// // detail/reactive_null_buffers_op.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_REACTIVE_NULL_BUFFERS_OP_HPP #define BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_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_invoke_helpers.hpp> #include <boost/asio/detail/handler_work.hpp> #include <boost/asio/detail/memory.hpp> #include <boost/asio/detail/reactor_op.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { namespace detail { template <typename Handler, typename IoExecutor> class reactive_null_buffers_op : public reactor_op { public: BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_null_buffers_op); reactive_null_buffers_op(const boost::system::error_code& success_ec, Handler& handler, const IoExecutor& io_ex) : reactor_op(success_ec, &reactive_null_buffers_op::do_perform, &reactive_null_buffers_op::do_complete), handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)), work_(handler_, io_ex) { } static status do_perform(reactor_op*) { return done; } 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. reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base)); ptr p = { boost::asio::detail::addressof(o->handler_), o, o }; BOOST_ASIO_HANDLER_COMPLETION((*o)); // Take ownership of the operation's outstanding work. handler_work<Handler, IoExecutor> w( BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)( o->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::binder2<Handler, boost::system::error_code, std::size_t> handler(o->handler_, o->ec_, o->bytes_transferred_); 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_, handler.arg2_)); 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_REACTIVE_NULL_BUFFERS_OP_HPP