Re: Select with nonblocking connects

[Thomas Pfaff <tpfaff at gmx dot net>]

On Fri, 5 Jul 2002, Corinna Vinschen wrote:

> On Fri, Jul 05, 2002 at 03:20:19PM +0200, Thomas Pfaff wrote:
> >
> > I guess the easiest way is to add a flag in fhandler_socket that is set
> > when a connect is in progress. If it is set then add the sock handle to
> > exceptfds as well. After select returns check the exceptfds, if the socket
> > is signaled set it in writefds too. In UNIX you have to check the SO_ERROR
> > sockopt to know if the connect has succeded or failed, but winsock sets is as
> > well. Now clear the in_progress flag.
> >
> > For listening sockets i see no difference.
>
> Huh?  The problem is the same as long as neither connect() nor listen()
> have been called, nor a non-blocking connect() has succeeded.  In either
> case, the WinSock select() blocks if the SOCKET is given in write_fd,
> while the Linux select() returns with the fd set in write_fd.
> The difference is just the SO_ERROR value which is 0 as long as neither
> connect() nor listen() have been called, resp EINPROGRESS in case of a
> not finshed connect().
>
> I'm not talking about a listening socket.  I'm talking about a socket in
> neither listening nor connected state.

Sorry for the mistake. I could not imagine that someone call select with a
socket that is neither connected nor listening nor pending.
What is he expecting to get ?

Thomas