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- //
- // impl/spawn.hpp
- // ~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
- //
- // Distributed under the Boost Software License, Version 1.0. (See accompanying
- // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- //
-
- #ifndef ASIO_IMPL_SPAWN_HPP
- #define ASIO_IMPL_SPAWN_HPP
-
- #if defined(_MSC_VER) && (_MSC_VER >= 1200)
- # pragma once
- #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
-
- #include "asio/detail/config.hpp"
- #include "asio/associated_allocator.hpp"
- #include "asio/associated_executor.hpp"
- #include "asio/async_result.hpp"
- #include "asio/bind_executor.hpp"
- #include "asio/detail/atomic_count.hpp"
- #include "asio/detail/handler_alloc_helpers.hpp"
- #include "asio/detail/handler_cont_helpers.hpp"
- #include "asio/detail/handler_invoke_helpers.hpp"
- #include "asio/detail/memory.hpp"
- #include "asio/detail/noncopyable.hpp"
- #include "asio/detail/type_traits.hpp"
- #include "asio/system_error.hpp"
-
- #include "asio/detail/push_options.hpp"
-
- namespace asio {
- namespace detail {
-
- template <typename Handler, typename T>
- class coro_handler
- {
- public:
- coro_handler(basic_yield_context<Handler> ctx)
- : coro_(ctx.coro_.lock()),
- ca_(ctx.ca_),
- handler_(ctx.handler_),
- ready_(0),
- ec_(ctx.ec_),
- value_(0)
- {
- }
-
- void operator()(T value)
- {
- *ec_ = asio::error_code();
- *value_ = ASIO_MOVE_CAST(T)(value);
- if (--*ready_ == 0)
- (*coro_)();
- }
-
- void operator()(asio::error_code ec, T value)
- {
- *ec_ = ec;
- *value_ = ASIO_MOVE_CAST(T)(value);
- if (--*ready_ == 0)
- (*coro_)();
- }
-
- //private:
- shared_ptr<typename basic_yield_context<Handler>::callee_type> coro_;
- typename basic_yield_context<Handler>::caller_type& ca_;
- Handler handler_;
- atomic_count* ready_;
- asio::error_code* ec_;
- T* value_;
- };
-
- template <typename Handler>
- class coro_handler<Handler, void>
- {
- public:
- coro_handler(basic_yield_context<Handler> ctx)
- : coro_(ctx.coro_.lock()),
- ca_(ctx.ca_),
- handler_(ctx.handler_),
- ready_(0),
- ec_(ctx.ec_)
- {
- }
-
- void operator()()
- {
- *ec_ = asio::error_code();
- if (--*ready_ == 0)
- (*coro_)();
- }
-
- void operator()(asio::error_code ec)
- {
- *ec_ = ec;
- if (--*ready_ == 0)
- (*coro_)();
- }
-
- //private:
- shared_ptr<typename basic_yield_context<Handler>::callee_type> coro_;
- typename basic_yield_context<Handler>::caller_type& ca_;
- Handler handler_;
- atomic_count* ready_;
- asio::error_code* ec_;
- };
-
- template <typename Handler, typename T>
- inline void* asio_handler_allocate(std::size_t size,
- coro_handler<Handler, T>* this_handler)
- {
- return asio_handler_alloc_helpers::allocate(
- size, this_handler->handler_);
- }
-
- template <typename Handler, typename T>
- inline void asio_handler_deallocate(void* pointer, std::size_t size,
- coro_handler<Handler, T>* this_handler)
- {
- asio_handler_alloc_helpers::deallocate(
- pointer, size, this_handler->handler_);
- }
-
- template <typename Handler, typename T>
- inline bool asio_handler_is_continuation(coro_handler<Handler, T>*)
- {
- return true;
- }
-
- template <typename Function, typename Handler, typename T>
- inline void asio_handler_invoke(Function& function,
- coro_handler<Handler, T>* this_handler)
- {
- asio_handler_invoke_helpers::invoke(
- function, this_handler->handler_);
- }
-
- template <typename Function, typename Handler, typename T>
- inline void asio_handler_invoke(const Function& function,
- coro_handler<Handler, T>* this_handler)
- {
- asio_handler_invoke_helpers::invoke(
- function, this_handler->handler_);
- }
-
- template <typename Handler, typename T>
- class coro_async_result
- {
- public:
- typedef coro_handler<Handler, T> completion_handler_type;
- typedef T return_type;
-
- explicit coro_async_result(completion_handler_type& h)
- : handler_(h),
- ca_(h.ca_),
- ready_(2)
- {
- h.ready_ = &ready_;
- out_ec_ = h.ec_;
- if (!out_ec_) h.ec_ = &ec_;
- h.value_ = &value_;
- }
-
- return_type get()
- {
- // Must not hold shared_ptr to coro while suspended.
