Commit f9a78d598e refactored the code, but
in the process introduced a socket leak. When connect() is called on a
socket set to non-blocking mode, the returned error code is EINPROGRESS.
In that case, the code never initialises the ev structure and the socket
reference is lost. Given enough time (on my network about a day and a half)
this will eventually lead to a non-responsive server because the process
runs out of fds. Netstat will show an excessive number of sockets stuck in
CLOSE_WAIT state forever and ls /proc/<pid>/fd will confirm a lot of open
sockets.
Initialising the ev struct before a call to connect() ensures that the
socket reference is not lost. Verifying with netstat, one can see the
sockets in TIME_WAIT state for a brief period of time and /proc/<pid>/fd
shows a reasonable number of sockets being open.
