// // detail/wait_handler.hpp // ~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2022 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_WAIT_HANDLER_HPP #define BOOST_ASIO_DETAIL_WAIT_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/bind_handler.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/wait_op.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { namespace detail { template <typename Handler, typename IoExecutor> class wait_handler : public wait_op { public: BOOST_ASIO_DEFINE_HANDLER_PTR(wait_handler); wait_handler(Handler& h, const IoExecutor& io_ex) : wait_op(&wait_handler::do_complete), handler_(BOOST_ASIO_MOVE_CAST(Handler)(h)), work_(handler_, io_ex) { } 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. wait_handler* h(static_cast<wait_handler*>(base)); ptr p = { boost::asio::detail::addressof(h->handler_), h, h }; BOOST_ASIO_HANDLER_COMPLETION((*h)); // Take ownership of the operation's outstanding work. handler_work<Handler, IoExecutor> w( BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)( h->work_)); // 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. detail::binder1<Handler, boost::system::error_code> handler(h->handler_, h->ec_); p.h = boost::asio::detail::addressof(handler.handler_); p.reset(); // Make the upcall if required. if (owner) { fenced_block b(fenced_block::half); BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_)); w.complete(handler, handler.handler_); BOOST_ASIO_HANDLER_INVOCATION_END; } } private: Handler handler_; handler_work<Handler, IoExecutor> work_; }; } // namespace detail } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #endif // BOOST_ASIO_DETAIL_WAIT_HANDLER_HPP