Opened 20 years ago

Closed 20 years ago

Last modified 20 years ago

#1078 closed defect (fixed)

Frontend segfault (PreviewGenerator related?)

Reported by: torbjorn.jansson@… Owned by: danielk
Priority: minor Milestone: 0.19
Component: mythtv Version: head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

i updated to the latest svn rev today and i got the frontend to segfault.

i was watching a recording when it stopped and i was back at the watch recording screen, so i tried to start playback again of it so i could check the ending of it and that's when the frontend segfaulted. the backtrace is from a coredump so it contains only one thread, i hope it's good enough.

output from "mythfrontend --version" 

Library API version: 0.19.20060115-1
Source code version: 8671
Options compiled in:
 linux debug using_xvmcw using_v4l using_oss using_alsa using_arts using_ivtv using_dbox2 using_lirc using_joystick_menu using_dvb using_dvb_eit using_x11 using_xv using_xrandr using_xvmc using_xvmc_vld using_frontend using_backend

Attachments (3)

frontend segfault.txt​ (15.6 KB ) - added by torbjorn.jansson@… 20 years ago.
backtrace from coredump
bt2.txt.bz2​ (3.7 KB ) - added by torbjorn.jansson@… 20 years ago.
bt from coredump with patch from daniel
log2.txt.bz2​ (7.2 KB ) - added by torbjorn.jansson@… 20 years ago.
frontend log file with -v playback for bt2.txt.bz2

Download all attachments as: .zip

Change History (6)

by torbjorn.jansson@…, 20 years ago

Attachment: frontend segfault.txt​ added

backtrace from coredump

comment:1 by danielk, 20 years ago

Milestone: → 0.19
Owner: changed from Isaac Richards to danielk
Version: → head

comment:2 by danielk, 20 years ago

Resolution: → fixed
Status: new → closed

(In [8717]) Fixes #1078. References #956.

The fix for #956 made the invalid assumption that shutting down the ~PlaybackBox() should never take longer than 500 ms to finish. This was a zombie prevention measure. I've removed the timeout, and I've also implemented a deleteLater() function which cleans up some things early, and should give us snappier preview response.

Torbjorn, can you run with '-v playback' for a while, and then grep for "previewThreadDone took" in the logs, I'd like some info on how long this takes in the longest case on your system. On my system it never takes longer than 7 ms, which is why I thought a 500 ms timeout would be safe. Maybe I can use a 5 minute timeout or something like that..

by torbjorn.jansson@…, 20 years ago

Attachment: bt2.txt.bz2​ added

bt from coredump with patch from daniel

by torbjorn.jansson@…, 20 years ago

Attachment: log2.txt.bz2​ added

frontend log file with -v playback for bt2.txt.bz2

comment:3 by torbjorn.jansson@…, 20 years ago

backtrace and matching logfile from frontend attached with patch from daniel.

the frontend version is: 

# mythfrontend --version
Library API version: 0.19.20060121-2
Source code version: 8733M
Options compiled in:
 linux debug using_xvmcw using_v4l using_oss using_alsa using_arts using_ivtv using_dbox2 using_lirc using_joystick_menu using_dvb using_dvb_eit using_x11 using_xv using_xrandr using_xvmc using_xvmc_vld using_frontend using_backend
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