object type" );
461#endif
462 return _M_b--;
463 }
464
465 __pointer_type
466 operator--(int) volatile noexcept
467 {
468#if __cplusplus >= 201703L
469 static_assert( is_object<_Tp>::value, "pointer to object type" );
470#endif
471 return _M_b--;
472 }
473
474 __pointer_type
475 operator++() noexcept
476 {
477#if __cplusplus >= 201703L
478 static_assert( is_object<_Tp>::value, "pointer to object type" );
479#endif
480 return ++_M_b;
481 }
482
483 __pointer_type
484 operator++() volatile noexcept
485 {
486#if __cplusplus >= 201703L
487 static_assert( is_object<_Tp>::value, "pointer to object type" );
488#endif
489 return ++_M_b;
490 }
491
492 __pointer_type
493 operator--() noexcept
494 {
495#if __cplusplus >= 201703L
496 static_assert( is_object<_Tp>::value, "pointer to object type" );
497#endif
498 return --_M_b;
499 }
500
501 __pointer_type
502 operator--() volatile noexcept
503 {
504#if __cplusplus >= 201703L
505 static_assert( is_object<_Tp>::value, "pointer to object type" );
506#endif
507 return --_M_b;
508 }
509
510 __pointer_type
511 operator+=(ptrdiff_t __d) noexcept
512 {
513#if __cplusplus >= 201703L
514 static_assert( is_object<_Tp>::value, "pointer to object type" );
515#endif
516 return _M_b.operator+=(__d);
517 }
518
519 __pointer_type
520 operator+=(ptrdiff_t __d) volatile noexcept
521 {
522#if __cplusplus >= 201703L
523 static_assert( is_object<_Tp>::value, "pointer to object type" );
524#endif
525 return _M_b.operator+=(__d);
526 }
527
528 __pointer_type
529 operator-=(ptrdiff_t __d) noexcept
530 {
531#if __cplusplus >= 201703L
532 static_assert( is_object<_Tp>::value, "pointer to object type" );
533#endif
534 return _M_b.operator-=(__d);
535 }
536
537 __pointer_type
538 operator-=(ptrdiff_t __d) volatile noexcept
539 {
540#if __cplusplus >= 201703L
541 static_assert( is_object<_Tp>::value, "pointer to object type" );
542#endif
543 return _M_b.operator-=(__d);
544 }
545
546 bool
547 is_lock_free() const noexcept
548 { return _M_b.is_lock_free(); }
549
550 bool
551 is_lock_free() const volatile noexcept
552 { return _M_b.is_lock_free(); }
553
554#if __cplusplus >= 201703L
555 static constexpr bool is_always_lock_free = ATOMIC_POINTER_LOCK_FREE == 2;
556#endif
557
558 void
559 store(__pointer_type __p,
560 memory_order __m = memory_order_seq_cst) noexcept
561 { return _M_b.store(__p, __m); }
562
563 void
564 store(__pointer_type __p,
565 memory_order __m = memory_order_seq_cst) volatile noexcept
566 { return _M_b.store(__p, __m); }
567
568 __pointer_type
569 load(memory_order __m = memory_order_seq_cst) const noexcept
570 { return _M_b.load(__m); }
571
572 __pointer_type
573 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
574 { return _M_b.load(__m); }
575
576 __pointer_type
577 exchange(__pointer_type __p,
578 memory_order __m = memory_order_seq_cst) noexcept
579 { return _M_b.exchange(__p, __m); }
580
581 __pointer_type
582 exchange(__pointer_type __p,
583 memory_order __m = memory_order_seq_cst) volatile noexcept
584 { return _M_b.exchange(__p, __m); }
585
586 bool
587 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
588 memory_order __m1, memory_order __m2) noexcept
589 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
590
591 bool
592 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
593 memory_order __m1,
594 memory_order __m2) volatile noexcept
595 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
596
597 bool
598 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
599 memory_order __m = memory_order_seq_cst) noexcept
600 {
601 return compare_exchange_weak(__p1, __p2, __m,
602 __cmpexch_failure_order(__m));
603 }
604
605 bool
606 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
607 memory_order __m = memory_order_seq_cst) volatile noexcept
608 {
609 return compare_exchange_weak(__p1, __p2, __m,
610 __cmpexch_failure_order(__m));
611 }
612
613 bool
614 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
615 memory_order __m1, memory_order __m2) noexcept
616 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
617
618 bool
619 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
620 memory_order __m1,
621 memory_order __m2) volatile noexcept
622 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
623
624 bool
625 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
626 memory_order __m = memory_order_seq_cst) noexcept
627 {
628 return _M_b.compare_exchange_strong(__p1, __p2, __m,
629 __cmpexch_failure_order(__m));
630 }
631
632 bool
