libcxx/include/__atomic/atomic_base.h

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ATOMIC_ATOMIC_BASE_H
#define _LIBCPP___ATOMIC_ATOMIC_BASE_H

#include <__atomic/atomic_sync.h>
#include <__atomic/check_memory_order.h>
#include <__atomic/cxx_atomic_impl.h>
#include <__atomic/is_always_lock_free.h>
#include <__atomic/memory_order.h>
#include <__config>
#include <__memory/addressof.h>
#include <__type_traits/is_integral.h>
#include <__type_traits/is_nothrow_constructible.h>
#include <__type_traits/is_same.h>
#include <version>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value>
struct __atomic_base // false
{
  mutable __cxx_atomic_impl<_Tp> __a_;

#if _LIBCPP_STD_VER >= 17
  static constexpr bool is_always_lock_free = __libcpp_is_always_lock_free<__cxx_atomic_impl<_Tp> >::__value;
#endif

  _LIBCPP_HIDE_FROM_ABI bool is_lock_free() const volatile _NOEXCEPT {
    return __cxx_atomic_is_lock_free(sizeof(__cxx_atomic_impl<_Tp>));
  }
  _LIBCPP_HIDE_FROM_ABI bool is_lock_free() const _NOEXCEPT {
    return static_cast<__atomic_base const volatile*>(this)->is_lock_free();
  }
  _LIBCPP_HIDE_FROM_ABI void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) {
    std::__cxx_atomic_store(std::addressof(__a_), __d, __m);
  }
  _LIBCPP_HIDE_FROM_ABI void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) {
    std::__cxx_atomic_store(std::addressof(__a_), __d, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) {
    return std::__cxx_atomic_load(std::addressof(__a_), __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) {
    return std::__cxx_atomic_load(std::addressof(__a_), __m);
  }
  _LIBCPP_HIDE_FROM_ABI operator _Tp() const volatile _NOEXCEPT { return load(); }
  _LIBCPP_HIDE_FROM_ABI operator _Tp() const _NOEXCEPT { return load(); }
  _LIBCPP_HIDE_FROM_ABI _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_exchange(std::addressof(__a_), __d, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_exchange(std::addressof(__a_), __d, __m);
  }
  _LIBCPP_HIDE_FROM_ABI bool
  compare_exchange_weak(_Tp& __e, _Tp __d, memory_order __s, memory_order __f) volatile _NOEXCEPT
      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) {
    return std::__cxx_atomic_compare_exchange_weak(std::addressof(__a_), std::addressof(__e), __d, __s, __f);
  }
  _LIBCPP_HIDE_FROM_ABI bool compare_exchange_weak(_Tp& __e, _Tp __d, memory_order __s, memory_order __f) _NOEXCEPT
      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) {
    return std::__cxx_atomic_compare_exchange_weak(std::addressof(__a_), std::addressof(__e), __d, __s, __f);
  }
  _LIBCPP_HIDE_FROM_ABI bool
  compare_exchange_strong(_Tp& __e, _Tp __d, memory_order __s, memory_order __f) volatile _NOEXCEPT
      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) {
    return std::__cxx_atomic_compare_exchange_strong(std::addressof(__a_), std::addressof(__e), __d, __s, __f);
  }
  _LIBCPP_HIDE_FROM_ABI bool compare_exchange_strong(_Tp& __e, _Tp __d, memory_order __s, memory_order __f) _NOEXCEPT
      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) {
    return std::__cxx_atomic_compare_exchange_strong(std::addressof(__a_), std::addressof(__e), __d, __s, __f);
  }
  _LIBCPP_HIDE_FROM_ABI bool
  compare_exchange_weak(_Tp& __e, _Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_compare_exchange_weak(std::addressof(__a_), std::addressof(__e), __d, __m, __m);
  }
  _LIBCPP_HIDE_FROM_ABI bool
  compare_exchange_weak(_Tp& __e, _Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_compare_exchange_weak(std::addressof(__a_), std::addressof(__e), __d, __m, __m);
  }
  _LIBCPP_HIDE_FROM_ABI bool
  compare_exchange_strong(_Tp& __e, _Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_compare_exchange_strong(std::addressof(__a_), std::addressof(__e), __d, __m, __m);
  }
  _LIBCPP_HIDE_FROM_ABI bool
  compare_exchange_strong(_Tp& __e, _Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_compare_exchange_strong(std::addressof(__a_), std::addressof(__e), __d, __m, __m);
  }

#if _LIBCPP_STD_VER >= 20
  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const
      volatile _NOEXCEPT {
    std::__atomic_wait(*this, __v, __m);
  }
  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI void
  wait(_Tp __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT {
    std::__atomic_wait(*this, __v, __m);
  }
  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI void notify_one() volatile _NOEXCEPT {
    std::__atomic_notify_one(*this);
  }
  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI void notify_one() _NOEXCEPT { std::__atomic_notify_one(*this); }
  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI void notify_all() volatile _NOEXCEPT {
    std::__atomic_notify_all(*this);
  }
  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI void notify_all() _NOEXCEPT { std::__atomic_notify_all(*this); }
#endif //  _LIBCPP_STD_VER >= 20

