| // |
| // impl/defer.hpp |
| // ~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2020 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_DEFER_HPP |
| #define ASIO_IMPL_DEFER_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/detail/work_dispatcher.hpp" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| |
| class initiate_defer |
| { |
| public: |
| template <typename CompletionHandler> |
| void operator()(ASIO_MOVE_ARG(CompletionHandler) handler) const |
| { |
| typedef typename decay<CompletionHandler>::type handler_t; |
| |
| typename handler_t::executor_type ex(handler.get_executor()); |
| |
| typename associated_allocator<handler_t>::type alloc( |
| (get_associated_allocator)(handler)); |
| |
| ex.defer(ASIO_MOVE_CAST(CompletionHandler)(handler), alloc); |
| } |
| }; |
| |
| template <typename Executor> |
| class initiate_defer_with_executor |
| { |
| public: |
| typedef Executor executor_type; |
| |
| explicit initiate_defer_with_executor(const Executor& ex) |
| : io_ex_(ex) |
| { |
| } |
| |
| executor_type get_executor() const ASIO_NOEXCEPT |
| { |
| return io_ex_; |
| } |
| |
| template <typename CompletionHandler> |
| void operator()(ASIO_MOVE_ARG(CompletionHandler) handler) const |
| { |
| typedef typename decay<CompletionHandler>::type handler_t; |
| |
| typedef typename associated_executor< |
| handler_t, Executor>::type handler_ex_t; |
| handler_ex_t handler_ex((get_associated_executor)(handler, io_ex_)); |
| |
| typename associated_allocator<handler_t>::type alloc( |
| (get_associated_allocator)(handler)); |
| |
| if (this->is_same_executor(io_ex_, handler_ex)) |
| { |
| io_ex_.defer(ASIO_MOVE_CAST(CompletionHandler)(handler), alloc); |
| } |
| else |
| { |
| io_ex_.defer(detail::work_dispatcher<handler_t, handler_ex_t>( |
| ASIO_MOVE_CAST(CompletionHandler)(handler), handler_ex), alloc); |
| } |
| } |
| |
| private: |
| template <typename T, typename U> |
| bool is_same_executor(const T&, const U&) const |
| { |
| return false; |
| } |
| |
| template <typename T> |
| bool is_same_executor(const T& a, const T& b) const |
| { |
| return a == b; |
| } |
| |
| Executor io_ex_; |
| }; |
| |
| } // namespace detail |
| |
| template <ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken> |
| ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) defer( |
| ASIO_MOVE_ARG(CompletionToken) token) |
| { |
| return async_initiate<CompletionToken, void()>( |
| detail::initiate_defer(), token); |
| } |
| |
| template <typename Executor, |
| ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken> |
| ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) defer( |
| const Executor& ex, ASIO_MOVE_ARG(CompletionToken) token, |
| typename enable_if<is_executor<Executor>::value>::type*) |
| { |
| return async_initiate<CompletionToken, void()>( |
| detail::initiate_defer_with_executor<Executor>(ex), token); |
| } |
| |
| template <typename ExecutionContext, |
| ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken> |
| inline ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) defer( |
| ExecutionContext& ctx, ASIO_MOVE_ARG(CompletionToken) token, |
| typename enable_if<is_convertible< |
| ExecutionContext&, execution_context&>::value>::type*) |
| { |
| return (defer)(ctx.get_executor(), |
| ASIO_MOVE_CAST(CompletionToken)(token)); |
| } |
| |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // ASIO_IMPL_DEFER_HPP |