633 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
634 memory_order __m = memory_order_seq_cst) volatile noexcept
635 {
636 return _M_b.compare_exchange_strong(__p1, __p2, __m,
637 __cmpexch_failure_order(__m));
638 }
639
640#if __cpp_lib_atomic_wait
641 void
642 wait(__pointer_type __old, memory_order __m = memory_order_seq_cst) const noexcept
643 { _M_b.wait(__old, __m); }
644
645 // TODO add const volatile overload
646
647 void
648 notify_one() const noexcept
649 { _M_b.notify_one(); }
650
651 void
652 notify_all() const noexcept
653 { _M_b.notify_all(); }
654#endif // __cpp_lib_atomic_wait
655 __pointer_type
656 fetch_add(ptrdiff_t __d,
657 memory_order __m = memory_order_seq_cst) noexcept
658 {
659#if __cplusplus >= 201703L
660 static_assert( is_object<_Tp>::value, "pointer to object type" );
661#endif
662 return _M_b.fetch_add(__d, __m);
663 }
664
665 __pointer_type
666 fetch_add(ptrdiff_t __d,
667 memory_order __m = memory_order_seq_cst) volatile noexcept
668 {
669#if __cplusplus >= 201703L
670 static_assert( is_object<_Tp>::value, "pointer to object type" );
671#endif
672 return _M_b.fetch_add(__d, __m);
673 }
674
675 __pointer_type
676 fetch_sub(ptrdiff_t __d,
677 memory_order __m = memory_order_seq_cst) noexcept
678 {
679#if __cplusplus >= 201703L
680 static_assert( is_object<_Tp>::value, "pointer to object type" );
681#endif
682 return _M_b.fetch_sub(__d, __m);
683 }
684
685 __pointer_type
686 fetch_sub(ptrdiff_t __d,
687 memory_order __m = memory_order_seq_cst) volatile noexcept
688 {
689#if __cplusplus >= 201703L
690 static_assert( is_object<_Tp>::value, "pointer to object type" );
691#endif
692 return _M_b.fetch_sub(__d, __m);
693 }
694 };
695
696
697 /// Explicit specialization for char.
698 template<>
699 struct atomic<char> : __atomic_base<char>
700 {
701 typedef char __integral_type;
702 typedef __atomic_base<char> __base_type;
703
704 atomic() noexcept = default;
705 ~atomic() noexcept = default;
706 atomic(const atomic&) = delete;
707 atomic& operator=(const atomic&) = delete;
708 atomic& operator=(const atomic&) volatile = delete;
709
710 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
711
712 using __base_type::operator __integral_type;
713 using __base_type::operator=;
714
715#if __cplusplus >= 201703L
716 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
717#endif
718 };
719
720 /// Explicit specialization for signed char.
721 template<>
722 struct atomic<signed char> : __atomic_base<signed char>
723 {
724 typedef signed char __integral_type;
725 typedef __atomic_base<signed char> __base_type;
726
727 atomic() noexcept= default;
728 ~atomic() noexcept = default;
729 atomic(const atomic&) = delete;
730 atomic& operator=(const atomic&) = delete;
731 atomic& operator=(const atomic&) volatile = delete;
732
733 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
734
735 using __base_type::operator __integral_type;
736 using __base_type::operator=;
737
738#if __cplusplus >= 201703L
739 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
740#endif
741 };
742
743 /// Explicit specialization for unsigned char.
744 template<>
745 struct atomic<unsigned char> : __atomic_base<unsigned char>
746 {
747 typedef unsigned char __integral_type;
748 typedef __atomic_base<unsigned char> __base_type;
749
750 atomic() noexcept= default;
751 ~atomic() noexcept = default;
752 atomic(const atomic&) = delete;
753 atomic& operator=(const atomic&) = delete;
754 atomic& operator=(const atomic&) volatile = delete;
755
756 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
757
758 using __base_type::operator __integral_type;
759 using __base_type::operator=;
760
761#if __cplusplus >= 201703L
762 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
763#endif
764 };
765
766 /// Explicit specialization for short.
767 template<>
768 struct atomic<short> : __atomic_base<short>
769 {
770 typedef short __integral_type;
771 typedef __atomic_base<short> __base_type;
772
773 atomic() noexcept = default;
774 ~atomic() noexcept = default;
775 atomic(const atomic&) = delete;
776 atomic& operator=(const atomic&) = delete;
777 atomic& operator=(const atomic&) volatile = delete;
778
779 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
780
781 using __base_type::operator __integral_type;
782 using __base_type::operator=;
783
784#if __cplusplus >= 201703L
785 static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
786#endif
787 };
788
789 /// Explicit specialization for unsigned short.
