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- //
- // detail/completion_handler.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 BOOST_ASIO_DETAIL_COMPLETION_HANDLER_HPP
- #define BOOST_ASIO_DETAIL_COMPLETION_HANDLER_HPP
- #if defined(_MSC_VER) && (_MSC_VER >= 1200)
- # pragma once
- #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
- #include <boost/asio/detail/config.hpp>
- #include <boost/asio/detail/fenced_block.hpp>
- #include <boost/asio/detail/handler_alloc_helpers.hpp>
- #include <boost/asio/detail/handler_work.hpp>
- #include <boost/asio/detail/memory.hpp>
- #include <boost/asio/detail/operation.hpp>
- #include <boost/asio/detail/push_options.hpp>
- namespace boost {
- namespace asio {
- namespace detail {
- template <typename Handler>
- class completion_handler : public operation
- {
- public:
- BOOST_ASIO_DEFINE_HANDLER_PTR(completion_handler);
- completion_handler(Handler& h)
- : operation(&completion_handler::do_complete),
- handler_(BOOST_ASIO_MOVE_CAST(Handler)(h))
- {
- handler_work<Handler>::start(handler_);
- }
- static void do_complete(void* owner, operation* base,
- const boost::system::error_code& /*ec*/,
- std::size_t /*bytes_transferred*/)
- {
- // Take ownership of the handler object.
- completion_handler* h(static_cast<completion_handler*>(base));
- ptr p = { boost::asio::detail::addressof(h->handler_), h, h };
- handler_work<Handler> w(h->handler_);
- BOOST_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(BOOST_ASIO_MOVE_CAST(Handler)(h->handler_));
- p.h = boost::asio::detail::addressof(handler);
- p.reset();
- // Make the upcall if required.
- if (owner)
- {
- fenced_block b(fenced_block::half);
- BOOST_ASIO_HANDLER_INVOCATION_BEGIN(());
- w.complete(handler, handler);
- BOOST_ASIO_HANDLER_INVOCATION_END;
- }
- }
- private:
- Handler handler_;
- };
- } // namespace detail
- } // namespace asio
- } // namespace boost
- #include <boost/asio/detail/pop_options.hpp>
- #endif // BOOST_ASIO_DETAIL_COMPLETION_HANDLER_HPP
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