178 lines · c
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___COROUTINE_COROUTINE_HANDLE_H10#define _LIBCPP___COROUTINE_COROUTINE_HANDLE_H11 12#include <__assert>13#include <__config>14#include <__cstddef/nullptr_t.h>15#include <__cstddef/size_t.h>16#include <__functional/hash.h>17#include <__memory/addressof.h>18#include <__type_traits/remove_cv.h>19#include <compare>20 21#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)22# pragma GCC system_header23#endif24 25#if _LIBCPP_STD_VER >= 2026 27_LIBCPP_BEGIN_NAMESPACE_STD28 29// [coroutine.handle]30template <class _Promise = void>31struct coroutine_handle;32 33template <>34struct coroutine_handle<void> {35public:36 // [coroutine.handle.con], construct/reset37 constexpr coroutine_handle() noexcept = default;38 39 _LIBCPP_HIDE_FROM_ABI constexpr coroutine_handle(nullptr_t) noexcept {}40 41 _LIBCPP_HIDE_FROM_ABI coroutine_handle& operator=(nullptr_t) noexcept {42 __handle_ = nullptr;43 return *this;44 }45 46 // [coroutine.handle.export.import], export/import47 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr void* address() const noexcept { return __handle_; }48 49 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr coroutine_handle from_address(void* __addr) noexcept {50 coroutine_handle __tmp;51 __tmp.__handle_ = __addr;52 return __tmp;53 }54 55 // [coroutine.handle.observers], observers56 _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __handle_ != nullptr; }57 58 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool done() const {59 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(__is_suspended(), "done() can be called only on suspended coroutines");60 return __builtin_coro_done(__handle_);61 }62 63 // [coroutine.handle.resumption], resumption64 _LIBCPP_HIDE_FROM_ABI void operator()() const { resume(); }65 66 _LIBCPP_HIDE_FROM_ABI void resume() const {67 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(__is_suspended(), "resume() can be called only on suspended coroutines");68 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(!done(), "resume() has undefined behavior when the coroutine is done");69 __builtin_coro_resume(__handle_);70 }71 72 _LIBCPP_HIDE_FROM_ABI void destroy() const {73 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(__is_suspended(), "destroy() can be called only on suspended coroutines");74 __builtin_coro_destroy(__handle_);75 }76 77private:78 _LIBCPP_HIDE_FROM_ABI bool __is_suspended() const {79 // FIXME actually implement a check for if the coro is suspended.80 return __handle_ != nullptr;81 }82 83 void* __handle_ = nullptr;84};85 86// [coroutine.handle.compare]87inline _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {88 return __x.address() == __y.address();89}90inline _LIBCPP_HIDE_FROM_ABI constexpr strong_ordering91operator<=>(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {92 return compare_three_way()(__x.address(), __y.address());93}94 95template <class _Promise>96struct coroutine_handle {97public:98 // [coroutine.handle.con], construct/reset99 constexpr coroutine_handle() noexcept = default;100 101 _LIBCPP_HIDE_FROM_ABI constexpr coroutine_handle(nullptr_t) noexcept {}102 103 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static coroutine_handle from_promise(_Promise& __promise) {104 using _RawPromise = __remove_cv_t<_Promise>;105 coroutine_handle __tmp;106 __tmp.__handle_ =107 __builtin_coro_promise(std::addressof(const_cast<_RawPromise&>(__promise)), alignof(_Promise), true);108 return __tmp;109 }110 111 _LIBCPP_HIDE_FROM_ABI coroutine_handle& operator=(nullptr_t) noexcept {112 __handle_ = nullptr;113 return *this;114 }115 116 // [coroutine.handle.export.import], export/import117 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr void* address() const noexcept { return __handle_; }118 119 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr coroutine_handle from_address(void* __addr) noexcept {120 coroutine_handle __tmp;121 __tmp.__handle_ = __addr;122 return __tmp;123 }124 125 // [coroutine.handle.conv], conversion126 _LIBCPP_HIDE_FROM_ABI constexpr operator coroutine_handle<>() const noexcept {127 return coroutine_handle<>::from_address(address());128 }129 130 // [coroutine.handle.observers], observers131 _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __handle_ != nullptr; }132 133 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool done() const {134 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(__is_suspended(), "done() can be called only on suspended coroutines");135 return __builtin_coro_done(__handle_);136 }137 138 // [coroutine.handle.resumption], resumption139 _LIBCPP_HIDE_FROM_ABI void operator()() const { resume(); }140 141 _LIBCPP_HIDE_FROM_ABI void resume() const {142 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(__is_suspended(), "resume() can be called only on suspended coroutines");143 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(!done(), "resume() has undefined behavior when the coroutine is done");144 __builtin_coro_resume(__handle_);145 }146 147 _LIBCPP_HIDE_FROM_ABI void destroy() const {148 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(__is_suspended(), "destroy() can be called only on suspended coroutines");149 __builtin_coro_destroy(__handle_);150 }151 152 // [coroutine.handle.promise], promise access153 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _Promise& promise() const {154 return *static_cast<_Promise*>(__builtin_coro_promise(this->__handle_, alignof(_Promise), false));155 }156 157private:158 _LIBCPP_HIDE_FROM_ABI bool __is_suspended() const {159 // FIXME actually implement a check for if the coro is suspended.160 return __handle_ != nullptr;161 }162 void* __handle_ = nullptr;163};164 165// [coroutine.handle.hash]166template <class _Tp>167struct hash<coroutine_handle<_Tp>> {168 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI size_t operator()(const coroutine_handle<_Tp>& __v) const noexcept {169 return hash<void*>()(__v.address());170 }171};172 173_LIBCPP_END_NAMESPACE_STD174 175#endif // _LIBCPP_STD_VER >= 20176 177#endif // _LIBCPP___COROUTINE_COROUTINE_HANDLE_H178