790 template<>
791 struct atomic<unsigned short> : __atomic_base<unsigned short>
792 {
793 typedef unsigned short __integral_type;
794 typedef __atomic_base<unsigned short> __base_type;
795
796 atomic() noexcept = default;
797 ~atomic() noexcept = default;
798 atomic(const atomic&) = delete;
799 atomic& operator=(const atomic&) = delete;
800 atomic& operator=(const atomic&) volatile = delete;
801
802 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
803
804 using __base_type::operator __integral_type;
805 using __base_type::operator=;
806
807#if __cplusplus >= 201703L
808 static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
809#endif
810 };
811
812 /// Explicit specialization for int.
813 template<>
814 struct atomic<int> : __atomic_base<int>
815 {
816 typedef int __integral_type;
817 typedef __atomic_base<int> __base_type;
818
819 atomic() noexcept = default;
820 ~atomic() noexcept = default;
821 atomic(const atomic&) = delete;
822 atomic& operator=(const atomic&) = delete;
823 atomic& operator=(const atomic&) volatile = delete;
824
825 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
826
827 using __base_type::operator __integral_type;
828 using __base_type::operator=;
829
830#if __cplusplus >= 201703L
831 static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
832#endif
833 };
834
835 /// Explicit specialization for unsigned int.
836 template<>
837 struct atomic<unsigned int> : __atomic_base<unsigned int>
838 {
839 typedef unsigned int __integral_type;
840 typedef __atomic_base<unsigned int> __base_type;
841
842 atomic() noexcept = default;
843 ~atomic() noexcept = default;
844 atomic(const atomic&) = delete;
845 atomic& operator=(const atomic&) = delete;
846 atomic& operator=(const atomic&) volatile = delete;
847
848 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
849
850 using __base_type::operator __integral_type;
851 using __base_type::operator=;
852
853#if __cplusplus >= 201703L
854 static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
855#endif
856 };
857
858 /// Explicit specialization for long.
859 template<>
860 struct atomic<long> : __atomic_base<long>
861 {
862 typedef long __integral_type;
863 typedef __atomic_base<long> __base_type;
864
865 atomic() noexcept = default;
866 ~atomic() noexcept = default;
867 atomic(const atomic&) = delete;
868 atomic& operator=(const atomic&) = delete;
869 atomic& operator=(const atomic&) volatile = delete;
870
871 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
872
873 using __base_type::operator __integral_type;
874 using __base_type::operator=;
875
876#if __cplusplus >= 201703L
877 static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
878#endif
879 };
880
881 /// Explicit specialization for unsigned long.
882 template<>
883 struct atomic<unsigned long> : __atomic_base<unsigned long>
884 {
885 typedef unsigned long __integral_type;
886 typedef __atomic_base<unsigned long> __base_type;
887
888 atomic() noexcept = default;
889 ~atomic() noexcept = default;
890 atomic(const atomic&) = delete;
891 atomic& operator=(const atomic&) = delete;
892 atomic& operator=(const atomic&) volatile = delete;
893
894 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
895
896 using __base_type::operator __integral_type;
897 using __base_type::operator=;
898
899#if __cplusplus >= 201703L
900 static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
901#endif
902 };
903
904 /// Explicit specialization for long long.
905 template<>
906 struct atomic<long long> : __atomic_base<long long>
907 {
908 typedef long long __integral_type;
909 typedef __atomic_base<long long> __base_type;
910
911 atomic() noexcept = default;
912 ~atomic() noexcept = default;
913 atomic(const atomic&) = delete;
914 atomic& operator=(const atomic&) = delete;
915 atomic& operator=(const atomic&) volatile = delete;
916
917 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
918
919 using __base_type::operator __integral_type;
920 using __base_type::operator=;
921
922#if __cplusplus >= 201703L
923 static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
924#endif
925 };
926
927 /// Explicit specialization for unsigned long long.
928 template<>
929 struct atomic<unsigned long long> : __atomic_base<unsigned long long>
930 {
931 typedef unsigned long long __integral_type;
932 typedef __atomic_base<unsigned long long> __base_type;
933
934 atomic() noexcept = default;
935 ~atomic() noexcept = default;
936 atomic(const atomic&) = delete;
937 atomic& operator=(const atomic&) = delete;
938 atomic& operator=(const atomic&) volatile = delete;
939
940 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
941
942 using __base_type::operator __integral_type;
943 using __base_type::operator=;
944
945#if __cplusplus >= 201703L
946 static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
947#endif
948 };
949
950 /// Explicit specialization for wchar_t.
951 template<>
952 struct atomic<wchar_t> : __atomic_base<wchar_t>
953 {
954 typedef wchar_t __integral_type;
955 typedef __atomic_base<wchar_t> __base_type;
956
957 atomic() noexcept = default;
958 ~atomic() noexcept = default;
959 atomic(const atomic&) = delete;
960 atomic& operator=(const atomic&) = delete;
961 atomic& operator=(const atomic&) volatile = delete;
962
963 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
964
965 using __base_type::operator __integral_type;
966 using __base_type::operator=;
967
968#if __cplusplus >= 201703L
969 static constexpr bool is_always_lock_free = ATOMIC_WCHAR_T_LOCK_FREE == 2;
970#endif
971 };
972
973#ifdef _GLIBCXX_USE_CHAR8_T
974 /// Explicit specialization for char8_t.
