I am using asio asynchronically. I have: void tcp_session::start_read() { // Set a deadline for the read operation. // input_deadline_.expires_from_now(boost::posix_time::seconds(30)); // input_deadline_.expires_at(boost::posix_time::pos_infin); // Start an asynchronous operation to read a newline-delimited message. boost::asio::async_read_until(socket(), input_buffer_, '\n', boost::bind(&tcp_session::handle_read, shared_from_this(), boost::asio::placeholders::error)); } void tcp_session::handle_read(const boost::system::error_code& ec) { if (stopped()) return; if (!ec) { // Extract the newline-delimited message from the buffer. std::string msg; std::istream is(&input_buffer_); is.exceptions( std::ifstream::failbit | std::ifstream::badbit | std::ifstream::eofbit ); try { while ( std::getline(is, msg) ) { // parse msg here (gets truncated to last 256 chars or so) std::cerr << msg << std::endl; } } catch ( const std::ios_base::failure& e ) { std::cerr << "getline failure " << e.what() << std::endl; } } My problem is that I am seeing messages that are not a full line, but a truncation of the line, as if a buffer gets full with 256 characters. I am unsure what I am doing wrong. I get a getline failure saying basic_ios::clear.