[LAU] question about jackdmp's ability to detect its soundcard has disconnected

[Ivica Ico Bukvic]

All,

I noticed since upgrading to Ubuntu 12.04 that the default Jack server is
jackdmp (v.1.9.8). Please correct me if I am wrong but my understanding this
is the smp-enabled version 2 that is being developed in parallel with 1.x
series of regular jack.

Either way, one of my concerns is that while in the old jack when one
accidentally pulled the soundcard jack was trying to talk to (e.g. a USB
soundcard), the jack would gracefully stop. The new version (and this could
be Ubuntu quirk) instead of stopping is pegged in some kind of a spinlock
that often times locks up the machine (this may be in part since I am
running a lowlatency kernel with audio group given priority) and at times
keeps it operational while hogging the cpu and making the computer barely
responsive until jackd is killed. Apps connected to jack that I tested so
far are also stuck in a loop waiting for a response from jack (although this
could be the app's shortcoming)--jack never broadcasts a signal that it has
lost the soundcard (AFAICT). FWIW I am running jackdmp through qjackctl...

Any thoughts on this matter would be most appreciated.

Ivica Ico Bukvic, D.M.A.
Composition, Music Technology
Director, DISIS Interactive Sound & Intermedia Studio
Director, L2Ork Linux Laptop Orchestra
Head, ICAT IMPACT Studio
Virginia Tech
Dept. of Music - 0240
Blacksburg, VA 24061
(540) 231-6139
(540) 231-5034 (fax)
ico at vt.edu
http://www.music.vt.edu/faculty/bukvic/