Dear everybody, I have a problem using asio. My client/server application requires only synchronous communication. So, using the examples for synchro from the boost homepage, I have set up two procedures to send and receive data. Their code is as follows: void vReceive(tcp::socket & socket, std::string & szDest){ char szTmp_Buf [BUF_LEN + 1]; szDest = ""; std::cout << "Entering vReceive . . ." << std::endl; for (;;){ char szBuf [BUF_LEN]; boost::system::error_code error; uInt uiBytes_Recv = socket.read_some(boost::asio::buffer(szBuf), error); std::cout << " Read " << uiBytes_Recv << " bytes" << std::endl; if (error == boost::asio::error::eof) break; // Connection closed cleanly by peer. else if (error) throw boost::system::system_error(error); // Some other error. memcpy((void*) szTmp_Buf, (void*) szBuf, uiBytes_Recv ); szTmp_Buf[ uiBytes_Recv ] = '\0'; szDest += szTmp_Buf; }; std::cout << "Received" << szDest << std::endl; std::cout << "Leaving vReceive . . ." << std::endl << std::endl; }; void vSend(tcp::socket & socket, std::string & szSrc){ std::cout << "Entering vSend . . . " << std::endl; std::cout << "Sending " << szSrc << std::endl; boost::system::error_code ignored_error; boost::asio::write(socket, boost::asio::buffer(szSrc), boost::asio::transfer_all(), ignored_error); std::cout << "Leaving vSend . . . " << std::endl << std::endl; }; These procedures are just wrappers for the lines of code extracted from the boost examples. In my test applications, the client calls vReceive(socket, szDate); vSend(socket, std::string("Chop Suey!") ); vReceive(socket, szDate); vSend(socket, std::string("Halo")); and the server calls vSend(socket, message); vReceive(socket, szReceived); vSend(socket, message); vReceive(socket, szReceived); just to test the functionality. The problem is that both applications freeze after the first information exchange, as I have depicted on the following picture ( http://eubie.sweb.cz/asio_problem.JPG ). It seems that vReceive() procedure on the client side doesn´t finish while vSend() finishes on the server side. So, does anybody have any idea, what might be wrong? Just in case someone wanted to replicate the problem, I uploaded the complete sources to http://eubie.sweb.cz/asio_problem.rar file. Thank you all in advance, Daniel.