Re: [gpsd-dev] ✘GPSD_API

[Fred Wright]

On Thu, 14 Apr 2016, Gary E. Miller wrote:

> Thanks for the confirmation.  Now I am hitting my head on a wall as
> when I checn gpsdata_t my scons check fails.
>
> Processing test/daemon/passthrough.log
> gpsd:ERROR: shmget(0x47505345, 9512, 0666) for SHM export f ailed: Invalid 
> argument
>
> Which usually means mismatched shmget() sizes, but I can't figure out
> why the test harness is using the old sizeof(shmexport_t) and not the
> new one.  Deleting all system gpsd libs and starting from a fresh
> git clone, plus the one cchange, is no help.

Do you have an ntpd running with a SHM source enabled?  BTW, changing the
size without breaking NTP might be an issue.

Also, if by "fresh git clone" you mean re-cloning the repo, that's almost
certainly unnecessary since "git clean -dxf" gives you essentially the
same result.

On Thu, 14 Apr 2016, Gary E. Miller wrote:

> I have been digging into the change, and found that _used and _visible
> are not even used by the gpsd clients!  Instead those numbers are
> recreated in the json client by counting up objects in the sats array.
>
> I like that strategy, you know the actual counts will always match
> the totals.  Carrying core data, and derived data, often leads to
> discrepancies.

Well, a count that actually matches the data being delivered might be
useful to an application that wants to know how big a buffer to allocate
before scanning the data.  Or to an application that only wants to report
the counts and doesn't care about the individual items at all.

Fred Wright