Re: Question on socket non block read

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Jeff,

Yes, I understand all of that.

The reason it works when you have data in the socket is because the 
recv() API will return the data instead of waiting for more.

A blocking socket will sit and wait for more data.  A non-blocking 
socket never sits and waits for more data.

This is NOT done within the nbrecv() routine... it must be done by you 
before you call nbrecv. The article explains how to put the socket into 
non-blocking mode.  If you haven't put it into nonblocking mode.  You 
will have the problem that you are reporting.

I understand what you are saying about moving the select before the recv 
-- personally, i think this is a poor solution. In my experience, your 
application will be more robust with the recv() first and using a 
non-blocking socket.

-SK

On 9/18/2015 1:09 PM, Jeff Young wrote:
> 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.