connect() to localhost non-blocking.

[Patrick Mau]

Hallo all,

I wrote a little test program to do some poll() benchmarks.
I changed the host address to localhost and observed that
connect() always returns EINPROGRESS when used with non-blocking
sockets.

EINPROGRESS
 The socket is non-blocking and the connection cannot be completed
 immediately. It is possible to select(2) or poll(2) for completion by
 selecting the socket for writing.

So my question is:

What is meant by 'cannot be completed immediately' ?
I thought that connections to localhost would complete
without any delay when the application listens ?

thanks for your answers,
Patrick