libcxx/include/__stop_token/stop_token.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___STOP_TOKEN_STOP_TOKEN_H
  11 #define _LIBCPP___STOP_TOKEN_STOP_TOKEN_H
  12
  13 #include <__availability>
  14 #include <__config>
  15 #include <__stop_token/intrusive_shared_ptr.h>
  16 #include <__stop_token/stop_state.h>
  17
  18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  19 #  pragma GCC system_header
  20 #endif
  21
  22 _LIBCPP_BEGIN_NAMESPACE_STD
  23
  24 #if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
  25
  26 class _LIBCPP_AVAILABILITY_SYNC stop_token {
  27 public:
  28   _LIBCPP_HIDE_FROM_ABI stop_token() noexcept = default;
  29
  30   _LIBCPP_HIDE_FROM_ABI stop_token(const stop_token&) noexcept            = default;
  31   _LIBCPP_HIDE_FROM_ABI stop_token(stop_token&&) noexcept                 = default;
  32   _LIBCPP_HIDE_FROM_ABI stop_token& operator=(const stop_token&) noexcept = default;
  33   _LIBCPP_HIDE_FROM_ABI stop_token& operator=(stop_token&&) noexcept      = default;
  34   _LIBCPP_HIDE_FROM_ABI ~stop_token()                                     = default;
  35
  36   _LIBCPP_HIDE_FROM_ABI void swap(stop_token& __other) noexcept { __state_.swap(__other.__state_); }
  37
  38   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool stop_requested() const noexcept {
  39     return __state_ != nullptr && __state_->__stop_requested();
  40   }
  41
  42   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool stop_possible() const noexcept {
  43     return __state_ != nullptr && __state_->__stop_possible_for_stop_token();
  44   }
  45
  46   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend bool operator==(const stop_token&, const stop_token&) noexcept = default;
  47
  48   _LIBCPP_HIDE_FROM_ABI friend void swap(stop_token& __lhs, stop_token& __rhs) noexcept { __lhs.swap(__rhs); }
  49
  50 private:
  51   __intrusive_shared_ptr<__stop_state> __state_;
  52
  53   friend class stop_source;
  54   template <class _Tp>
  55   friend class stop_callback;
  56
  57   _LIBCPP_HIDE_FROM_ABI explicit stop_token(const __intrusive_shared_ptr<__stop_state>& __state) : __state_(__state) {}
  58 };
  59
  60 #endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
  61
  62 _LIBCPP_END_NAMESPACE_STD
  63
  64 #endif // _LIBCPP___STOP_TOKEN_STOP_TOKEN_H