- handler_.coro_.reset();
-
- if (--ready_ != 0)
- ca_();
- if (!out_ec_ && ec_) throw asio::system_error(ec_);
- return ASIO_MOVE_CAST(return_type)(value_);
- }
-
- private:
- completion_handler_type& handler_;
- typename basic_yield_context<Handler>::caller_type& ca_;
- atomic_count ready_;
- asio::error_code* out_ec_;
- asio::error_code ec_;
- return_type value_;
- };
-
- template <typename Handler>
- class coro_async_result<Handler, void>
- {
- public:
- typedef coro_handler<Handler, void> completion_handler_type;
- typedef void return_type;
-
- explicit coro_async_result(completion_handler_type& h)
- : handler_(h),
- ca_(h.ca_),
- ready_(2)
- {
- h.ready_ = &ready_;
- out_ec_ = h.ec_;
- if (!out_ec_) h.ec_ = &ec_;
- }
-
- void get()
- {
- // Must not hold shared_ptr to coro while suspended.
- handler_.coro_.reset();
-
- if (--ready_ != 0)
- ca_();
- if (!out_ec_ && ec_) throw asio::system_error(ec_);
- }
-
- private:
- completion_handler_type& handler_;
- typename basic_yield_context<Handler>::caller_type& ca_;
- atomic_count ready_;
- asio::error_code* out_ec_;
- asio::error_code ec_;
- };
-
- } // namespace detail
-
- #if !defined(GENERATING_DOCUMENTATION)
-
- template <typename Handler, typename ReturnType>
- class async_result<basic_yield_context<Handler>, ReturnType()>
- : public detail::coro_async_result<Handler, void>
- {
- public:
- explicit async_result(
- typename detail::coro_async_result<Handler,
- void>::completion_handler_type& h)
- : detail::coro_async_result<Handler, void>(h)
- {
- }
- };
-
- template <typename Handler, typename ReturnType, typename Arg1>
- class async_result<basic_yield_context<Handler>, ReturnType(Arg1)>
- : public detail::coro_async_result<Handler, typename decay<Arg1>::type>
- {
- public:
- explicit async_result(
- typename detail::coro_async_result<Handler,
- typename decay<Arg1>::type>::completion_handler_type& h)
- : detail::coro_async_result<Handler, typename decay<Arg1>::type>(h)
- {
- }
- };
-
- template <typename Handler, typename ReturnType>
- class async_result<basic_yield_context<Handler>,
- ReturnType(asio::error_code)>
- : public detail::coro_async_result<Handler, void>
- {
- public:
- explicit async_result(
- typename detail::coro_async_result<Handler,
- void>::completion_handler_type& h)
- : detail::coro_async_result<Handler, void>(h)
- {
- }
- };
-
- template <typename Handler, typename ReturnType, typename Arg2>
- class async_result<basic_yield_context<Handler>,
- ReturnType(asio::error_code, Arg2)>
- : public detail::coro_async_result<Handler, typename decay<Arg2>::type>
- {
- public:
- explicit async_result(
- typename detail::coro_async_result<Handler,
- typename decay<Arg2>::type>::completion_handler_type& h)
- : detail::coro_async_result<Handler, typename decay<Arg2>::type>(h)
- {
- }
- };
-
- template <typename Handler, typename T, typename Allocator>
- struct associated_allocator<detail::coro_handler<Handler, T>, Allocator>
- {
- typedef typename associated_allocator<Handler, Allocator>::type type;
-
- static type get(const detail::coro_handler<Handler, T>& h,
- const Allocator& a = Allocator()) ASIO_NOEXCEPT
- {
- return associated_allocator<Handler, Allocator>::get(h.handler_, a);
- }
- };
-
- template <typename Handler, typename T, typename Executor>
- struct associated_executor<detail::coro_handler<Handler, T>, Executor>
- {
- typedef typename associated_executor<Handler, Executor>::type type;
-
- static type get(const detail::coro_handler<Handler, T>& h,
- const Executor& ex = Executor()) ASIO_NOEXCEPT
- {
- return associated_executor<Handler, Executor>::get(h.handler_, ex);
- }
- };
-
- namespace detail {
-
- template <typename Handler, typename Function>
- struct spawn_data : private noncopyable
- {
- template <typename Hand, typename Func>
- spawn_data(ASIO_MOVE_ARG(Hand) handler,
- bool call_handler, ASIO_MOVE_ARG(Func) function)
- : handler_(ASIO_MOVE_CAST(Hand)(handler)),
- call_handler_(call_handler),
- function_(ASIO_MOVE_CAST(Func)(function))
- {
- }
-
- weak_ptr<typename basic_yield_context<Handler>::callee_type> coro_;
- Handler handler_;
- bool call_handler_;
- Function function_;
- };
-
- template <typename Handler, typename Function>
- struct coro_entry_point
- {
- void operator()(typename basic_yield_context<Handler>::caller_type& ca)
- {
- shared_ptr<spawn_data<Handler, Function> > data(data_);
- #if !defined(BOOST_COROUTINES_UNIDIRECT) && !defined(BOOST_COROUTINES_V2)
- ca(); // Yield until coroutine pointer has been initialised.
