Re: [gpsd-dev] [PATCH] [RFC] gpsmon: add PPS monitoring at -D2 debug level

[Eric S. Raymond]

Beat Bolli <address@hidden>:
> This is a request for comment for adding PPS output to gpsmon, as seen
> on Eric's TODO list.
> 
> The patch works, but has two issues, IMO. Both are marked with "FIXME"
> in the source:
> 
> - I'm not sure about updating device->last_fixtime where it is now. It
>   works but maybe there's a better place?

Probably this should be done somewhere in the generic PPS reporting loop
itself, rather that requiring callers to manage it.  I'll look into it.
 
> - An allocated SHM segment has to be faked, otherwise
>   pps_thread_activate() won't even start the thread.

Yeah, that's a structural bug.  It reveals that I haven't decoupled 
the generic PPS stuff from the management of the SHM segment quite
enough yet.  I will definitely fix this.

> A different issue is whether it's OK to output the PPS messages only at
> -D2. Should they be visible at any debug level?

Yes.  See my reply to Greg Troxel.

I actually tried implementing this but failed because I didn't realize
there was still a bad cohesion to the SHM allocation.  Good work noticing
that.
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>