Re: [gpsd-dev] Updated docs on NTP segment management

[Gary E. Miller]

Yo Miroslav!

On Thu, 26 Feb 2015 11:44:22 +0100
Miroslav Lichvar <address@hidden> wrote:

> On Wed, Feb 25, 2015 at 11:03:15AM -0800, Hal Murray wrote:
> > address@hidden said:
> > > Yeah, I've already found some fields that I'd like to add to the
> > > protocol, but didn't do it to not break the compatibility. 
> > 
> > What did you have in mind?  I'd like to make sure we collect all
> > the good ideas while this discussion is going on.
> 
> Precision (this is in SHM but not chrony SOCK), dispersion, delay,
> root dispersion, root delay, stratum. This could be used for NTP
> sources as refclocks.

Sadly, the only one of those gpsd knows is precision.  We want it to
be read only on the NTP (client)  side.

> Also, it would be good to have some special value for unknown to not
> force the clients to put there some random value which would just make
> things worse.

We have the valid flag for that.  All or nothing.

> > Would it have made sense to use the dummy slots in the current
> > SHM?  (assume we could find a way to avoid collisions)
> 
> I think it would but how would it signal that the fields are set to
> not use some random garbage the client had on stack? Include a
> checksum?

The mode word can be used as a version.
 
RGDS
GARY
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