31 Jan
2018
31 Jan
'18
8:30 a.m.
How does the rc.local start jackd under the user
account? Maybe it could
start a screen session at that point, and when you ssh in you can connect
to the screen session. If you are not familiar with screen it is an
application that (among other features) will let you disconnect an ssh
session while the underlying terminal session continues to run (usually
breaking the ssh session will kill the terminal session associated with
that login). When you connect again with ssh you start screen with the -r
argument to restore connection to the already running screen session
rather than starting a new session.
As shown here (I wrote that msg in the forum):
http://forum.audioinjector.net/viewtopic.php?f=5&t=2727&e=1&vie…
sudo runuser -u pi -- /home/pi/start_jack
And right now everything works, strace gives me:
...
connect(3, {sa_family=AF_UNIX, sun_path="/dev/shm/jack_default_1000_0"}, 110) =
0
...
And jack_lsp works as expected. Contents in /dev/shm:
pi@realtimepi:~ $ ls -al /dev/shm/
total 69804
drwxrwxrwt 2 root root 160 Jan 31 15:24 .
drwxr-xr-x 14 root root 3300 Jan 31 15:19 ..
-rw-r--r-- 1 pi pi 71390368 Jan 31 15:22 jack-1000-0
-rw-r--r-- 1 pi pi 1240 Jan 31 15:22 jack-1000-1
srwxr-xr-x 1 pi pi 0 Jan 31 15:22 jack_default_1000_0
-rwxr-xr-x 1 pi pi 12 Jan 31 15:22 jack_sem.1000_default_freewheel
-rwxr-xr-x 1 pi pi 12 Jan 31 15:22 jack_sem.1000_default_system
-rw-rw-rw- 1 pi pi 70744 Jan 31 15:22 jack-shm-registry
When it is not working, the "jack_default_1000_0" file does not exist anymore,
but the jackd server is running.
I'll lookup the screen option, although this feels like more fundametal problem. The
files in /dev/shm aren't supposed to vanish during lifetime of jackd process, right ?
Regards
/Robert