[mythtv] [mythtv-commits] Ticket #10506: threading/timing/logging-problem wath-recordings-screen

Michael T. Dean mtdean at thirdcontact.com
Sun Mar 25 00:09:57 UTC 2012

On 03/24/2012 07:15 PM, MythTV wrote:
> #10506: threading/timing/logging-problem wath-recordings-screen
> ---------------------------------+--------------------------------------
>   Reporter:  t.brackertz@…        |           Type:  Bug Report - General
>     Status:  new                  |       Priority:  minor
> Milestone:  unknown              |      Component:  MythTV - General
>    Version:  Unspecified          |       Severity:  medium
>   Keywords:                       |  Ticket locked:  0
> ---------------------------------+--------------------------------------
>   With 0.24 there had been no noticeable delays at all when playing in the
>   wath recordings screen. (Core i3, about 4000 recordings)
>   Since I updated to 0.25 there are delays everytime I change the recording
>   group (and when entering the watch recordings screen):
>   Changing the recording group takes about 1 second per 100 recordings in
>   the group I change into. During this time mythfrontend seems to be dead.
>   When entering the watch recordings screen the clock is runnning for a very
>   short time then it stops for about 40s before I see the all recordings
>   group.
>   There are no logging entries.
>   I suppose this is a threading/timing problem with the new logging: One
>   thread waits for another one until cathed by a timeout because of the
>   following observations:
>   1.
>   Sometimes (very rare) there is no delay at all
>   2.
>   Sometimes there is a much longer delay (minutes)
>   3.
>   Sometimes there is a delay after deleting a record.
>   4.
>   When entering wath-recordings-screen the harddisks work and the mouse
>   pointer reacts during the very short time the clock is running. Sometimes
>   there is some logging (which doesn't belong to the recordings screen but
>   something like housekeeping, start of a recording and so on.). In the
>   second (long) part of the waiting time the screen isn't updated any
>   longer. This means one can see the stopped clock and no mouse pointer.
>   When jumping to another window and then back to mythfrontend there is only
>   the background of the theme. I have never observed any logging during this
>   period, either, but many logging entries at the same time when the delay
>   is over.
>   During this time mythbackend (despite logging) works normal: Recordings
>   and jobs go on as usual.
>   The problem doesn't exist in mytharchive's choose-recordings-screen.

This sounds like:

(where the 3rd says to do the "Change Group Filter" to see if it's 
slow--and yours is).

Please try changing your DateFormat as specified in the 2nd post and see 
if it changes the timing.

>   Maybe the UI thread is waiting for the logging thread?
>   ---------------
>   There is a similar problem with mythtv-setup which may have a similar
>   reason:
>   - Choose a video source.
>   - Logging says:
>   {{{
>   Locking input devices
>   XMLTVConfig::Load: Running 'tv_find_grabbers baseline'.
>   }}}
>   - screen is not updated for 26 seconds and no logging entries during this
>   time
>   - screen shows properties of video source and the following logging-
>   entries appear:
>   {{{
>   Child PID 15543 killed with Beendet
>   XMLTVConfig::Load: Failed to run tv_find_grabbers
>   Unlocking input devices
>   }}}

That is because mythtv-setup runs the external command 
"tv_find_grabbers" and it takes so long to run on your system that 
mythtv-setup eventually gives up after its 25s timeout (i.e. your XMLTV 
install/configuration is broken).


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