3 // Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file bits/atomic_base.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{atomic}
30 #ifndef _GLIBCXX_ATOMIC_BASE_H
31 #define _GLIBCXX_ATOMIC_BASE_H 1
33 #pragma GCC system_header
35 #include <bits/c++config.h>
39 namespace std _GLIBCXX_VISIBILITY(default)
41 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 * @defgroup atomics Atomics
46 * Components for performing atomic operations.
50 /// Enumeration for memory_order
51 typedef enum memory_order
62 __calculate_memory_order(memory_order __m) noexcept
64 const bool __cond1 = __m == memory_order_release;
65 const bool __cond2 = __m == memory_order_acq_rel;
66 memory_order __mo1(__cond1 ? memory_order_relaxed : __m);
67 memory_order __mo2(__cond2 ? memory_order_acquire : __mo1);
72 atomic_thread_fence(memory_order __m) noexcept
74 __atomic_thread_fence (__m);
78 atomic_signal_fence(memory_order __m) noexcept
80 __atomic_thread_fence (__m);
84 template<typename _Tp>
86 kill_dependency(_Tp __y) noexcept
92 /// Lock-free Property
95 #define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE
96 #define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE
97 #define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE
98 #define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE
99 #define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE
100 #define ATOMIC_SHORT_LOCK_FREE __GCC_ATOMIC_SHORT_LOCK_FREE
101 #define ATOMIC_INT_LOCK_FREE __GCC_ATOMIC_INT_LOCK_FREE
102 #define ATOMIC_LONG_LOCK_FREE __GCC_ATOMIC_LONG_LOCK_FREE
103 #define ATOMIC_LLONG_LOCK_FREE __GCC_ATOMIC_LLONG_LOCK_FREE
104 #define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE
106 // Base types for atomics.
107 template<typename _IntTp>
108 struct __atomic_base;
111 typedef __atomic_base<char> atomic_char;
114 typedef __atomic_base<signed char> atomic_schar;
117 typedef __atomic_base<unsigned char> atomic_uchar;
120 typedef __atomic_base<short> atomic_short;
123 typedef __atomic_base<unsigned short> atomic_ushort;
126 typedef __atomic_base<int> atomic_int;
129 typedef __atomic_base<unsigned int> atomic_uint;
132 typedef __atomic_base<long> atomic_long;
135 typedef __atomic_base<unsigned long> atomic_ulong;
138 typedef __atomic_base<long long> atomic_llong;
141 typedef __atomic_base<unsigned long long> atomic_ullong;
144 typedef __atomic_base<wchar_t> atomic_wchar_t;
147 typedef __atomic_base<char16_t> atomic_char16_t;
150 typedef __atomic_base<char32_t> atomic_char32_t;
153 typedef __atomic_base<char32_t> atomic_char32_t;
156 /// atomic_int_least8_t
157 typedef __atomic_base<int_least8_t> atomic_int_least8_t;
159 /// atomic_uint_least8_t
160 typedef __atomic_base<uint_least8_t> atomic_uint_least8_t;
162 /// atomic_int_least16_t
163 typedef __atomic_base<int_least16_t> atomic_int_least16_t;
165 /// atomic_uint_least16_t
166 typedef __atomic_base<uint_least16_t> atomic_uint_least16_t;
168 /// atomic_int_least32_t
169 typedef __atomic_base<int_least32_t> atomic_int_least32_t;
171 /// atomic_uint_least32_t
172 typedef __atomic_base<uint_least32_t> atomic_uint_least32_t;
174 /// atomic_int_least64_t
175 typedef __atomic_base<int_least64_t> atomic_int_least64_t;
177 /// atomic_uint_least64_t
178 typedef __atomic_base<uint_least64_t> atomic_uint_least64_t;
181 /// atomic_int_fast8_t
182 typedef __atomic_base<int_fast8_t> atomic_int_fast8_t;
184 /// atomic_uint_fast8_t
185 typedef __atomic_base<uint_fast8_t> atomic_uint_fast8_t;
187 /// atomic_int_fast16_t
188 typedef __atomic_base<int_fast16_t> atomic_int_fast16_t;
190 /// atomic_uint_fast16_t
191 typedef __atomic_base<uint_fast16_t> atomic_uint_fast16_t;
193 /// atomic_int_fast32_t
194 typedef __atomic_base<int_fast32_t> atomic_int_fast32_t;
196 /// atomic_uint_fast32_t
197 typedef __atomic_base<uint_fast32_t> atomic_uint_fast32_t;
199 /// atomic_int_fast64_t
200 typedef __atomic_base<int_fast64_t> atomic_int_fast64_t;
202 /// atomic_uint_fast64_t
203 typedef __atomic_base<uint_fast64_t> atomic_uint_fast64_t;
207 typedef __atomic_base<intptr_t> atomic_intptr_t;
210 typedef __atomic_base<uintptr_t> atomic_uintptr_t;
213 typedef __atomic_base<size_t> atomic_size_t;
216 typedef __atomic_base<intmax_t> atomic_intmax_t;
219 typedef __atomic_base<uintmax_t> atomic_uintmax_t;
222 typedef __atomic_base<ptrdiff_t> atomic_ptrdiff_t;
225 #define ATOMIC_VAR_INIT(_VI) { _VI }
227 template<typename _Tp>
230 template<typename _Tp>
235 * @brief Base type for atomic_flag.
