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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-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___STOP_TOKEN_STOP_SOURCE_H11#define _LIBCPP___STOP_TOKEN_STOP_SOURCE_H12 13#include <__config>14#include <__stop_token/intrusive_shared_ptr.h>15#include <__stop_token/stop_state.h>16#include <__stop_token/stop_token.h>17#include <__utility/move.h>18 19#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)20# pragma GCC system_header21#endif22 23_LIBCPP_BEGIN_NAMESPACE_STD24 25#if _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_THREADS26 27struct nostopstate_t {28 explicit nostopstate_t() = default;29};30 31inline constexpr nostopstate_t nostopstate{};32 33class stop_source {34public:35 _LIBCPP_HIDE_FROM_ABI stop_source() : __state_(new __stop_state()) { __state_->__increment_stop_source_counter(); }36 37 _LIBCPP_HIDE_FROM_ABI explicit stop_source(nostopstate_t) noexcept : __state_(nullptr) {}38 39 _LIBCPP_HIDE_FROM_ABI stop_source(const stop_source& __other) noexcept : __state_(__other.__state_) {40 if (__state_) {41 __state_->__increment_stop_source_counter();42 }43 }44 45 _LIBCPP_HIDE_FROM_ABI stop_source(stop_source&& __other) noexcept = default;46 47 _LIBCPP_HIDE_FROM_ABI stop_source& operator=(const stop_source& __other) noexcept {48 // increment `__other` first so that we don't hit 0 in case of self-assignment49 if (__other.__state_) {50 __other.__state_->__increment_stop_source_counter();51 }52 if (__state_) {53 __state_->__decrement_stop_source_counter();54 }55 __state_ = __other.__state_;56 return *this;57 }58 59 _LIBCPP_HIDE_FROM_ABI stop_source& operator=(stop_source&&) noexcept = default;60 61 _LIBCPP_HIDE_FROM_ABI ~stop_source() {62 if (__state_) {63 __state_->__decrement_stop_source_counter();64 }65 }66 67 _LIBCPP_HIDE_FROM_ABI void swap(stop_source& __other) noexcept { __state_.swap(__other.__state_); }68 69 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI stop_token get_token() const noexcept { return stop_token(__state_); }70 71 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool stop_possible() const noexcept { return __state_ != nullptr; }72 73 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool stop_requested() const noexcept {74 return __state_ != nullptr && __state_->__stop_requested();75 }76 77 _LIBCPP_HIDE_FROM_ABI bool request_stop() noexcept { return __state_ && __state_->__request_stop(); }78 79 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend bool operator==(const stop_source&, const stop_source&) noexcept = default;80 81 _LIBCPP_HIDE_FROM_ABI friend void swap(stop_source& __lhs, stop_source& __rhs) noexcept { __lhs.swap(__rhs); }82 83private:84 __intrusive_shared_ptr<__stop_state> __state_;85};86 87#endif // _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_THREADS88 89_LIBCPP_END_NAMESPACE_STD90 91#endif // _LIBCPP___STOP_TOKEN_STOP_SOURCE_H92