// // detail/resolve_endpoint_op.hpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2018 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_RESOLVER_ENDPOINT_OP_HPP #define BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include #include #include #include #include #include #include #include #include #include #include #include namespace boost { namespace asio { namespace detail { template class resolve_endpoint_op : public resolve_op { public: BOOST_ASIO_DEFINE_HANDLER_PTR(resolve_endpoint_op); typedef typename Protocol::endpoint endpoint_type; typedef boost::asio::ip::basic_resolver_results results_type; resolve_endpoint_op(socket_ops::weak_cancel_token_type cancel_token, const endpoint_type& endpoint, io_context_impl& ioc, Handler& handler) : resolve_op(&resolve_endpoint_op::do_complete), cancel_token_(cancel_token), endpoint_(endpoint), io_context_impl_(ioc), handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)) { handler_work::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 operation object. resolve_endpoint_op* o(static_cast(base)); ptr p = { boost::asio::detail::addressof(o->handler_), o, o }; handler_work w(o->handler_); if (owner && owner != &o->io_context_impl_) { // The operation is being run on the worker io_context. Time to perform // the resolver operation. // Perform the blocking endpoint resolution operation. char host_name[NI_MAXHOST]; char service_name[NI_MAXSERV]; socket_ops::background_getnameinfo(o->cancel_token_, o->endpoint_.data(), o->endpoint_.size(), host_name, NI_MAXHOST, service_name, NI_MAXSERV, o->endpoint_.protocol().type(), o->ec_); o->results_ = results_type::create(o->endpoint_, host_name, service_name); // Pass operation back to main io_context for completion. o->io_context_impl_.post_deferred_completion(o); p.v = p.p = 0; } else { // The operation has been returned to the main io_context. The completion // handler is ready to be delivered. BOOST_ASIO_HANDLER_COMPLETION((*o)); // 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(o->handler_, o->ec_, o->results_); p.h = boost::asio::detail::addressof(handler.handler_); p.reset(); 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: socket_ops::weak_cancel_token_type cancel_token_; endpoint_type endpoint_; io_context_impl& io_context_impl_; Handler handler_; results_type results_; }; } // namespace detail } // namespace asio } // namespace boost #include #endif // BOOST_ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP