FreeTDS Development Group

[jklowden AT schemamania.org]

On Thu, Aug 18, 2011 at 10:51:21AM -0400, Brian Bruns wrote:
>
> I need to send a read/write request off to the server receive an
> EAGAIN and then go about my business and do a big select() with both
> the tds socket and other file descriptors and come back when there is
> something to handle.  I need to never, ever wait for the network.

Hi Brian, 

Stevens devotes a chapter each to non-blocking, asynch, and
signal-driven I/O.  They're all functionally equivalent.  I think
non-blocking is the best choice because it's the most portable.  

We see EAGAIN now when connecting.   We're already set to support the
"asynchronous" client library functions; we don't need FIOASYNC to do
that.   It's just a SMP.  

I wrote tds_select() to support timeouts and dbinterrupt().  It might
be trickier than you realize, because of the callbacks to the client
libraries and the fact that they don't deal with timeouts in the same
way.  It took me quite a while to straighten it all out.  

I think what you really want is a low-level interface to libtds?  

It's interesting -- and no coincidence -- that you and Frediano and I
all see need for changes in libtds.  I've been thinking about this for
quite some time, and I have some suggestions.  Let me start a new
thread for them, though.  

Regards, 

--jkl