//===----------------------------------------------------------------------===//
//
// 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_FLAG_H
#define _LIBCPP___ATOMIC_ATOMIC_FLAG_H

#include <__atomic/atomic_sync.h>
#include <__atomic/atomic_waitable_traits.h>
#include <__atomic/contention_t.h>
#include <__atomic/memory_order.h>
#include <__atomic/support.h>
#include <__chrono/duration.h>
#include <__config>
#include <__memory/addressof.h>
#include <__thread/support.h>
#include <cstdint>

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

_LIBCPP_BEGIN_NAMESPACE_STD

struct atomic_flag {
  __cxx_atomic_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_;

  _LIBCPP_HIDE_FROM_ABI bool test(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT {
    return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);
  }
  _LIBCPP_HIDE_FROM_ABI bool test(memory_order __m = memory_order_seq_cst) const _NOEXCEPT {
    return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);
  }

  _LIBCPP_HIDE_FROM_ABI bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);
  }
  _LIBCPP_HIDE_FROM_ABI bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);
  }
  _LIBCPP_HIDE_FROM_ABI void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
    __cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);
  }
  _LIBCPP_HIDE_FROM_ABI void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT {
    __cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);
  }

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

#if _LIBCPP_STD_VER >= 20
  _LIBCPP_HIDE_FROM_ABI constexpr atomic_flag() _NOEXCEPT : __a_(false) {}
#else
  atomic_flag() _NOEXCEPT = default;
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {} // EXTENSION

  atomic_flag(const atomic_flag&)                     = delete;
  atomic_flag& operator=(const atomic_flag&)          = delete;
  atomic_flag& operator=(const atomic_flag&) volatile = delete;
};

#if _LIBCPP_STD_VER >= 20
template <>
struct __atomic_waitable_traits<atomic_flag> {
  using __value_type _LIBCPP_NODEBUG = _LIBCPP_ATOMIC_FLAG_TYPE;

  static _LIBCPP_HIDE_FROM_ABI _LIBCPP_ATOMIC_FLAG_TYPE __atomic_load(const atomic_flag& __a, memory_order __order) {
    return std::__cxx_atomic_load(&__a.__a_, __order);
  }

  static _LIBCPP_HIDE_FROM_ABI _LIBCPP_ATOMIC_FLAG_TYPE
  __atomic_load(const volatile atomic_flag& __a, memory_order __order) {
    return std::__cxx_atomic_load(&__a.__a_, __order);
  }

  static _LIBCPP_HIDE_FROM_ABI const __cxx_atomic_impl<_LIBCPP_ATOMIC_FLAG_TYPE>*
  __atomic_contention_address(const atomic_flag& __a) {
    return std::addressof(__a.__a_);
  }

  static _LIBCPP_HIDE_FROM_ABI const volatile __cxx_atomic_impl<_LIBCPP_ATOMIC_FLAG_TYPE>*
  __atomic_contention_address(const volatile atomic_flag& __a) {
    return std::addressof(__a.__a_);
  }
};
#endif // _LIBCPP_STD_VER >= 20

inline _LIBCPP_HIDE_FROM_ABI bool atomic_flag_test(const volatile atomic_flag* __o) _NOEXCEPT { return __o->test(); }

inline _LIBCPP_HIDE_FROM_ABI bool atomic_flag_test(const atomic_flag* __o) _NOEXCEPT { return __o->test(); }

inline _LIBCPP_HIDE_FROM_ABI bool
atomic_flag_test_explicit(const volatile atomic_flag* __o, memory_order __m) _NOEXCEPT {
  return __o->test(__m);
}

inline _LIBCPP_HIDE_FROM_ABI bool atomic_flag_test_explicit(const atomic_flag* __o, memory_order __m) _NOEXCEPT {
  return __o->test(__m);
}

inline _LIBCPP_HIDE_FROM_ABI bool atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT {
  return __o->test_and_set();
}

inline _LIBCPP_HIDE_FROM_ABI bool atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT { return __o->test_and_set(); }

inline _LIBCPP_HIDE_FROM_ABI bool
atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT {
  return __o->test_and_set(__m);
}

inline _LIBCPP_HIDE_FROM_ABI bool atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT {
  return __o->test_and_set(__m);
}

inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT { __o->clear(); }

inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_clear(atomic_flag* __o) _NOEXCEPT { __o->clear(); }

inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT {
  __o->clear(__m);
}

inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT {
  __o->clear(__m);
}

#if _LIBCPP_STD_VER >= 20
inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_wait(const volatile atomic_flag* __o, bool __v) _NOEXCEPT {
  __o->wait(__v);
}

inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_wait(const atomic_flag* __o, bool __v) _NOEXCEPT { __o->wait(__v); }

inline _LIBCPP_HIDE_FROM_ABI void
atomic_flag_wait_explicit(const volatile atomic_flag* __o, bool __v, memory_order __m) _NOEXCEPT {
  __o->wait(__v, __m);
}

inline _LIBCPP_HIDE_FROM_ABI void
atomic_flag_wait_explicit(const atomic_flag* __o, bool __v, memory_order __m) _NOEXCEPT {
  __o->wait(__v, __m);
}

inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_notify_one(volatile atomic_flag* __o) _NOEXCEPT { __o->notify_one(); }
inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_notify_one(atomic_flag* __o) _NOEXCEPT { __o->notify_one(); }
inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_notify_all(volatile atomic_flag* __o) _NOEXCEPT { __o->notify_all(); }
inline _LIBCPP_HIDE_FROM_ABI void atomic_flag_notify_all(atomic_flag* __o) _NOEXCEPT { __o->notify_all(); }
#endif // _LIBCPP_STD_VER >= 20

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___ATOMIC_ATOMIC_FLAG_H
