Thank you for your answer. You're right, with message member function, I get the "Already open" error. I don't really understand it, my source code is: void Server::receiving() { boost::system::error_code error; tcp::endpoint endp(tcp::v4(), 14242); acceptor = new tcp::acceptor(_io); acceptor->open(endp.protocol()); acceptor->set_option(tcp::acceptor::reuse_address(true)); acceptor->bind(endp); acceptor->listen(); _client = new tcp::socket(_io); _client->close(); acceptor->async_accept(*_client, boost::bind(&ipc::handle_accept, this, boost::asio::placeholders::error)); } What is "already open" ? _client ? It has just been allocated before calling async_accept. _io is properly initialized. If this error is about acceptor, how can I use it with async_accept ? I've seen http://www.boost.org/doc/libs/1_37_0/doc/html/boost_asio/reference/basic_soc... but i don't see any line where the listen port is set to acceptor. I'm sorry for my english which is not very good. Thank you ! ----- Mail original ----- De: "Igor R" À: boost-users@lists.boost.org Envoyé: Jeudi 10 Mars 2011 00:42:24 Objet: Re: [Boost-users] [ASIO] async_accept : Error m_val 1.

m_val = 1; m_cat = 0x00ab8d00 instance;  | [boost::asio::error::detail::misc_category] = {...}  | boost::noncopyable_::noncopyable = {...}  | __vfptr = 0x00a8bf18 const boost::asio::error::detail::misc_category::`vftable'

Use message() member function of error_code to see the error description. IIUC, in your case it should be "Already open", i.e. you're trying to accept new connection to a socket which was already open. _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users