Re: open SHM data only after cgps start

[Frank Nicholas]

Most people who have a long history with Unix do not like SystemD - it tries to 
do too many things and does most of them poorly.  It often gets in the way - 
THIS HAS BEEN ALL OF YOUR ISSUES.

I avoid systems with it, if I can.

Thanks,
Frank

> On Feb 5, 2021, at 1:56 PM, Hans Kurscheidt <lve0200@gmail.com> wrote:
> 
> Hi,
> 
> mails are crossing!
> 
> Last question, I don't know what you mean with systemD (UMB) (UMCest) etc.
> 
> RGDS
> 
> hk
> 
> 
> Am 05.02.2021 um 19:51 schrieb Gary E. Miller:
>> Yo Hans!
>> 
>> On Fri, 5 Feb 2021 18:52:19 +0100
>> Hans Kurscheidt <lve0200@gmail.com> wrote:
>> 
>>> I am now more than ever convinced that there's an issue in gpsd!
>> I think Fred has the answer, he knows much more about systemd(umb) tha I do.
>> 
>>> 1): fresh & clean boot; sudo lsof | grep /dev/ttyACM0 (my device
>>> (ublox 6 via USB)) => nothing open.
>> Not so fast.  As Fred said, systemd does not start gpsd until the
>> first network client connection.  SHM connections are ignored by
>> systemd(ubmer).
>> 
>> You can verity this way:
>> 
>> netstat -apn | fgrep :2947
>> 
>> 
>>> 2) starting my app; sudo lsof | grep /dev/ttyACM0 (my device (ublox
>>> 6)) => nothing open
>> Ditto above.
>>  
>>> starting cgps in parallel; sudo lsof | grep /dev/ttyACM0
>>> gpsd        700           nobody    9u      CHR      166,0 0t0
>>> 14619 /dev/ttyACM0
>>> 
>>> my app starts to receive data as well, like cgps.
>> Ditto above.  Fred explained this.
>> 
>>> after a while, my app does not receive anymore data (most likely when
>>> buffer has become empty); sudo lsof | grep /dev/ttyACM0 (my device
>>> (ublox 6)) => nothing open.
>> No.  Systemd(umbest) say no network connections and killed gpsd.
>> 
>> 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
>