Re: [lwip-users] Required accuracy of timers

[Kieran Mansley]

On Wed, 2008-03-05 at 14:30 -0800, H. Peter Anvin wrote:
> H. Peter Anvin wrote:
> > Frédéric BERNON wrote:
> >> microseconds? Which ones? I thought most were in milliseconds. Which 
> >> lwIP release do you use?
> > 
> > Sorry, I might be mistaken.  I'm looking at 1.3.0.  Either way, the 
> > question still holds.
> > 
> 
> I guess I really should explain the background.
> 
> I'm looking at using this in a raw PC BIOS environment, where the only 
> *guaranteed* timer only has a 55 ms granularity.  There are ways to get 
> better resolution by going straight to the hardware, but PC hardware 
> being what it is (utter crap) that's a risky thing for trying to make 
> something that works on all platforms.

I would say 55ms would be fine for running the stack's timers.  However,
the application using the stack might be (for example) using the socket
API and specifying much smaller timeouts than 55ms.  There's a chance it
would get upset if it didn't behave as it expected.  So, if you know the
application won't mind, I think you'll probably be OK.

Kieran