On Wed, 2007-08-29 at 16:32 +0200, Jan Kiszka wrote:
> Markus Osterried (BA/EDD) wrote:
> > Hi,
> > 
> > it seems that in the RTDM API, all the timeout functions which use
> > nanosecs_rel_t have a strange behaviour.
> > The timeout in nanoseconds is converted to ticks and the number of ticks
> > is rounded down. So when we want to wait e.g. 500000 nanoseconds and the
> > timertick is 1 ms, xnpod_ns2ticks() rounds down to 0. But 0 is the
> > special value RTDM_TIMEOUT_INFINITE, so we wait forever. I use Xenomai
> > 2.3.1, but I think it's basically the same in trunk.
> It should even impact other skins as well when in tick-based timing
> mode. I would bet more users of xnpod_ns2ticks() may have overseen this
> rounding issue - like RTDM did.

Other skins may only mean POSIX and native, since the other ones only
deal with ticks.

> > Wouldn't it be better to round up the ticks instead of round it down?
> Hmm, probably. Mind to work out a patch for xnpod_ticks2ns()?
> What do others think about this issue? Can/should we change the rounding
> behaviour at nucleus level?

Clearly not. You don't change the core rounding policy for fixing
shortcomings in the higher levels, especially to fix invalid application
requests. I do want to be able to round down at nucleus level, which I
would not be able to do anymore with a rounding up policy at core level.
This change belongs to the skin which wants this behaviour.

> Thanks for reporting,
> Jan
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