975 template<>
976 struct atomic<char8_t> : __atomic_base<char8_t>
977 {
978 typedef char8_t __integral_type;
979 typedef __atomic_base<char8_t> __base_type;
980
981 atomic() noexcept = default;
982 ~atomic() noexcept = default;
983 atomic(const atomic&) = delete;
984 atomic& operator=(const atomic&) = delete;
985 atomic& operator=(const atomic&) volatile = delete;
986
987 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
988
989 using __base_type::operator __integral_type;
990 using __base_type::operator=;
991
992#if __cplusplus > 201402L
993 static constexpr bool is_always_lock_free = ATOMIC_CHAR8_T_LOCK_FREE == 2;
994#endif
995 };
996#endif
997
998 /// Explicit specialization for char16_t.
999 template<>
1000 struct atomic<char16_t> : __atomic_base<char16_t>
1001 {
1002 typedef char16_t __integral_type;
1003 typedef __atomic_base<char16_t> __base_type;
1004
1005 atomic() noexcept = default;
1006 ~atomic() noexcept = default;
1007 atomic(const atomic&) = delete;
1008 atomic& operator=(const atomic&) = delete;
1009 atomic& operator=(const atomic&) volatile = delete;
1010
1011 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
1012
1013 using __base_type::operator __integral_type;
1014 using __base_type::operator=;
1015
1016#if __cplusplus >= 201703L
1017 static constexpr bool is_always_lock_free = ATOMIC_CHAR16_T_LOCK_FREE == 2;
1018#endif
1019 };
1020
1021 /// Explicit specialization for char32_t.
1022 template<>
1023 struct atomic<char32_t> : __atomic_base<char32_t>
1024 {
1025 typedef char32_t __integral_type;
1026 typedef __atomic_base<char32_t> __base_type;
1027
1028 atomic() noexcept = default;
1029 ~atomic() noexcept = default;
1030 atomic(const atomic&) = delete;
1031 atomic& operator=(const atomic&) = delete;
1032 atomic& operator=(const atomic&) volatile = delete;
1033
1034 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
1035
1036 using __base_type::operator __integral_type;
1037 using __base_type::operator=;
1038
1039#if __cplusplus >= 201703L
1040 static constexpr bool is_always_lock_free = ATOMIC_CHAR32_T_LOCK_FREE == 2;
1041#endif
1042 };
1043
1044
1045 /// atomic_bool
1046 typedef atomic<bool> atomic_bool;
1047
1048 /// atomic_char
1049 typedef atomic<char> atomic_char;
1050
1051 /// atomic_schar
1052 typedef atomic<signed char> atomic_schar;
1053
1054 /// atomic_uchar
1055 typedef atomic<unsigned char> atomic_uchar;
1056
1057 /// atomic_short
1058 typedef atomic<short> atomic_short;
1059
1060 /// atomic_ushort
1061 typedef atomic<unsigned short> atomic_ushort;
1062
1063 /// atomic_int
1064 typedef atomic<int> atomic_int;
1065
1066 /// atomic_uint
1067 typedef atomic<unsigned int> atomic_uint;
1068
1069 /// atomic_long
1070 typedef atomic<long> atomic_long;
1071
1072 /// atomic_ulong
1073 typedef atomic<unsigned long> atomic_ulong;
1074
1075 /// atomic_llong
1076 typedef atomic<long long> atomic_llong;
1077
1078 /// atomic_ullong
1079 typedef atomic<unsigned long long> atomic_ullong;
1080
1081 /// atomic_wchar_t
1082 typedef atomic<wchar_t> atomic_wchar_t;
1083
1084#ifdef _GLIBCXX_USE_CHAR8_T
1085 /// atomic_char8_t
1086 typedef atomic<char8_t> atomic_char8_t;
1087#endif
1088
1089 /// atomic_char16_t
1090 typedef atomic<char16_t> atomic_char16_t;
1091
1092 /// atomic_char32_t
1093 typedef atomic<char32_t> atomic_char32_t;
1094
1095#ifdef _GLIBCXX_USE_C99_STDINT_TR1
1096 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1097 // 2441. Exact-width atomic typedefs should be provided
1098
1099 /// atomic_int8_t
1100 typedef atomic<int8_t> atomic_int8_t;
1101
1102 /// atomic_uint8_t
1103 typedef atomic<uint8_t> atomic_uint8_t;
1104
1105 /// atomic_int16_t
1106 typedef atomic<int16_t> atomic_int16_t;
1107
1108 /// atomic_uint16_t
1109 typedef atomic<uint16_t> atomic_uint16_t;
1110
1111 /// atomic_int32_t