237 * Base type is POD with data, allowing atomic_flag to derive from
238 * it and meet the standard layout type requirement. In addition to
239 * compatibilty with a C interface, this allows different
240 * implementations of atomic_flag to use the same atomic operation
241 * functions, via a standard conversion to the __atomic_flag_base
244 _GLIBCXX_BEGIN_EXTERN_C
246 struct __atomic_flag_base
251 _GLIBCXX_END_EXTERN_C
253 #define ATOMIC_FLAG_INIT { false }
256 struct atomic_flag : public __atomic_flag_base
258 atomic_flag() noexcept = default;
259 ~atomic_flag() noexcept = default;
260 atomic_flag(const atomic_flag&) = delete;
261 atomic_flag& operator=(const atomic_flag&) = delete;
262 atomic_flag& operator=(const atomic_flag&) volatile = delete;
264 // Conversion to ATOMIC_FLAG_INIT.
265 atomic_flag(bool __i) noexcept : __atomic_flag_base({ __i }) { }
268 test_and_set(memory_order __m = memory_order_seq_cst) noexcept
270 return __atomic_test_and_set (&_M_i, __m);
274 test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept
276 return __atomic_test_and_set (&_M_i, __m);
280 clear(memory_order __m = memory_order_seq_cst) noexcept
282 __glibcxx_assert(__m != memory_order_consume);
283 __glibcxx_assert(__m != memory_order_acquire);
284 __glibcxx_assert(__m != memory_order_acq_rel);
286 __atomic_clear (&_M_i, __m);
290 clear(memory_order __m = memory_order_seq_cst) volatile noexcept
292 __glibcxx_assert(__m != memory_order_consume);
293 __glibcxx_assert(__m != memory_order_acquire);
294 __glibcxx_assert(__m != memory_order_acq_rel);
296 __atomic_clear (&_M_i, __m);
301 /// Base class for atomic integrals.
303 // For each of the integral types, define atomic_[integral type] struct
307 // atomic_schar signed char
308 // atomic_uchar unsigned char
309 // atomic_short short
310 // atomic_ushort unsigned short
312 // atomic_uint unsigned int
314 // atomic_ulong unsigned long
315 // atomic_llong long long
316 // atomic_ullong unsigned long long
317 // atomic_char16_t char16_t
318 // atomic_char32_t char32_t
319 // atomic_wchar_t wchar_t
321 // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or
322 // 8 bytes, since that is what GCC built-in functions for atomic
323 // memory access expect.
324 template<typename _ITp>
328 typedef _ITp __int_type;
333 __atomic_base() noexcept = default;
334 ~__atomic_base() noexcept = default;
335 __atomic_base(const __atomic_base&) = delete;
336 __atomic_base& operator=(const __atomic_base&) = delete;
337 __atomic_base& operator=(const __atomic_base&) volatile = delete;
339 // Requires __int_type convertible to _M_i.
