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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_CALLBACK_H11#define _LIBCPP___STOP_TOKEN_STOP_CALLBACK_H12 13#include <__concepts/constructible.h>14#include <__concepts/destructible.h>15#include <__concepts/invocable.h>16#include <__config>17#include <__stop_token/intrusive_shared_ptr.h>18#include <__stop_token/stop_state.h>19#include <__stop_token/stop_token.h>20#include <__type_traits/is_nothrow_constructible.h>21#include <__utility/forward.h>22#include <__utility/move.h>23#include <__utility/private_constructor_tag.h>24 25#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)26# pragma GCC system_header27#endif28 29_LIBCPP_PUSH_MACROS30#include <__undef_macros>31 32_LIBCPP_BEGIN_NAMESPACE_STD33 34#if _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_THREADS35 36template <class _Callback>37class stop_callback : private __stop_callback_base {38 static_assert(invocable<_Callback>,39 "Mandates: stop_callback is instantiated with an argument for the template parameter Callback that "40 "satisfies invocable.");41 static_assert(destructible<_Callback>,42 "Mandates: stop_callback is instantiated with an argument for the template parameter Callback that "43 "satisfies destructible.");44 45public:46 using callback_type = _Callback;47 48 template <class _Cb>49 requires constructible_from<_Callback, _Cb>50 _LIBCPP_HIDE_FROM_ABI explicit stop_callback(const stop_token& __st,51 _Cb&& __cb) noexcept(is_nothrow_constructible_v<_Callback, _Cb>)52 : stop_callback(__private_constructor_tag{}, __st.__state_, std::forward<_Cb>(__cb)) {}53 54 template <class _Cb>55 requires constructible_from<_Callback, _Cb>56 _LIBCPP_HIDE_FROM_ABI explicit stop_callback(stop_token&& __st,57 _Cb&& __cb) noexcept(is_nothrow_constructible_v<_Callback, _Cb>)58 : stop_callback(__private_constructor_tag{}, std::move(__st.__state_), std::forward<_Cb>(__cb)) {}59 60 _LIBCPP_HIDE_FROM_ABI ~stop_callback() {61 if (__state_) {62 __state_->__remove_callback(this);63 }64 }65 66 stop_callback(const stop_callback&) = delete;67 stop_callback(stop_callback&&) = delete;68 stop_callback& operator=(const stop_callback&) = delete;69 stop_callback& operator=(stop_callback&&) = delete;70 71private:72 _LIBCPP_NO_UNIQUE_ADDRESS _Callback __callback_;73 __intrusive_shared_ptr<__stop_state> __state_;74 75 friend __stop_callback_base;76 77 template <class _StatePtr, class _Cb>78 _LIBCPP_HIDE_FROM_ABI explicit stop_callback(__private_constructor_tag, _StatePtr&& __state, _Cb&& __cb) noexcept(79 is_nothrow_constructible_v<_Callback, _Cb>)80 : __stop_callback_base([](__stop_callback_base* __cb_base) noexcept {81 // stop callback is supposed to only be called once82 std::forward<_Callback>(static_cast<stop_callback*>(__cb_base)->__callback_)();83 }),84 __callback_(std::forward<_Cb>(__cb)),85 __state_() {86 if (__state && __state->__add_callback(this)) {87 // st.stop_requested() was false and this is successfully added to the linked list88 __state_ = std::forward<_StatePtr>(__state);89 }90 }91};92 93template <class _Callback>94stop_callback(stop_token, _Callback) -> stop_callback<_Callback>;95 96#endif // _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_THREADS97 98_LIBCPP_END_NAMESPACE_STD99 100_LIBCPP_POP_MACROS101 102#endif // _LIBCPP___STOP_TOKEN_STOP_CALLBACK_H103