1 // 2 // detail/resolve_endpoint_op.hpp 3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP 12 #define ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP 13 14 15 #include "asio/detail/config.hpp" 16 #include "asio/error.hpp" 17 #include "asio/io_service.hpp" 18 #include "asio/ip/basic_resolver_iterator.hpp" 19 #include "asio/detail/addressof.hpp" 20 #include "asio/detail/bind_handler.hpp" 21 #include "asio/detail/fenced_block.hpp" 22 #include "asio/detail/handler_alloc_helpers.hpp" 23 #include "asio/detail/handler_invoke_helpers.hpp" 24 #include "asio/detail/operation.hpp" 25 #include "asio/detail/socket_ops.hpp" 26 27 #include "asio/detail/push_options.hpp" 28 29 namespace asio { 30 namespace detail { 31 32 template <typename Protocol, typename Handler> 33 class resolve_endpoint_op : public operation 34 { 35 public: 36 ASIO_DEFINE_HANDLER_PTR(resolve_endpoint_op); 37 38 typedef typename Protocol::endpoint endpoint_type; 39 typedef asio::ip::basic_resolver_iterator<Protocol> iterator_type; 40 resolve_endpoint_op(socket_ops::weak_cancel_token_type cancel_token,const endpoint_type & endpoint,io_service_impl & ios,Handler & handler)41 resolve_endpoint_op(socket_ops::weak_cancel_token_type cancel_token, 42 const endpoint_type& endpoint, io_service_impl& ios, Handler& handler) 43 : operation(&resolve_endpoint_op::do_complete), 44 cancel_token_(cancel_token), 45 endpoint_(endpoint), 46 io_service_impl_(ios), 47 handler_(ASIO_MOVE_CAST(Handler)(handler)) 48 { 49 } 50 do_complete(io_service_impl * owner,operation * base,const asio::error_code &,std::size_t)51 static void do_complete(io_service_impl* owner, operation* base, 52 const asio::error_code& /*ec*/, 53 std::size_t /*bytes_transferred*/) 54 { 55 // Take ownership of the operation object. 56 resolve_endpoint_op* o(static_cast<resolve_endpoint_op*>(base)); 57 ptr p = { asio::detail::addressof(o->handler_), o, o }; 58 59 if (owner && owner != &o->io_service_impl_) 60 { 61 // The operation is being run on the worker io_service. Time to perform 62 // the resolver operation. 63 64 // Perform the blocking endpoint resolution operation. 65 char host_name[NI_MAXHOST]; 66 char service_name[NI_MAXSERV]; 67 socket_ops::background_getnameinfo(o->cancel_token_, o->endpoint_.data(), 68 o->endpoint_.size(), host_name, NI_MAXHOST, service_name, NI_MAXSERV, 69 o->endpoint_.protocol().type(), o->ec_); 70 o->iter_ = iterator_type::create(o->endpoint_, host_name, service_name); 71 72 // Pass operation back to main io_service for completion. 73 o->io_service_impl_.post_deferred_completion(o); 74 p.v = p.p = 0; 75 } 76 else 77 { 78 // The operation has been returned to the main io_service. The completion 79 // handler is ready to be delivered. 80 81 ASIO_HANDLER_COMPLETION((o)); 82 83 // Make a copy of the handler so that the memory can be deallocated 84 // before the upcall is made. Even if we're not about to make an upcall, 85 // a sub-object of the handler may be the true owner of the memory 86 // associated with the handler. Consequently, a local copy of the handler 87 // is required to ensure that any owning sub-object remains valid until 88 // after we have deallocated the memory here. 89 detail::binder2<Handler, asio::error_code, iterator_type> 90 handler(o->handler_, o->ec_, o->iter_); 91 p.h = asio::detail::addressof(handler.handler_); 92 p.reset(); 93 94 if (owner) 95 { 96 fenced_block b(fenced_block::half); 97 ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "...")); 98 asio_handler_invoke_helpers::invoke(handler, handler.handler_); 99 ASIO_HANDLER_INVOCATION_END; 100 } 101 } 102 } 103 104 private: 105 socket_ops::weak_cancel_token_type cancel_token_; 106 endpoint_type endpoint_; 107 io_service_impl& io_service_impl_; 108 Handler handler_; 109 asio::error_code ec_; 110 iterator_type iter_; 111 }; 112 113 } // namespace detail 114 } // namespace asio 115 116 #include "asio/detail/pop_options.hpp" 117 118 #endif // ASIO_DETAIL_RESOLVER_ENDPOINT_OP_HPP 119