#if _LIBCPP_STD_VER >= 20
  _LIBCPP_HIDE_FROM_ABI constexpr __atomic_base() noexcept(is_nothrow_default_constructible_v<_Tp>) : __a_(_Tp()) {}
#else
  _LIBCPP_HIDE_FROM_ABI __atomic_base() _NOEXCEPT = default;
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {}

  __atomic_base(const __atomic_base&) = delete;
};

// atomic<Integral>

template <class _Tp>
struct __atomic_base<_Tp, true> : public __atomic_base<_Tp, false> {
  using __base = __atomic_base<_Tp, false>;

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __atomic_base() _NOEXCEPT = default;

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}

  _LIBCPP_HIDE_FROM_ABI _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_fetch_add(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_fetch_add(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_fetch_sub(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_fetch_sub(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_fetch_and(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_fetch_and(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_fetch_or(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_fetch_or(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return std::__cxx_atomic_fetch_xor(std::addressof(this->__a_), __op, __m);
  }
  _LIBCPP_HIDE_FROM_ABI _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return std::__cxx_atomic_fetch_xor(std::addressof(this->__a_), __op, __m);
  }

  _LIBCPP_HIDE_FROM_ABI _Tp operator++(int) volatile _NOEXCEPT { return fetch_add(_Tp(1)); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator++(int) _NOEXCEPT { return fetch_add(_Tp(1)); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator--(int) volatile _NOEXCEPT { return fetch_sub(_Tp(1)); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator--(int) _NOEXCEPT { return fetch_sub(_Tp(1)); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator++() volatile _NOEXCEPT { return fetch_add(_Tp(1)) + _Tp(1); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator++() _NOEXCEPT { return fetch_add(_Tp(1)) + _Tp(1); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator--() volatile _NOEXCEPT { return fetch_sub(_Tp(1)) - _Tp(1); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator--() _NOEXCEPT { return fetch_sub(_Tp(1)) - _Tp(1); }
  _LIBCPP_HIDE_FROM_ABI _Tp operator+=(_Tp __op) volatile _NOEXCEPT { return fetch_add(__op) + __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator+=(_Tp __op) _NOEXCEPT { return fetch_add(__op) + __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator-=(_Tp __op) volatile _NOEXCEPT { return fetch_sub(__op) - __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator-=(_Tp __op) _NOEXCEPT { return fetch_sub(__op) - __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator&=(_Tp __op) volatile _NOEXCEPT { return fetch_and(__op) & __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator&=(_Tp __op) _NOEXCEPT { return fetch_and(__op) & __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator|=(_Tp __op) volatile _NOEXCEPT { return fetch_or(__op) | __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator|=(_Tp __op) _NOEXCEPT { return fetch_or(__op) | __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator^=(_Tp __op) volatile _NOEXCEPT { return fetch_xor(__op) ^ __op; }
  _LIBCPP_HIDE_FROM_ABI _Tp operator^=(_Tp __op) _NOEXCEPT { return fetch_xor(__op) ^ __op; }
};

// Here we need _IsIntegral because the default template argument is not enough
// e.g  __atomic_base<int> is __atomic_base<int, true>, which inherits from
// __atomic_base<int, false> and the caller of the wait function is
// __atomic_base<int, false>. So specializing __atomic_base<_Tp> does not work
template <class _Tp, bool _IsIntegral>
struct __atomic_waitable_traits<__atomic_base<_Tp, _IsIntegral> > {
  static _LIBCPP_HIDE_FROM_ABI _Tp __atomic_load(const __atomic_base<_Tp, _IsIntegral>& __a, memory_order __order) {
    return __a.load(__order);
  }

  static _LIBCPP_HIDE_FROM_ABI _Tp
  __atomic_load(const volatile __atomic_base<_Tp, _IsIntegral>& __this, memory_order __order) {
    return __this.load(__order);
  }

  static _LIBCPP_HIDE_FROM_ABI const __cxx_atomic_impl<_Tp>*
  __atomic_contention_address(const __atomic_base<_Tp, _IsIntegral>& __a) {
    return std::addressof(__a.__a_);
  }

  static _LIBCPP_HIDE_FROM_ABI const volatile __cxx_atomic_impl<_Tp>*
  __atomic_contention_address(const volatile __atomic_base<_Tp, _IsIntegral>& __this) {
    return std::addressof(__this.__a_);
  }
};

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___ATOMIC_ATOMIC_BASE_H