| // |
| // detail/completion_handler.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2016 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_DETAIL_COMPLETION_HANDLER_HPP |
| #define ASIO_DETAIL_COMPLETION_HANDLER_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include "asio/detail/config.hpp" |
| #include "asio/detail/fenced_block.hpp" |
| #include "asio/detail/handler_alloc_helpers.hpp" |
| #include "asio/detail/handler_work.hpp" |
| #include "asio/detail/memory.hpp" |
| #include "asio/detail/operation.hpp" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| |
| template <typename Handler> |
| class completion_handler : public operation |
| { |
| public: |
| ASIO_DEFINE_HANDLER_PTR(completion_handler); |
| |
| completion_handler(Handler& h) |
| : operation(&completion_handler::do_complete), |
| handler_(ASIO_MOVE_CAST(Handler)(h)) |
| { |
| handler_work<Handler>::start(handler_); |
| } |
| |
| static void do_complete(void* owner, operation* base, |
| const asio::error_code& /*ec*/, |
| std::size_t /*bytes_transferred*/) |
| { |
| // Take ownership of the handler object. |
| completion_handler* h(static_cast<completion_handler*>(base)); |
| ptr p = { asio::detail::addressof(h->handler_), h, h }; |
| handler_work<Handler> w(h->handler_); |
| |
| ASIO_HANDLER_COMPLETION((*h)); |
| |
| // Make a copy of the handler so that the memory can be deallocated before |
| // the upcall is made. Even if we're not about to make an upcall, a |
| // sub-object of the handler may be the true owner of the memory associated |
| // with the handler. Consequently, a local copy of the handler is required |
| // to ensure that any owning sub-object remains valid until after we have |
| // deallocated the memory here. |
| Handler handler(ASIO_MOVE_CAST(Handler)(h->handler_)); |
| p.h = asio::detail::addressof(handler); |
| p.reset(); |
| |
| // Make the upcall if required. |
| if (owner) |
| { |
| fenced_block b(fenced_block::half); |
| ASIO_HANDLER_INVOCATION_BEGIN(()); |
| w.complete(handler, handler); |
| ASIO_HANDLER_INVOCATION_END; |
| } |
| } |
| |
| private: |
| Handler handler_; |
| }; |
| |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // ASIO_DETAIL_COMPLETION_HANDLER_HPP |