Re: Question on socket non block read

Scott,
I was using the nbrecv procedure from the article
http://iprodeveloper.com/rpg-programming/timeouts-sockets.
I copied the code from there and was using that version.
As long as the socket contained data, there was no problem.
As soon as there was no data available, the recv() function just hung up.
I changed my procedure to move the recv() after the select() and now it is
working fine.


Jeff Young
Sr. Programmer Analyst

On Fri, Sep 18, 2015 at 1:23 PM, Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>
wrote:

Brad,

It sounds to me like you & I have had the opposite experiences. I've
never seen recv/send hang on a non-blocking socket. (Blocking, yes...
that's a different story.)

But I've definitely had problems with select() waiting for data when
there's already data available. As I mentioned before, this is a
documented/expected situation with SSL sockets. Though, I've seen it on
non-SSL sockets, too, though I suspect that was a bug that was fixed years
back.

-SK


On 9/18/2015 10:24 AM, Bradley Stone wrote:

Scott,

I personally use select() before reads and writes to check for data that's
ready as well for a timeout from a dropped/disconnected socket.

I added that years ago to my sockets applications... I'm not exactly sure
why but I seem to recall having issues with bad connections where
read/write would just hang.

Brad
www.bvstools.com

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