340 constexpr __atomic_base(__int_type __i) noexcept : _M_i (__i) { }
342 operator __int_type() const noexcept
345 operator __int_type() const volatile noexcept
349 operator=(__int_type __i) noexcept
356 operator=(__int_type __i) volatile noexcept
363 operator++(int) noexcept
364 { return fetch_add(1); }
367 operator++(int) volatile noexcept
368 { return fetch_add(1); }
371 operator--(int) noexcept
372 { return fetch_sub(1); }
375 operator--(int) volatile noexcept
376 { return fetch_sub(1); }
379 operator++() noexcept
380 { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); }
383 operator++() volatile noexcept
384 { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); }
387 operator--() noexcept
388 { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); }
391 operator--() volatile noexcept
392 { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); }
395 operator+=(__int_type __i) noexcept
396 { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); }
399 operator+=(__int_type __i) volatile noexcept
400 { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); }
403 operator-=(__int_type __i) noexcept
404 { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); }
407 operator-=(__int_type __i) volatile noexcept
408 { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); }
411 operator&=(__int_type __i) noexcept
412 { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); }
415 operator&=(__int_type __i) volatile noexcept
416 { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); }
419 operator|=(__int_type __i) noexcept
420 { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); }
423 operator|=(__int_type __i) volatile noexcept
424 { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); }
427 operator^=(__int_type __i) noexcept
428 { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); }
431 operator^=(__int_type __i) volatile noexcept
432 { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); }
435 is_lock_free() const noexcept
436 { return __atomic_is_lock_free (sizeof (_M_i), &_M_i); }
439 is_lock_free() const volatile noexcept
440 { return __atomic_is_lock_free (sizeof (_M_i), &_M_i); }
443 store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept
445 __glibcxx_assert(__m != memory_order_acquire);
446 __glibcxx_assert(__m != memory_order_acq_rel);
447 __glibcxx_assert(__m != memory_order_consume);
449 __atomic_store_n(&_M_i, __i, __m);
453 store(__int_type __i,
454 memory_order __m = memory_order_seq_cst) volatile noexcept
456 __glibcxx_assert(__m != memory_order_acquire);
457 __glibcxx_assert(__m != memory_order_acq_rel);
458 __glibcxx_assert(__m != memory_order_consume);
460 __atomic_store_n(&_M_i, __i, __m);
464 load(memory_order __m = memory_order_seq_cst) const noexcept
466 __glibcxx_assert(__m != memory_order_release);
467 __glibcxx_assert(__m != memory_order_acq_rel);
469 return __atomic_load_n(&_M_i, __m);
473 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
475 __glibcxx_assert(__m != memory_order_release);
476 __glibcxx_assert(__m != memory_order_acq_rel);
478 return __atomic_load_n(&_M_i, __m);
482 exchange(__int_type __i,
483 memory_order __m = memory_order_seq_cst) noexcept
485 return __atomic_exchange_n(&_M_i, __i, __m);
490 exchange(__int_type __i,
491 memory_order __m = memory_order_seq_cst) volatile noexcept
493 return __atomic_exchange_n(&_M_i, __i, __m);
497 compare_exchange_weak(__int_type& __i1, __int_type __i2,
498 memory_order __m1, memory_order __m2) noexcept
500 __glibcxx_assert(__m2 != memory_order_release);
501 __glibcxx_assert(__m2 != memory_order_acq_rel);
502 __glibcxx_assert(__m2 <= __m1);
504 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2);
