| // -*- C++ -*- |
| //===----------------------------- coroutine -----------------------------===// |
| // |
| // 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_EXPERIMENTAL_COROUTINE |
| #define _LIBCPP_EXPERIMENTAL_COROUTINE |
| |
| /** |
| experimental/coroutine synopsis |
| |
| // C++next |
| |
| namespace std { |
| namespace experimental { |
| inline namespace coroutines_v1 { |
| |
| // 18.11.1 coroutine traits |
| template <typename R, typename... ArgTypes> |
| class coroutine_traits; |
| // 18.11.2 coroutine handle |
| template <typename Promise = void> |
| class coroutine_handle; |
| // 18.11.2.7 comparison operators: |
| bool operator==(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT; |
| bool operator!=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT; |
| bool operator<(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT; |
| bool operator<=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT; |
| bool operator>=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT; |
| bool operator>(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT; |
| // 18.11.3 trivial awaitables |
| struct suspend_never; |
| struct suspend_always; |
| // 18.11.2.8 hash support: |
| template <class T> struct hash; |
| template <class P> struct hash<coroutine_handle<P>>; |
| |
| } // namespace coroutines_v1 |
| } // namespace experimental |
| } // namespace std |
| |
| */ |
| |
| #include <experimental/__config> |
| #include <new> |
| #include <type_traits> |
| #include <functional> |
| #include <memory> // for hash<T*> |
| #include <cstddef> |
| #include <__debug> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| #ifdef _LIBCPP_HAS_NO_COROUTINES |
| # if defined(_LIBCPP_WARNING) |
| _LIBCPP_WARNING("<experimental/coroutine> cannot be used with this compiler") |
| # else |
| # warning <experimental/coroutine> cannot be used with this compiler |
| # endif |
| #endif |
| |
| #ifndef _LIBCPP_HAS_NO_COROUTINES |
| |
| _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_COROUTINES |
| |
| template <class _Tp, class = void> |
| struct __coroutine_traits_sfinae {}; |
| |
| template <class _Tp> |
| struct __coroutine_traits_sfinae< |
| _Tp, typename __void_t<typename _Tp::promise_type>::type> |
| { |
| using promise_type = typename _Tp::promise_type; |
| }; |
| |
| template <typename _Ret, typename... _Args> |
| struct coroutine_traits |
| : public __coroutine_traits_sfinae<_Ret> |
| { |
| }; |
| |
| template <typename _Promise = void> |
| class _LIBCPP_TEMPLATE_VIS coroutine_handle; |
| |
| template <> |
| class _LIBCPP_TEMPLATE_VIS coroutine_handle<void> { |
| public: |
| _LIBCPP_INLINE_VISIBILITY |
| _LIBCPP_CONSTEXPR coroutine_handle() _NOEXCEPT : __handle_(nullptr) {} |
| |
| _LIBCPP_INLINE_VISIBILITY |
| _LIBCPP_CONSTEXPR coroutine_handle(nullptr_t) _NOEXCEPT : __handle_(nullptr) {} |
| |
| _LIBCPP_INLINE_VISIBILITY |
| coroutine_handle& operator=(nullptr_t) _NOEXCEPT { |
| __handle_ = nullptr; |
| return *this; |
| } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| _LIBCPP_CONSTEXPR void* address() const _NOEXCEPT { return __handle_; } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| _LIBCPP_CONSTEXPR explicit operator bool() const _NOEXCEPT { return __handle_; } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| void operator()() { resume(); } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| void resume() { |
| _LIBCPP_ASSERT(__is_suspended(), |
| "resume() can only be called on suspended coroutines"); |
| _LIBCPP_ASSERT(!done(), |
| "resume() has undefined behavior when the coroutine is done"); |