1112 typedef atomic<int32_t> atomic_int32_t;
1113
1114 /// atomic_uint32_t
1115 typedef atomic<uint32_t> atomic_uint32_t;
1116
1117 /// atomic_int64_t
1118 typedef atomic<int64_t> atomic_int64_t;
1119
1120 /// atomic_uint64_t
1121 typedef atomic<uint64_t> atomic_uint64_t;
1122
1123
1124 /// atomic_int_least8_t
1125 typedef atomic<int_least8_t> atomic_int_least8_t;
1126
1127 /// atomic_uint_least8_t
1128 typedef atomic<uint_least8_t> atomic_uint_least8_t;
1129
1130 /// atomic_int_least16_t
1131 typedef atomic<int_least16_t> atomic_int_least16_t;
1132
1133 /// atomic_uint_least16_t
1134 typedef atomic<uint_least16_t> atomic_uint_least16_t;
1135
1136 /// atomic_int_least32_t
1137 typedef atomic<int_least32_t> atomic_int_least32_t;
1138
1139 /// atomic_uint_least32_t
1140 typedef atomic<uint_least32_t> atomic_uint_least32_t;
1141
1142 /// atomic_int_least64_t
1143 typedef atomic<int_least64_t> atomic_int_least64_t;
1144
1145 /// atomic_uint_least64_t
1146 typedef atomic<uint_least64_t> atomic_uint_least64_t;
1147
1148
1149 /// atomic_int_fast8_t
1150 typedef atomic<int_fast8_t> atomic_int_fast8_t;
1151
1152 /// atomic_uint_fast8_t
1153 typedef atomic<uint_fast8_t> atomic_uint_fast8_t;
1154
1155 /// atomic_int_fast16_t
1156 typedef atomic<int_fast16_t> atomic_int_fast16_t;
1157
1158 /// atomic_uint_fast16_t
1159 typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
1160
1161 /// atomic_int_fast32_t
1162 typedef atomic<int_fast32_t> atomic_int_fast32_t;
1163
1164 /// atomic_uint_fast32_t
1165 typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
1166
1167 /// atomic_int_fast64_t
1168 typedef atomic<int_fast64_t> atomic_int_fast64_t;
1169
1170 /// atomic_uint_fast64_t
1171 typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
1172#endif
1173
1174
1175 /// atomic_intptr_t
1176 typedef atomic<intptr_t> atomic_intptr_t;
1177
1178 /// atomic_uintptr_t
1179 typedef atomic<uintptr_t> atomic_uintptr_t;
1180
1181 /// atomic_size_t
1182 typedef atomic<size_t> atomic_size_t;
1183
1184 /// atomic_ptrdiff_t
1185 typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
1186
1187#ifdef _GLIBCXX_USE_C99_STDINT_TR1
1188 /// atomic_intmax_t
1189 typedef atomic<intmax_t> atomic_intmax_t;
1190
1191 /// atomic_uintmax_t
1192 typedef atomic<uintmax_t> atomic_uintmax_t;
1193#endif
1194
1195 // Function definitions, atomic_flag operations.
1196 inline bool
1197 atomic_flag_test_and_set_explicit(atomic_flag* __a,
1198 memory_order __m) noexcept
1199 { return __a->test_and_set(__m); }
1200
1201 inline bool
1202 atomic_flag_test_and_set_explicit(volatile atomic_flag* __a,
1203 memory_order __m) noexcept
1204 { return __a->test_and_set(__m); }
1205
1206 inline void
1207 atomic_flag_clear_explicit(atomic_flag* __a, memory_order __m) noexcept
1208 { __a->clear(__m); }
1209
1210 inline void
1211 atomic_flag_clear_explicit(volatile atomic_flag* __a,
1212 memory_order __m) noexcept
1213 { __a->clear(__m); }
1214
1215 inline bool
1216 atomic_flag_test_and_set(atomic_flag* __a) noexcept
1217 { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
1218
1219 inline bool
1220 atomic_flag_test_and_set(volatile atomic_flag* __a) noexcept
1221 { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
1222
1223 inline void
1224 atomic_flag_clear(atomic_flag* __a) noexcept
1225 { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
1226
1227 inline void
1228 atomic_flag_clear(volatile atomic_flag* __a) noexcept
1229 { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
1230
1231
1232 template<typename _Tp>
1233 using __atomic_val_t = typename atomic<_Tp>::value_type;
1234 template<typename _Tp>
1235 using __atomic_diff_t = typename atomic<_Tp>::difference_type;
1236
1237 // [atomics.nonmembers] Non-member functions.
1238 // Function templates generally applicable to atomic types.
