I have a blocking socket (at least it appears so in following code): And this is from log: Mar 6 10:42:04 tcpclient: fcntl ret=0, ret & O_NONBLOCK = 0 Mar 6 10:42:04 tcpclient: after select fcntl ret=0, ret & O_NONBLOCK = 0 Mar 6 10:42:14 tcpclient: authenticate: error on connect -> Operation now in progress It appears this is a