Re: [lwip-users] Data waiting but no recv()

[Jonathan Larmour]

Josh Rothstein wrote:
> Is there a better alternative if I am using version 1.2.0.?

Upgrade to 1.3.0-RC1? :).

You could try and backport Frederic's patch:
https://savannah.nongnu.org/task/?func=detailitem&item_id=7421

Otherwise there's what I said in my first paragraph.

Although it's occurred to me, is this TCP or UDP? If it's TCP you should 
instead be tuning the value of the receiver TCP window (TCP_WND). This is 
already pretty low at 2k by default, but I guess you might have increased 
it by accident. You can only increase it if you can be sure you have 
enough memory for it! :)

Jifl

> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On Behalf Of
> Jonathan Larmour
> Sent: Monday, January 21, 2008 5:26 PM
> To: Mailing list for lwIP users
> Cc: 'Campanella, David'; 'John Zigrang'
> Subject: Re: [lwip-users] Data waiting but no recv()
>
> Josh Rothstein wrote:
>
> > What is the correct way to make sure that my stack does not lock up if I 
> > am receiving unexpected data over a connection?  Should I just poll() 
> > each time around the loop?  I cannot just place extra recv()s around the 
> > loop or else my task will block if no data is waiting.
>
>
> Theoretically, you can do it in a different task, use select() to wait for 
> multiple sockets when you would be blocked waiting for input anyway and/or 
> use non-blocking sockets if you were going to be doing a busy poll anyway.
>
> But the more efficient choice is to enable the LWIP_SO_RCVBUF option in 
> lwipopts.h and use setsockopt() to set it.
>
> Jifl


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