1239 template<typename _ITp>
1240 inline bool
1241 atomic_is_lock_free(const atomic<_ITp>* __a) noexcept
1242 { return __a->is_lock_free(); }
1243
1244 template<typename _ITp>
1245 inline bool
1246 atomic_is_lock_free(const volatile atomic<_ITp>* __a) noexcept
1247 { return __a->is_lock_free(); }
1248
1249 template<typename _ITp>
1250 inline void
1251 atomic_init(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1252 { __a->store(__i, memory_order_relaxed); }
1253
1254 template<typename _ITp>
1255 inline void
1256 atomic_init(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1257 { __a->store(__i, memory_order_relaxed); }
1258
1259 template<typename _ITp>
1260 inline void
1261 atomic_store_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1262 memory_order __m) noexcept
1263 { __a->store(__i, __m); }
1264
1265 template<typename _ITp>
1266 inline void
1267 atomic_store_explicit(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1268 memory_order __m) noexcept
1269 { __a->store(__i, __m); }
1270
1271 template<typename _ITp>
1272 inline _ITp
1273 atomic_load_explicit(const atomic<_ITp>* __a, memory_order __m) noexcept
1274 { return __a->load(__m); }
1275
1276 template<typename _ITp>
1277 inline _ITp
1278 atomic_load_explicit(const volatile atomic<_ITp>* __a,
1279 memory_order __m) noexcept
1280 { return __a->load(__m); }
1281
1282 template<typename _ITp>
1283 inline _ITp
1284 atomic_exchange_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1285 memory_order __m) noexcept
1286 { return __a->exchange(__i, __m); }
1287
1288 template<typename _ITp>
1289 inline _ITp
1290 atomic_exchange_explicit(volatile atomic<_ITp>* __a,
1291 __atomic_val_t<_ITp> __i,
1292 memory_order __m) noexcept
1293 { return __a->exchange(__i, __m); }
1294
1295 template<typename _ITp>
1296 inline bool
1297 atomic_compare_exchange_weak_explicit(atomic<_ITp>* __a,
1298 __atomic_val_t<_ITp>* __i1,
1299 __atomic_val_t<_ITp> __i2,
1300 memory_order __m1,
1301 memory_order __m2) noexcept
1302 { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
1303
1304 template<typename _ITp>
1305 inline bool
1306 atomic_compare_exchange_weak_explicit(volatile atomic<_ITp>* __a,
1307 __atomic_val_t<_ITp>* __i1,
1308 __atomic_val_t<_ITp> __i2,
1309 memory_order __m1,
1310 memory_order __m2) noexcept
1311 { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
1312
1313 template<typename _ITp>
1314 inline bool
1315 atomic_compare_exchange_strong_explicit(atomic<_ITp>* __a,
1316 __atomic_val_t<_ITp>* __i1,
1317 __atomic_val_t<_ITp> __i2,
1318 memory_order __m1,
1319 memory_order __m2) noexcept
1320 { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
1321
1322 template<typename _ITp>
1323 inline bool
1324 atomic_compare_exchange_strong_explicit(volatile atomic<_ITp>* __a,
1325 __atomic_val_t<_ITp>* __i1,
1326 __atomic_val_t<_ITp> __i2,
1327 memory_order __m1,
1328 memory_order __m2) noexcept
1329 { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
1330
1331
1332 template<typename _ITp>
1333 inline void
1334 atomic_store(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1335 { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
1336
1337 template<typename _ITp>
1338 inline void
1339 atomic_store(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1340 { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
1341
1342 template<typename _ITp>
1343 inline _ITp
1344 atomic_load(const atomic<_ITp>* __a) noexcept
1345 { return atomic_load_explicit(__a, memory_order_seq_cst); }
1346
1347 template<typename _ITp>
1348 inline _ITp
1349 atomic_load(const volatile atomic<_ITp>* __a) noexcept
1350 { return atomic_load_explicit(__a, memory_order_seq_cst); }
1351
1352 template<typename _ITp>
1353 inline _ITp
1354 atomic_exchange(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1355 { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
1356
1357 template<typename _ITp>
1358 inline _ITp
1359 atomic_exchange(volatile atomic<_ITp>* __a,
1360 __atomic_val_t<_ITp> __i) noexcept
1361 { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
1362
1363 template<typename _ITp>
1364 inline bool
