1//===----------------------------------------------------------------------===//
  2//
  3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4// See https://llvm.org/LICENSE.txt for license information.
  5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6//
  7//===----------------------------------------------------------------------===//
  8
  9#ifndef _LIBCPP___ATOMIC_SUPPORT_H
 10#define _LIBCPP___ATOMIC_SUPPORT_H
 11
 12#include <__config>
 13
 14#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 15#  pragma GCC system_header
 16#endif
 17
 18//
 19// This file implements base support for atomics on the platform.
 20//
 21// The following operations and types must be implemented (where _Atmc
 22// is __cxx_atomic_base_impl for readability):
 23//
 24// clang-format off
 25//
 26// template <class _Tp>
 27// struct __cxx_atomic_base_impl;
 28//
 29// #define __cxx_atomic_is_lock_free(__size)
 30//
 31// void __cxx_atomic_thread_fence(memory_order __order) noexcept;
 32// void __cxx_atomic_signal_fence(memory_order __order) noexcept;
 33//
 34// template <class _Tp>
 35// void __cxx_atomic_init(_Atmc<_Tp> volatile* __a, _Tp __val) noexcept;
 36// template <class _Tp>
 37// void __cxx_atomic_init(_Atmc<_Tp>* __a, _Tp __val) noexcept;
 38//
 39// template <class _Tp>
 40// void __cxx_atomic_store(_Atmc<_Tp> volatile* __a, _Tp __val, memory_order __order) noexcept;
 41// template <class _Tp>
 42// void __cxx_atomic_store(_Atmc<_Tp>* __a, _Tp __val, memory_order __order) noexcept;
 43//
 44// template <class _Tp>
 45// _Tp __cxx_atomic_load(_Atmc<_Tp> const volatile* __a, memory_order __order) noexcept;
 46// template <class _Tp>
 47// _Tp __cxx_atomic_load(_Atmc<_Tp> const* __a, memory_order __order) noexcept;
 48//
 49// template <class _Tp>
 50// void __cxx_atomic_load_inplace(_Atmc<_Tp> const volatile* __a, _Tp* __dst, memory_order __order) noexcept;
 51// template <class _Tp>
 52// void __cxx_atomic_load_inplace(_Atmc<_Tp> const* __a, _Tp* __dst, memory_order __order) noexcept;
 53//
 54// template <class _Tp>
 55// _Tp __cxx_atomic_exchange(_Atmc<_Tp> volatile* __a, _Tp __value, memory_order __order) noexcept;
 56// template <class _Tp>
 57// _Tp __cxx_atomic_exchange(_Atmc<_Tp>* __a, _Tp __value, memory_order __order) noexcept;
 58//
 59// template <class _Tp>
 60// bool __cxx_atomic_compare_exchange_strong(_Atmc<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) noexcept;
 61// template <class _Tp>
 62// bool __cxx_atomic_compare_exchange_strong(_Atmc<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) noexcept;
 63//
 64// template <class _Tp>
 65// bool __cxx_atomic_compare_exchange_weak(_Atmc<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) noexcept;
 66// template <class _Tp>
 67// bool __cxx_atomic_compare_exchange_weak(_Atmc<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) noexcept;
 68//
 69// template <class _Tp>
 70// _Tp __cxx_atomic_fetch_add(_Atmc<_Tp> volatile* __a, _Tp __delta, memory_order __order) noexcept;
 71// template <class _Tp>
 72// _Tp __cxx_atomic_fetch_add(_Atmc<_Tp>* __a, _Tp __delta, memory_order __order) noexcept;
 73//
 74// template <class _Tp>
 75// _Tp* __cxx_atomic_fetch_add(_Atmc<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) noexcept;
 76// template <class _Tp>
 77// _Tp* __cxx_atomic_fetch_add(_Atmc<_Tp*>* __a, ptrdiff_t __delta, memory_order __order) noexcept;
 78//
 79// template <class _Tp>
 80// _Tp __cxx_atomic_fetch_sub(_Atmc<_Tp> volatile* __a, _Tp __delta, memory_order __order) noexcept;
 81// template <class _Tp>
 82// _Tp __cxx_atomic_fetch_sub(_Atmc<_Tp>* __a, _Tp __delta, memory_order __order) noexcept;
 83// template <class _Tp>
 84// _Tp* __cxx_atomic_fetch_sub(_Atmc<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) noexcept;
 85// template <class _Tp>
 86// _Tp* __cxx_atomic_fetch_sub(_Atmc<_Tp*>* __a, ptrdiff_t __delta, memory_order __order) noexcept;
 87//
 88// template <class _Tp>
 89// _Tp __cxx_atomic_fetch_and(_Atmc<_Tp> volatile* __a, _Tp __pattern, memory_order __order) noexcept;
 90// template <class _Tp>
 91// _Tp __cxx_atomic_fetch_and(_Atmc<_Tp>* __a, _Tp __pattern, memory_order __order) noexcept;
 92//
 93// template <class _Tp>
 94// _Tp __cxx_atomic_fetch_or(_Atmc<_Tp> volatile* __a, _Tp __pattern, memory_order __order) noexcept;
 95// template <class _Tp>
 96// _Tp __cxx_atomic_fetch_or(_Atmc<_Tp>* __a, _Tp __pattern, memory_order __order) noexcept;
 97// template <class _Tp>
 98// _Tp __cxx_atomic_fetch_xor(_Atmc<_Tp> volatile* __a, _Tp __pattern, memory_order __order) noexcept;
 99// template <class _Tp>
100// _Tp __cxx_atomic_fetch_xor(_Atmc<_Tp>* __a, _Tp __pattern, memory_order __order) noexcept;
101//
102// clang-format on
103//
104
105#if _LIBCPP_HAS_GCC_ATOMIC_IMP
106#  include <__atomic/support/gcc.h>
107#elif _LIBCPP_HAS_C_ATOMIC_IMP
108#  include <__atomic/support/c11.h>
109#endif
110
111_LIBCPP_BEGIN_NAMESPACE_STD
112
113template <typename _Tp, typename _Base = __cxx_atomic_base_impl<_Tp> >
114struct __cxx_atomic_impl : public _Base {
115  _LIBCPP_HIDE_FROM_ABI __cxx_atomic_impl() _NOEXCEPT = default;
116  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __cxx_atomic_impl(_Tp __value) _NOEXCEPT : _Base(__value) {}
117};
118
119_LIBCPP_END_NAMESPACE_STD
120
121#endif // _LIBCPP___ATOMIC_SUPPORT_H