[linux-audio-dev] meterbridge 0.0.4

[Joern Nettingsmeier]

Steve Harris wrote:
> 
> On Mon, Sep 30, 2002 at 06:01:06 +0200, Joern Nettingsmeier wrote:
> > when i start an instance of meters jackd sometimes complains:
> >       cannot create new client; bridge already exists
> >       cannot complete new client connection process
> 
> That is just becuase it tried to connect as brdige, and if it cant tries
> bridge-<pid>

ok, i could have thought of that myself....

> > i also found it's advisable to re-start jack after a meter crash,
> > otherwise things get fishy (alsaplayer loses its jack connection during
> > meter startup and there are random crashes of jackd, alsaplayer and
> > meters).
> 
> Thats bad. In the stderr output, does it look like the meter manages to
> clean up after isself?

yes. it's just that meterbridge somehow causes alsaplayer to time out.
the jack crashes were not easy to pin down - i haven't come up with
anything reproducible yet.
 
> > the restoring of connections on exit succeeds almost always except when
> > it segfaults (which i can't seem to reproduce reliably). i closed some
> > of my 12 meters in random order, and the port connections were always
> > restored correctly. only sometimes it makes alsaplayer time out and
> > reconnect to jack, and all meters freeze - is that what one would expect
> > when the source is gone, or should they just drop to zero ?
> 
> No, they will freeze, making then return to zero would require more logic,
> so I didn't do it ;)

ok, i just wanted to make sure it's expected behaviour.
 
> > one minor problem: when you have multiple meters running and "killall"
> > them, things seem to happen in the wrong order, i.e. the port chain
> > breaks. but i don't see how meterbridge could avoid that, unless there
> > is a way to make the port restoration atomic.
> 
> Yeah, thats not fixable. Making them not crash is probably better.
> I'd like to get to the bottom of your segfual problem. I though id
> probably fixed it.

just to clarify, i mean killall -TERM, not killall -KILL. out of
curiousity, is there a way to tell the scheduler not to pre-empt the
process until the port cleanup is completed ? (sorry if this is a dumb
question, i don't know much about unix programming...)
not that i think this feature is really needed.

> > the input however i can't seem to get to work at all. it comes up,
> > displays a signal for maybe half a second, then bails out:
> 
> Thats bizarre.

agreed :)
 
i'll give it another beating tonight.
hope you are enjoying your trip to spain!

best,

jörn




-- 
Jörn Nettingsmeier     
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http://www.linuxdj.com/audio/lad/ (Linux Audio Developers)