1365 atomic_compare_exchange_weak(atomic<_ITp>* __a,
1366 __atomic_val_t<_ITp>* __i1,
1367 __atomic_val_t<_ITp> __i2) noexcept
1368 {
1369 return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
1370 memory_order_seq_cst,
1371 memory_order_seq_cst);
1372 }
1373
1374 template<typename _ITp>
1375 inline bool
1376 atomic_compare_exchange_weak(volatile atomic<_ITp>* __a,
1377 __atomic_val_t<_ITp>* __i1,
1378 __atomic_val_t<_ITp> __i2) noexcept
1379 {
1380 return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
1381 memory_order_seq_cst,
1382 memory_order_seq_cst);
1383 }
1384
1385 template<typename _ITp>
1386 inline bool
1387 atomic_compare_exchange_strong(atomic<_ITp>* __a,
1388 __atomic_val_t<_ITp>* __i1,
1389 __atomic_val_t<_ITp> __i2) noexcept
1390 {
1391 return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
1392 memory_order_seq_cst,
1393 memory_order_seq_cst);
1394 }
1395
1396 template<typename _ITp>
1397 inline bool
1398 atomic_compare_exchange_strong(volatile atomic<_ITp>* __a,
1399 __atomic_val_t<_ITp>* __i1,
1400 __atomic_val_t<_ITp> __i2) noexcept
1401 {
1402 return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
1403 memory_order_seq_cst,
1404 memory_order_seq_cst);
1405 }
1406
1407
1408#if __cpp_lib_atomic_wait
1409 template<typename _Tp>
1410 inline void
1411 atomic_wait(const atomic<_Tp>* __a,
1412 typename std::atomic<_Tp>::value_type __old) noexcept
1413 { __a->wait(__old); }
1414
1415 template<typename _Tp>
1416 inline void
1417 atomic_wait_explicit(const atomic<_Tp>* __a,
1418 typename std::atomic<_Tp>::value_type __old,
1419 std::memory_order __m) noexcept
1420 { __a->wait(__old, __m); }
1421
1422 template<typename _Tp>
1423 inline void
1424 atomic_notify_one(const atomic<_Tp>* __a) noexcept
1425 { __a->notify_one(); }
1426
1427 template<typename _Tp>
1428 inline void
1429 atomic_notify_all(const atomic<_Tp>* __a) noexcept
1430 { __a->notify_all(); }
1431#endif // __cpp_lib_atomic_wait
1432
1433 // Function templates for atomic_integral and atomic_pointer operations only.
1434 // Some operations (and, or, xor) are only available for atomic integrals,
1435 // which is implemented by taking a parameter of type __atomic_base<_ITp>*.
1436
1437 template<typename _ITp>
1438 inline _ITp
1439 atomic_fetch_add_explicit(atomic<_ITp>* __a,
1440 __atomic_diff_t<_ITp> __i,
1441 memory_order __m) noexcept
1442 { return __a->fetch_add(__i, __m); }
1443
1444 template<typename _ITp>
1445 inline _ITp
1446 atomic_fetch_add_explicit(volatile atomic<_ITp>* __a,
1447 __atomic_diff_t<_ITp> __i,
1448 memory_order __m) noexcept
1449 { return __a->fetch_add(__i, __m); }
1450
1451 template<typename _ITp>
1452 inline _ITp
1453 atomic_fetch_sub_explicit(atomic<_ITp>* __a,
1454 __atomic_diff_t<_ITp> __i,
1455 memory_order __m) noexcept
1456 { return __a->fetch_sub(__i, __m); }
1457
1458 template<typename _ITp>
1459 inline _ITp
1460 atomic_fetch_sub_explicit(volatile atomic<_ITp>* __a,
1461 __atomic_diff_t<_ITp> __i,
1462 memory_order __m) noexcept
1463 { return __a->fetch_sub(__i, __m); }
1464
1465 template<typename _ITp>
1466 inline _ITp
1467 atomic_fetch_and_explicit(__atomic_base<_ITp>* __a,
1468 __atomic_val_t<_ITp> __i,
1469 memory_order __m) noexcept
1470 { return __a->fetch_and(__i, __m); }
1471
1472 template<typename _ITp>
1473 inline _ITp
1474 atomic_fetch_and_explicit(volatile __atomic_base<_ITp>* __a,
1475 __atomic_val_t<_ITp> __i,
1476 memory_order __m) noexcept
1477 { return __a->fetch_and(__i, __m); }
1478
1479 template<typename _ITp>
1480 inline _ITp
1481 atomic_fetch_or_explicit(__atomic_base<_ITp>* __a,
1482 __atomic_val_t<_ITp> __i,
1483 memory_order __m) noexcept
1484 { return __a->fetch_or(__i, __m); }
1485
1486 template<typename _ITp>
1487 inline _ITp
1488 atomic_fetch_or_explicit(volatile __atomic_base<_ITp>* __a,
1489 __atomic_val_t<_ITp> __i,
1490 memory_order __m) noexcept
1491 { return __a->fetch_or(__i, __m); }
1492
1493 template<typename _ITp>
1494 inline _ITp
1495 atomic_fetch_xor_explicit(__atomic_base<_ITp>* __a,
1496 __atomic_val_t<_ITp> __i,
1497 memory_order __m) noexcept
1498 { return __a->fetch_xor(__i, __m); }
