Re: [lwip-users] snd_queuelen does not count the number of segments...

[Kieran Mansley]

On Mon, 2006-11-27 at 15:57 -0500, Tom Hennen wrote:
> Instead it counts the number of pbufs.  Why?
>  

Because the configuration limit is also specified in the number of
pbufs.  This allows people using it to have a much better estimate of
the amount of pbufs (and so memory) that can be used for the send queue,
which is important if you haven't got much memory (as per most lwIP
systems).

If we just counted segments, which can vary somewhat in size, you would
end up over-limiting the number of very small segments that can be
queued as your limit would have to be small enough to prevent lots of
large segments being queued as they would use up too much memory.

Perhaps counting the bytes would make most sense, but as our pbufs are
the resource it's trying to prevent being entirely consumed by the send
queue, I'm happy to leave it as it is.

Are you seeing a real problem, or just curious about why it's like that?

Kieran