| __builtin_coro_resume(__handle_); |
| } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| void destroy() { |
| _LIBCPP_ASSERT(__is_suspended(), |
| "destroy() can only be called on suspended coroutines"); |
| __builtin_coro_destroy(__handle_); |
| } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| bool done() const { |
| _LIBCPP_ASSERT(__is_suspended(), |
| "done() can only be called on suspended coroutines"); |
| return __builtin_coro_done(__handle_); |
| } |
| |
| public: |
| _LIBCPP_INLINE_VISIBILITY |
| static coroutine_handle from_address(void* __addr) _NOEXCEPT { |
| coroutine_handle __tmp; |
| __tmp.__handle_ = __addr; |
| return __tmp; |
| } |
| |
| // FIXME: Should from_address(nullptr) be allowed? |
| _LIBCPP_INLINE_VISIBILITY |
| static coroutine_handle from_address(nullptr_t) _NOEXCEPT { |
| return coroutine_handle(nullptr); |
| } |
| |
| template <class _Tp, bool _CallIsValid = false> |
| static coroutine_handle from_address(_Tp*) { |
| static_assert(_CallIsValid, |
| "coroutine_handle<void>::from_address cannot be called with " |
| "non-void pointers"); |
| } |
| |
| private: |
| bool __is_suspended() const _NOEXCEPT { |
| // FIXME actually implement a check for if the coro is suspended. |
| return __handle_; |
| } |
| |
| template <class _PromiseT> friend class coroutine_handle; |
| void* __handle_; |
| }; |
| |
| // 18.11.2.7 comparison operators: |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool operator==(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT { |
| return __x.address() == __y.address(); |
| } |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool operator!=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT { |
| return !(__x == __y); |
| } |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool operator<(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT { |
| return less<void*>()(__x.address(), __y.address()); |
| } |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool operator>(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT { |
| return __y < __x; |
| } |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool operator<=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT { |
| return !(__x > __y); |
| } |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool operator>=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT { |
| return !(__x < __y); |
| } |
| |
| template <typename _Promise> |
| class _LIBCPP_TEMPLATE_VIS coroutine_handle : public coroutine_handle<> { |
| using _Base = coroutine_handle<>; |
| public: |
| #ifndef _LIBCPP_CXX03_LANG |
| // 18.11.2.1 construct/reset |
| using coroutine_handle<>::coroutine_handle; |
| #else |
| _LIBCPP_INLINE_VISIBILITY coroutine_handle() _NOEXCEPT : _Base() {} |
| _LIBCPP_INLINE_VISIBILITY coroutine_handle(nullptr_t) _NOEXCEPT : _Base(nullptr) {} |
| #endif |
| _LIBCPP_INLINE_VISIBILITY |
| coroutine_handle& operator=(nullptr_t) _NOEXCEPT { |
| _Base::operator=(nullptr); |
| return *this; |
| } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| _Promise& promise() const { |
| return *static_cast<_Promise*>( |
| __builtin_coro_promise(this->__handle_, _LIBCPP_ALIGNOF(_Promise), false)); |
| } |
| |
| public: |
| _LIBCPP_INLINE_VISIBILITY |
| static coroutine_handle from_address(void* __addr) _NOEXCEPT { |
| coroutine_handle __tmp; |
| __tmp.__handle_ = __addr; |
| return __tmp; |
| } |
| |
| // NOTE: this overload isn't required by the standard but is needed so |
| // the deleted _Promise* overload doesn't make from_address(nullptr) |
