Ludo Brands Fri Apr 26 19:25:52 CEST 2013 If your socket is in blocking mode and you don't want your thread to block, yes. Server or client, there is no difference. The same for send. When you have a small block to send that fits in the socket buffer and the socket buffer is empty, send will return immediately. But if you have more data to send, your second send will block until the first send is completed. The same select can be used to return when the recv buffer is not empty or the send buffer empty or when an exception occurs. See http://linux.die.net/man/2/select Ludo