- #endif // !defined(BOOST_COROUTINES_UNIDIRECT) && !defined(BOOST_COROUTINES_V2)
- const basic_yield_context<Handler> yield(
- data->coro_, ca, data->handler_);
-
- (data->function_)(yield);
- if (data->call_handler_)
- (data->handler_)();
- }
-
- shared_ptr<spawn_data<Handler, Function> > data_;
- };
-
- template <typename Handler, typename Function>
- struct spawn_helper
- {
- void operator()()
- {
- typedef typename basic_yield_context<Handler>::callee_type callee_type;
- coro_entry_point<Handler, Function> entry_point = { data_ };
- shared_ptr<callee_type> coro(new callee_type(entry_point, attributes_));
- data_->coro_ = coro;
- (*coro)();
- }
-
- shared_ptr<spawn_data<Handler, Function> > data_;
- boost::coroutines::attributes attributes_;
- };
-
- template <typename Function, typename Handler, typename Function1>
- inline void asio_handler_invoke(Function& function,
- spawn_helper<Handler, Function1>* this_handler)
- {
- asio_handler_invoke_helpers::invoke(
- function, this_handler->data_->handler_);
- }
-
- template <typename Function, typename Handler, typename Function1>
- inline void asio_handler_invoke(const Function& function,
- spawn_helper<Handler, Function1>* this_handler)
- {
- asio_handler_invoke_helpers::invoke(
- function, this_handler->data_->handler_);
- }
-
- inline void default_spawn_handler() {}
-
- } // namespace detail
-
- template <typename Function>
- inline void spawn(ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes)
- {
- typedef typename decay<Function>::type function_type;
-
- typename associated_executor<function_type>::type ex(
- (get_associated_executor)(function));
-
- asio::spawn(ex, ASIO_MOVE_CAST(Function)(function), attributes);
- }
-
- template <typename Handler, typename Function>
- void spawn(ASIO_MOVE_ARG(Handler) handler,
- ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes,
- typename enable_if<!is_executor<typename decay<Handler>::type>::value &&
- !is_convertible<Handler&, execution_context&>::value>::type*)
- {
- typedef typename decay<Handler>::type handler_type;
- typedef typename decay<Function>::type function_type;
-
- typename associated_executor<handler_type>::type ex(
- (get_associated_executor)(handler));
-
- typename associated_allocator<handler_type>::type a(
- (get_associated_allocator)(handler));
-
- detail::spawn_helper<handler_type, function_type> helper;
- helper.data_.reset(
- new detail::spawn_data<handler_type, function_type>(
- ASIO_MOVE_CAST(Handler)(handler), true,
- ASIO_MOVE_CAST(Function)(function)));
- helper.attributes_ = attributes;
-
- ex.dispatch(helper, a);
- }
-
- template <typename Handler, typename Function>
- void spawn(basic_yield_context<Handler> ctx,
- ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes)
- {
- typedef typename decay<Function>::type function_type;
-
- Handler handler(ctx.handler_); // Explicit copy that might be moved from.
-
- typename associated_executor<Handler>::type ex(
- (get_associated_executor)(handler));
-
- typename associated_allocator<Handler>::type a(
- (get_associated_allocator)(handler));
-
- detail::spawn_helper<Handler, function_type> helper;
- helper.data_.reset(
- new detail::spawn_data<Handler, function_type>(
- ASIO_MOVE_CAST(Handler)(handler), false,
- ASIO_MOVE_CAST(Function)(function)));
- helper.attributes_ = attributes;
-
- ex.dispatch(helper, a);
- }
-
- template <typename Function, typename Executor>
- inline void spawn(const Executor& ex,
- ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes,
- typename enable_if<is_executor<Executor>::value>::type*)
- {
- asio::spawn(asio::strand<Executor>(ex),
- ASIO_MOVE_CAST(Function)(function), attributes);
- }
-
- template <typename Function, typename Executor>
- inline void spawn(const strand<Executor>& ex,
- ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes)
- {
- asio::spawn(asio::bind_executor(
- ex, &detail::default_spawn_handler),
- ASIO_MOVE_CAST(Function)(function), attributes);
- }
-
- template <typename Function>
- inline void spawn(const asio::io_context::strand& s,
- ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes)
- {
- asio::spawn(asio::bind_executor(
- s, &detail::default_spawn_handler),
- ASIO_MOVE_CAST(Function)(function), attributes);
- }
-
- template <typename Function, typename ExecutionContext>
- inline void spawn(ExecutionContext& ctx,
- ASIO_MOVE_ARG(Function) function,
- const boost::coroutines::attributes& attributes,
- typename enable_if<is_convertible<
- ExecutionContext&, execution_context&>::value>::type*)
- {
- asio::spawn(ctx.get_executor(),
- ASIO_MOVE_CAST(Function)(function), attributes);
- }
-
- #endif // !defined(GENERATING_DOCUMENTATION)
-
- } // namespace asio
-
- #include "asio/detail/pop_options.hpp"
-
- #endif // ASIO_IMPL_SPAWN_HPP
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