508 compare_exchange_weak(__int_type& __i1, __int_type __i2,
510 memory_order __m2) volatile noexcept
512 __glibcxx_assert(__m2 != memory_order_release);
513 __glibcxx_assert(__m2 != memory_order_acq_rel);
514 __glibcxx_assert(__m2 <= __m1);
516 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2);
520 compare_exchange_weak(__int_type& __i1, __int_type __i2,
521 memory_order __m = memory_order_seq_cst) noexcept
523 return compare_exchange_weak(__i1, __i2, __m,
524 __calculate_memory_order(__m));
528 compare_exchange_weak(__int_type& __i1, __int_type __i2,
529 memory_order __m = memory_order_seq_cst) volatile noexcept
531 return compare_exchange_weak(__i1, __i2, __m,
532 __calculate_memory_order(__m));
536 compare_exchange_strong(__int_type& __i1, __int_type __i2,
537 memory_order __m1, memory_order __m2) noexcept
539 __glibcxx_assert(__m2 != memory_order_release);
540 __glibcxx_assert(__m2 != memory_order_acq_rel);
541 __glibcxx_assert(__m2 <= __m1);
543 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2);
547 compare_exchange_strong(__int_type& __i1, __int_type __i2,
549 memory_order __m2) volatile noexcept
551 __glibcxx_assert(__m2 != memory_order_release);
552 __glibcxx_assert(__m2 != memory_order_acq_rel);
553 __glibcxx_assert(__m2 <= __m1);
555 return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2);
559 compare_exchange_strong(__int_type& __i1, __int_type __i2,
560 memory_order __m = memory_order_seq_cst) noexcept
562 return compare_exchange_strong(__i1, __i2, __m,
563 __calculate_memory_order(__m));
567 compare_exchange_strong(__int_type& __i1, __int_type __i2,
568 memory_order __m = memory_order_seq_cst) volatile noexcept
570 return compare_exchange_strong(__i1, __i2, __m,
571 __calculate_memory_order(__m));
575 fetch_add(__int_type __i,
576 memory_order __m = memory_order_seq_cst) noexcept
577 { return __atomic_fetch_add(&_M_i, __i, __m); }
580 fetch_add(__int_type __i,
581 memory_order __m = memory_order_seq_cst) volatile noexcept
582 { return __atomic_fetch_add(&_M_i, __i, __m); }
585 fetch_sub(__int_type __i,
586 memory_order __m = memory_order_seq_cst) noexcept
587 { return __atomic_fetch_sub(&_M_i, __i, __m); }
590 fetch_sub(__int_type __i,
591 memory_order __m = memory_order_seq_cst) volatile noexcept
592 { return __atomic_fetch_sub(&_M_i, __i, __m); }
595 fetch_and(__int_type __i,
596 memory_order __m = memory_order_seq_cst) noexcept
597 { return __atomic_fetch_and(&_M_i, __i, __m); }
600 fetch_and(__int_type __i,
601 memory_order __m = memory_order_seq_cst) volatile noexcept
602 { return __atomic_fetch_and(&_M_i, __i, __m); }
605 fetch_or(__int_type __i,
606 memory_order __m = memory_order_seq_cst) noexcept
607 { return __atomic_fetch_or(&_M_i, __i, __m); }
610 fetch_or(__int_type __i,
611 memory_order __m = memory_order_seq_cst) volatile noexcept
612 { return __atomic_fetch_or(&_M_i, __i, __m); }
615 fetch_xor(__int_type __i,
616 memory_order __m = memory_order_seq_cst) noexcept
617 { return __atomic_fetch_xor(&_M_i, __i, __m); }
620 fetch_xor(__int_type __i,
621 memory_order __m = memory_order_seq_cst) volatile noexcept
622 { return __atomic_fetch_xor(&_M_i, __i, __m); }
626 /// Partial specialization for pointer types.
627 template<typename _PTp>
628 struct __atomic_base<_PTp*>
631 typedef _PTp* __pointer_type;
636 __atomic_base() noexcept = default;
637 ~__atomic_base() noexcept = default;
638 __atomic_base(const __atomic_base&) = delete;
639 __atomic_base& operator=(const __atomic_base&) = delete;
640 __atomic_base& operator=(const __atomic_base&) volatile = delete;
642 // Requires __pointer_type convertible to _M_p.
