diff options
Diffstat (limited to 'contrib/llvm-project/libcxx/include/__thread/jthread.h')
| -rw-r--r-- | contrib/llvm-project/libcxx/include/__thread/jthread.h | 130 | 
1 files changed, 130 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__thread/jthread.h b/contrib/llvm-project/libcxx/include/__thread/jthread.h new file mode 100644 index 000000000000..fc86b13afb13 --- /dev/null +++ b/contrib/llvm-project/libcxx/include/__thread/jthread.h @@ -0,0 +1,130 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// 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___THREAD_JTHREAD_H +#define _LIBCPP___THREAD_JTHREAD_H + +#include <__availability> +#include <__config> +#include <__functional/invoke.h> +#include <__stop_token/stop_source.h> +#include <__stop_token/stop_token.h> +#include <__thread/thread.h> +#include <__threading_support> +#include <__type_traits/decay.h> +#include <__type_traits/is_constructible.h> +#include <__type_traits/is_same.h> +#include <__type_traits/remove_cvref.h> +#include <__utility/forward.h> +#include <__utility/move.h> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#  pragma GCC system_header +#endif + +#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) + +_LIBCPP_BEGIN_NAMESPACE_STD + +class _LIBCPP_AVAILABILITY_SYNC jthread { +public: +  // types +  using id                 = thread::id; +  using native_handle_type = thread::native_handle_type; + +  // [thread.jthread.cons], constructors, move, and assignment +  _LIBCPP_HIDE_FROM_ABI jthread() noexcept : __stop_source_(std::nostopstate) {} + +  template <class _Fun, class... _Args> +  _LIBCPP_HIDE_FROM_ABI explicit jthread(_Fun&& __fun, _Args&&... __args) +    requires(!std::is_same_v<remove_cvref_t<_Fun>, jthread>) +      : __stop_source_(), +        __thread_(__init_thread(__stop_source_, std::forward<_Fun>(__fun), std::forward<_Args>(__args)...)) { +    static_assert(is_constructible_v<decay_t<_Fun>, _Fun>); +    static_assert((is_constructible_v<decay_t<_Args>, _Args> && ...)); +    static_assert(is_invocable_v<decay_t<_Fun>, decay_t<_Args>...> || +                  is_invocable_v<decay_t<_Fun>, stop_token, decay_t<_Args>...>); +  } + +  _LIBCPP_HIDE_FROM_ABI ~jthread() { +    if (joinable()) { +      request_stop(); +      join(); +    } +  } + +  jthread(const jthread&) = delete; + +  _LIBCPP_HIDE_FROM_ABI jthread(jthread&&) noexcept = default; + +  jthread& operator=(const jthread&) = delete; + +  _LIBCPP_HIDE_FROM_ABI jthread& operator=(jthread&& __other) noexcept { +    if (this != &__other) { +      if (joinable()) { +        request_stop(); +        join(); +      } +      __stop_source_ = std::move(__other.__stop_source_); +      __thread_      = std::move(__other.__thread_); +    } + +    return *this; +  } + +  // [thread.jthread.mem], members +  _LIBCPP_HIDE_FROM_ABI void swap(jthread& __other) noexcept { +    std::swap(__stop_source_, __other.__stop_source_); +    std::swap(__thread_, __other.__thread_); +  } + +  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool joinable() const noexcept { return get_id() != id(); } + +  _LIBCPP_HIDE_FROM_ABI void join() { __thread_.join(); } + +  _LIBCPP_HIDE_FROM_ABI void detach() { __thread_.detach(); } + +  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI id get_id() const noexcept { return __thread_.get_id(); } + +  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return __thread_.native_handle(); } + +  // [thread.jthread.stop], stop token handling +  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI stop_source get_stop_source() noexcept { return __stop_source_; } + +  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI stop_token get_stop_token() const noexcept { return __stop_source_.get_token(); } + +  _LIBCPP_HIDE_FROM_ABI bool request_stop() noexcept { return __stop_source_.request_stop(); } + +  // [thread.jthread.special], specialized algorithms +  _LIBCPP_HIDE_FROM_ABI friend void swap(jthread& __lhs, jthread& __rhs) noexcept { __lhs.swap(__rhs); } + +  // [thread.jthread.static], static members +  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static unsigned int hardware_concurrency() noexcept { +    return thread::hardware_concurrency(); +  } + +private: +  template <class _Fun, class... _Args> +  _LIBCPP_HIDE_FROM_ABI static thread __init_thread(const stop_source& __ss, _Fun&& __fun, _Args&&... __args) { +    if constexpr (is_invocable_v<decay_t<_Fun>, stop_token, decay_t<_Args>...>) { +      return thread(std::forward<_Fun>(__fun), __ss.get_token(), std::forward<_Args>(__args)...); +    } else { +      return thread(std::forward<_Fun>(__fun), std::forward<_Args>(__args)...); +    } +  } + +  stop_source __stop_source_; +  thread __thread_; +}; + +_LIBCPP_END_NAMESPACE_STD + +#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) + +#endif // _LIBCPP___THREAD_JTHREAD_H  | 
