Re: open SHM data only after cgps start

[Hans Kurscheidt]

Sorry Gary, you're giving me a hard time. As a long lasting UNIX expert you can't read plain vanilla C?? Are you trolling me??

May be you don't know VisualStudio, but C is C!

In the upper window you see this C code; this code is simple and not hard to read. The red point at the left line 202 is the breakpoint where the debugger has interrupted the execution (gdb on the target LINUX system). In the lower window you see the data of gps_data.fix. You, as a maintainer of gpsd should have no issues to recognize your own data structure. And PLEASE stop blaming systemd for everything. Until now, you've put nothing else on the table rather than stinky allegations against systemd, w/out anything proving a potential misbehavior of systemd related to the described problems!

The data sample was taken after:

• gpsd started at boot time by systemd, using "-n"
• the gpsd process was up & running
  
• the GPS device ublox 6 started cold after power up
• the APP started after multi-user level was reached from command line

During the time the GPS device was searching for a fix, the mode/status data was correct! The inconsistent data remained inconsistent over 30 min, after the GPS LED on the device itself flagged an available fix and gpsd was incorrectly showing mode=3 and status =1, but Lat/Log=0.

As I said b4, as an end-user I am not supposed to dive into the gpsd code to its full extend. I therefore don't know, how you mutex the writing to the SHM. In any case, my APP wouldn't mind to get a mixture of t0 and t-1 data, as long as the data is reasonable. Mode=3 and status=1, but Lat/Log data =0 while Satellites-used is happily updated every second, is not acceptable, unless for the very 1st read.

Yours

hk

Am 06.02.2021 um 21:34 schrieb Gary E. Miller:

> Yo Hans!
>
> On Sat, 6 Feb 2021 20:26:17 +0100
> Hans Kurscheidt <lve0200@gmail.com> wrote:
>
> > I really getting ready to run away.
> >       
> Why?
>
> > Please take a look the this 
> > screenshot from VisualStudio!
> >       
> Sorry, reading screen shots of code, on an editor I hae never seen, in
> a language I don't read, does not work for me.
>
> > gpsd 3.22 now running w/ "-n"
> >       
> And still under systemd(ubmer)?
>
> Before, or after running cgps?
>
> > Mode 3 = 3D, Status "Fix available" and then look at the data
> > provided...
> >       
> What is "data provided".  I just see a screen shot I don't understand.
>
> Is there something you don't understand?
>
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
> 	gem@rellim.com  Tel:+1 541 382 8588
>
> 	    Veritas liberabit vos. -- Quid est veritas?
>     "If you can't measure it, you can't improve it." - Lord Kelvin
>