643 constexpr __atomic_base(__pointer_type __p) noexcept : _M_p (__p) { }
645 operator __pointer_type() const noexcept
648 operator __pointer_type() const volatile noexcept
652 operator=(__pointer_type __p) noexcept
659 operator=(__pointer_type __p) volatile noexcept
666 operator++(int) noexcept
667 { return fetch_add(1); }
670 operator++(int) volatile noexcept
671 { return fetch_add(1); }
674 operator--(int) noexcept
675 { return fetch_sub(1); }
678 operator--(int) volatile noexcept
679 { return fetch_sub(1); }
682 operator++() noexcept
683 { return __atomic_add_fetch(&_M_p, 1, memory_order_seq_cst); }
686 operator++() volatile noexcept
687 { return __atomic_add_fetch(&_M_p, 1, memory_order_seq_cst); }
690 operator--() noexcept
691 { return __atomic_sub_fetch(&_M_p, 1, memory_order_seq_cst); }
694 operator--() volatile noexcept
695 { return __atomic_sub_fetch(&_M_p, 1, memory_order_seq_cst); }
698 operator+=(ptrdiff_t __d) noexcept
699 { return __atomic_add_fetch(&_M_p, __d, memory_order_seq_cst); }
702 operator+=(ptrdiff_t __d) volatile noexcept
703 { return __atomic_add_fetch(&_M_p, __d, memory_order_seq_cst); }
706 operator-=(ptrdiff_t __d) noexcept
707 { return __atomic_sub_fetch(&_M_p, __d, memory_order_seq_cst); }
710 operator-=(ptrdiff_t __d) volatile noexcept
711 { return __atomic_sub_fetch(&_M_p, __d, memory_order_seq_cst); }
714 is_lock_free() const noexcept
715 { return __atomic_is_lock_free (sizeof (_M_p), &_M_p); }
718 is_lock_free() const volatile noexcept
719 { return __atomic_is_lock_free (sizeof (_M_p), &_M_p); }
722 store(__pointer_type __p,
723 memory_order __m = memory_order_seq_cst) noexcept
725 __glibcxx_assert(__m != memory_order_acquire);
726 __glibcxx_assert(__m != memory_order_acq_rel);
727 __glibcxx_assert(__m != memory_order_consume);
729 __atomic_store_n(&_M_p, __p, __m);
733 store(__pointer_type __p,
734 memory_order __m = memory_order_seq_cst) volatile noexcept
736 __glibcxx_assert(__m != memory_order_acquire);
737 __glibcxx_assert(__m != memory_order_acq_rel);
738 __glibcxx_assert(__m != memory_order_consume);
740 __atomic_store_n(&_M_p, __p, __m);
744 load(memory_order __m = memory_order_seq_cst) const noexcept
746 __glibcxx_assert(__m != memory_order_release);
747 __glibcxx_assert(__m != memory_order_acq_rel);
749 return __atomic_load_n(&_M_p, __m);
753 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
755 __glibcxx_assert(__m != memory_order_release);
756 __glibcxx_assert(__m != memory_order_acq_rel);
758 return __atomic_load_n(&_M_p, __m);
762 exchange(__pointer_type __p,
763 memory_order __m = memory_order_seq_cst) noexcept
765 return __atomic_exchange_n(&_M_p, __p, __m);
770 exchange(__pointer_type __p,
771 memory_order __m = memory_order_seq_cst) volatile noexcept
773 return __atomic_exchange_n(&_M_p, __p, __m);
777 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
779 memory_order __m2) noexcept
781 __glibcxx_assert(__m2 != memory_order_release);
782 __glibcxx_assert(__m2 != memory_order_acq_rel);
783 __glibcxx_assert(__m2 <= __m1);
785 return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, __m1, __m2);
789 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
791 memory_order __m2) volatile noexcept
793 __glibcxx_assert(__m2 != memory_order_release);
794 __glibcxx_assert(__m2 != memory_order_acq_rel);
795 __glibcxx_assert(__m2 <= __m1);
797 return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, __m1, __m2);
801 fetch_add(ptrdiff_t __d,
802 memory_order __m = memory_order_seq_cst) noexcept
803 { return __atomic_fetch_add(&_M_p, __d, __m); }
806 fetch_add(ptrdiff_t __d,
807 memory_order __m = memory_order_seq_cst) volatile noexcept
808 { return __atomic_fetch_add(&_M_p, __d, __m); }
811 fetch_sub(ptrdiff_t __d,
812 memory_order __m = memory_order_seq_cst) noexcept
813 { return __atomic_fetch_sub(&_M_p, __d, __m); }
816 fetch_sub(ptrdiff_t __d,
817 memory_order __m = memory_order_seq_cst) volatile noexcept
818 { return __atomic_fetch_sub(&_M_p, __d, __m); }
823 _GLIBCXX_END_NAMESPACE_VERSION