1499
1500 template<typename _ITp>
1501 inline _ITp
1502 atomic_fetch_xor_explicit(volatile __atomic_base<_ITp>* __a,
1503 __atomic_val_t<_ITp> __i,
1504 memory_order __m) noexcept
1505 { return __a->fetch_xor(__i, __m); }
1506
1507 template<typename _ITp>
1508 inline _ITp
1509 atomic_fetch_add(atomic<_ITp>* __a,
1510 __atomic_diff_t<_ITp> __i) noexcept
1511 { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
1512
1513 template<typename _ITp>
1514 inline _ITp
1515 atomic_fetch_add(volatile atomic<_ITp>* __a,
1516 __atomic_diff_t<_ITp> __i) noexcept
1517 { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
1518
1519 template<typename _ITp>
1520 inline _ITp
1521 atomic_fetch_sub(atomic<_ITp>* __a,
1522 __atomic_diff_t<_ITp> __i) noexcept
1523 { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
1524
1525 template<typename _ITp>
1526 inline _ITp
1527 atomic_fetch_sub(volatile atomic<_ITp>* __a,
1528 __atomic_diff_t<_ITp> __i) noexcept
1529 { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
1530
1531 template<typename _ITp>
1532 inline _ITp
1533 atomic_fetch_and(__atomic_base<_ITp>* __a,
1534 __atomic_val_t<_ITp> __i) noexcept
1535 { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
1536
1537 template<typename _ITp>
1538 inline _ITp
1539 atomic_fetch_and(volatile __atomic_base<_ITp>* __a,
1540 __atomic_val_t<_ITp> __i) noexcept
1541 { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
1542
1543 template<typename _ITp>
1544 inline _ITp
1545 atomic_fetch_or(__atomic_base<_ITp>* __a,
1546 __atomic_val_t<_ITp> __i) noexcept
1547 { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
1548
1549 template<typename _ITp>
1550 inline _ITp
1551 atomic_fetch_or(volatile __atomic_base<_ITp>* __a,
1552 __atomic_val_t<_ITp> __i) noexcept
1553 { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
1554
1555 template<typename _ITp>
1556 inline _ITp
1557 atomic_fetch_xor(__atomic_base<_ITp>* __a,
1558 __atomic_val_t<_ITp> __i) noexcept
1559 { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
1560
1561 template<typename _ITp>
1562 inline _ITp
1563 atomic_fetch_xor(volatile __atomic_base<_ITp>* __a,
1564 __atomic_val_t<_ITp> __i) noexcept
1565 { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
1566
1567#if __cplusplus > 201703L
1568#define __cpp_lib_atomic_float 201711L
1569 template<>
1570 struct atomic<float> : __atomic_float<float>
1571 {
1572 atomic() noexcept = default;
1573
1574 constexpr
1575 atomic(float __fp) noexcept : __atomic_float<float>(__fp)
1576 { }
1577
1578 atomic& operator=(const atomic&) volatile = delete;
1579 atomic& operator=(const atomic&) = delete;
1580
1581 using __atomic_float<float>::operator=;
1582 };
1583
1584 template<>
1585 struct atomic<double> : __atomic_float<double>
1586 {
1587 atomic() noexcept = default;
1588
1589 constexpr
1590 atomic(double __fp) noexcept : __atomic_float<double>(__fp)
1591 { }
1592
1593 atomic& operator=(const atomic&) volatile = delete;
1594 atomic& operator=(const atomic&) = delete;
1595
1596 using __atomic_float<double>::operator=;
1597 };
1598
1599 template<>
1600 struct atomic<long double> : __atomic_float<long double>
1601 {
1602 atomic() noexcept = default;
1603
1604 constexpr
1605 atomic(long double __fp) noexcept : __atomic_float<long double>(__fp)
1606 { }
1607
1608 atomic& operator=(const atomic&) volatile = delete;
1609 atomic& operator=(const atomic&) = delete;
1610
1611 using __atomic_float<long double>::operator=;
1612 };
1613
1614#define __cpp_lib_atomic_ref 201806L
1615
1616 /// Class template to provide atomic operations on a non-atomic variable.
1617 template<typename _Tp>
1618 struct atomic_ref : __atomic_ref<_Tp>
1619 {
1620 explicit
1621 atomic_ref(_Tp& __t) noexcept : __atomic_ref<_Tp>(__t)
1622 { }
1623
1624 atomic_ref& operator=(const atomic_ref&) = delete;
1625
1626 atomic_ref(const atomic_ref&) = default;
1627
1628 using __atomic_ref<_Tp>::operator=;
1629 };
1630
1631#endif // C++2a
1632
1633 /// @} group atomics
1634
1635_GLIBCXX_END_NAMESPACE_VERSION
1636} // namespace
1637
1638#endif // C++11
1639
1640#endif // _GLIBCXX_ATOMIC
1641