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Re: ✘GPS 3.24 is released!
From: |
Gary E. Miller |
Subject: |
Re: ✘GPS 3.24 is released! |
Date: |
Sun, 8 May 2022 14:25:19 -0700 |
Yo Hal!
On Sun, 08 May 2022 13:55:32 -0700
Hal Murray <halmurray+gpsd@sonic.net> wrote:
> > Not priviledged, but syncrhouns only. gpsd needs to be async once
> > it is running. Otherwise the buffers back up and game over.
>
> Is the game really over? Will the pseudo threads parsing the input
> streams recover from lost data?
What psuedo threads?
> If so, what is the value of the DNS
> lookup (or whatever) that doesn't happen often compared to the
> occasional trashing of the input stream?
A whole bunch of timeouts trigger, devices and cleitns get disconnected,
etc. I tried and failed. Feel free to give it a try.
> > Of course if you want convert gpsd to multhreaded operation, then
> > those problems go away.
>
> I've done it for ntpd -- not real threads, just another quirk for the
> current pseudo thread scheduler to handle. It's not hard, at least
> if you are already familiar with threads.
The problem is I don't want to write my own dns client, and all the
FOSS ones are hard blocking.
> The general idea is to set a flag, fork a real thread to do the DNS
> lookup, than continue after the answer is available.
Have at it. Threads are not my thing. What DNS library can be threaded?
> The handshake code is a bit ugly/tricky since it is small pieces
> spread all over the place.
If it is only a bit ugly/tricky for you, then have at it.
> There are 2 areas to keep in mind. The DNS thread can't call utility
> routines unless they are thread safe. One obvious example is logging.
Which comes back to: what DNS library is hread safe?
> The other is that you can't have a lot of state on the stack when you
> want to do the DNS lookup. The DNS lookup gets tangled up with the
> top-level pseudo thread scheduler.
But that is exactly what people want. To do the DNS lookup long after
startup, when gpsd has grabbed a lot of state.
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
gem@rellim.com Tel:+1 541 382 8588
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- Re: ✘GPS 3.24 is released!, Ralph Nemitz, 2022/05/02
- Re: ✘GPS 3.24 is released!, Gary E. Miller, 2022/05/02
- Re: ✘GPS 3.24 is released!, Ralph Nemitz, 2022/05/03
- Re: ✘GPS 3.24 is released!, Ralph Nemitz, 2022/05/03
- Re: ✘GPS 3.24 is released!, Gary E. Miller, 2022/05/03
- Re: ✘GPS 3.24 is released!, Gary E. Miller, 2022/05/03
- RE: ✘GPS 3.24 is released!, Rick Howitt, 2022/05/08
- Re: ✘GPS 3.24 is released!, Greg Troxel, 2022/05/08
- Re: ✘GPS 3.24 is released!, Gary E. Miller, 2022/05/08
- Re: ✘GPS 3.24 is released!, Hal Murray, 2022/05/08
- Re: ✘GPS 3.24 is released!,
Gary E. Miller <=