| // ambiguous. |
| // FIXME: should from_address work with nullptr? |
| _LIBCPP_INLINE_VISIBILITY |
| static coroutine_handle from_address(nullptr_t) _NOEXCEPT { |
| return coroutine_handle(nullptr); |
| } |
| |
| template <class _Tp, bool _CallIsValid = false> |
| static coroutine_handle from_address(_Tp*) { |
| static_assert(_CallIsValid, |
| "coroutine_handle<promise_type>::from_address cannot be called with " |
| "non-void pointers"); |
| } |
| |
| template <bool _CallIsValid = false> |
| static coroutine_handle from_address(_Promise*) { |
| static_assert(_CallIsValid, |
| "coroutine_handle<promise_type>::from_address cannot be used with " |
| "pointers to the coroutine's promise type; use 'from_promise' instead"); |
| } |
| |
| _LIBCPP_INLINE_VISIBILITY |
| static coroutine_handle from_promise(_Promise& __promise) _NOEXCEPT { |
| typedef typename remove_cv<_Promise>::type _RawPromise; |
| coroutine_handle __tmp; |
| __tmp.__handle_ = __builtin_coro_promise( |
| _VSTD::addressof(const_cast<_RawPromise&>(__promise)), |
| _LIBCPP_ALIGNOF(_Promise), true); |
| return __tmp; |
| } |
| }; |
| |
| #if __has_builtin(__builtin_coro_noop) |
| struct noop_coroutine_promise {}; |
| |
| template <> |
| class _LIBCPP_TEMPLATE_VIS coroutine_handle<noop_coroutine_promise> |
| : public coroutine_handle<> { |
| using _Base = coroutine_handle<>; |
| using _Promise = noop_coroutine_promise; |
| public: |
| |
| _LIBCPP_INLINE_VISIBILITY |
| _Promise& promise() const { |
| return *static_cast<_Promise*>( |
| __builtin_coro_promise(this->__handle_, _LIBCPP_ALIGNOF(_Promise), false)); |
| } |
| |
| _LIBCPP_CONSTEXPR explicit operator bool() const _NOEXCEPT { return true; } |
| _LIBCPP_CONSTEXPR bool done() const _NOEXCEPT { return false; } |
| |
| _LIBCPP_CONSTEXPR_AFTER_CXX17 void operator()() const _NOEXCEPT {} |
| _LIBCPP_CONSTEXPR_AFTER_CXX17 void resume() const _NOEXCEPT {} |
| _LIBCPP_CONSTEXPR_AFTER_CXX17 void destroy() const _NOEXCEPT {} |
| |
| private: |
| _LIBCPP_INLINE_VISIBILITY |
| friend coroutine_handle<noop_coroutine_promise> noop_coroutine() _NOEXCEPT; |
| |
| _LIBCPP_INLINE_VISIBILITY coroutine_handle() _NOEXCEPT { |
| this->__handle_ = __builtin_coro_noop(); |
| } |
| }; |
| |
| using noop_coroutine_handle = coroutine_handle<noop_coroutine_promise>; |
| |
| inline _LIBCPP_INLINE_VISIBILITY |
| noop_coroutine_handle noop_coroutine() _NOEXCEPT { |
| return noop_coroutine_handle(); |
| } |
| #endif // __has_builtin(__builtin_coro_noop) |
| |
| struct suspend_never { |
| _LIBCPP_INLINE_VISIBILITY |
| bool await_ready() const _NOEXCEPT { return true; } |
| _LIBCPP_INLINE_VISIBILITY |
| void await_suspend(coroutine_handle<>) const _NOEXCEPT {} |
| _LIBCPP_INLINE_VISIBILITY |
| void await_resume() const _NOEXCEPT {} |
| }; |
| |
| struct suspend_always { |
| _LIBCPP_INLINE_VISIBILITY |
| bool await_ready() const _NOEXCEPT { return false; } |
| _LIBCPP_INLINE_VISIBILITY |
| void await_suspend(coroutine_handle<>) const _NOEXCEPT {} |
| _LIBCPP_INLINE_VISIBILITY |
| void await_resume() const _NOEXCEPT {} |
| }; |
| |
| _LIBCPP_END_NAMESPACE_EXPERIMENTAL_COROUTINES |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _Tp> |
| struct hash<_VSTD_CORO::coroutine_handle<_Tp> > { |
| using __arg_type = _VSTD_CORO::coroutine_handle<_Tp>; |
| _LIBCPP_INLINE_VISIBILITY |
| size_t operator()(__arg_type const& __v) const _NOEXCEPT |
| {return hash<void*>()(__v.address());} |
| }; |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // !defined(_LIBCPP_HAS_NO_COROUTINES) |
| |
| #endif /* _LIBCPP_EXPERIMENTAL_COROUTINE */ |