[Jack-Devel] jackdus - was Re: Jack 1.9.7 on ARM crashes when killing a client
On 02/19/2011 07:13 PM, torbenh wrote:
> On Sat, Feb 19, 2011 at 02:22:26PM +0100, Robin Gareus wrote:
>> On 02/18/2011 12:23 PM, torbenh wrote:
>>> On Thu, Feb 17, 2011 at 02:01:06PM +0100, Robin Gareus wrote:
>> [..]
>>>>
>>>>
>>>> while you're at it: Would it be unreasonable to ask looking into
>>>> ignoring device disconnect? f.i. have jackd survive and not crash
>>>> when an interface (eg ALSA-USB) goes away.
>>>>
>>>> No further action should be taken by JACK (well, maybe some
>>>> hook-script could be invoked or a d-bus command send); some 3rd
>>>> party software could issue d-bus commands to switch backends.
>>>
>>> i basically did this with tschack. using pyjackd this should be
>>> working. not well tested, as i dont have an usb soundcard with me
>>> very often.
>>
>> I've updated jackdmp and tschack to latest svn/git and check this with a
>> USB UA-25. annotated logs attached.
>>
>>
>> tschack (git 7b7a48d)
>> terminates with exit 0 if the interface goes away.
>
> you did not use pyjackd.
> the jackd binary that comes with tschack is supposed to behave excactly
> like a jackd binary should.
> i didnt add a callback to the control api yet. but pyjackd should be
> ignoring the SIGUSR2 thats sent to the process leader upon backend exit.
>
> so it probably wont exit.
> the behaviour of tschack while it doesnt have a backend, is probably not
> really nice. (there are places where it waits for a graph switch)
> this is definitely fixable though.
Hi Torben,
mmh. python/jackd.py is not executable. I could neither find a dbus
.service file nor a README and and
http://hochstrom.endofinternet.org/trac/tschack does not tell much about
it either.
How do I launch tschack's dbus control server? Can I do so in a sandbox
or chroot (1)?
with jack2, I can use a few symlinks with LD_LIBRARY_PATH and
JACK_DRIVER_DIR to start 'jackdbus auto' and run the whole thing from
the source-tree. This schema only works with tschack's jackd, but not
with jackd.py.
(1) Well.. I don't wanna mess up my main systems and a VM is not good
for testing physical-sound I/O.
>> jack2d 1.9.7~svn4120 ( --classic --dbus )
>> keeps running when the USB/ALSA interface goes away - it no longer
>> live-locks or crashes. - All JACK clients stall.
>> With the dbus-version: the backend can be changed. After switching to a
>> new backend (here: internal card) JACK resumes to run nicely.
>>
>> After the device had been disconnected, the current port-connections can
>> no longer be queried (jack_lsp can not connect) until the backend is
>> re-initialized with `jack_control sm`.
>> Calling 'switch-master' re-creates the physical output ports and the
>> information about previous port-connections to the outputs are lost.
I found a way around this. jackdbus' org.jackaudio.JackPatchbay
interface keeps an independent internal connection list. It is also much
faster to use this (compared to jack_lsp and jack_connect).
Alas it is/was buggy: http://trac.jackaudio.org/ticket/213
> loss of port-connections is to be expected. its a backend switch.
> the ports might be different. recreating the correct connections, should
> be done by some kind of sessionmanager. this is out of scope for jackd.
>
indeed. jackd should just signal the condition. Some other tool should
take care of handling the condition (switch backends or not,
re-connect ports or map them depending on the interfaces switched
between...)
If you want to see a prototype in action: http://rg42.org/blog/jack2dbus
The good-news: it works. the bad-news: it's not sth. my mum could
install on her desktop [,yet]. Somehow it also feels from to be
"pioneering" JACK desktop-integration in 2011.
ciao,
robin
--
Robin Gareus
web: http://gareus.org/ mail: [hidden]
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