[mythtv] DVB SI rework - Help needed

[Roger James]

On 22 January 2017 2:58:23 pm Peter Bennett <pgbennett at comcast.net> wrote:

> On 01/22/2017 09:40 AM, roger wrote:
>> As a complete aside. If anyone reading this is interested in looking
>> at another fascinating bug in myth. Try running mythfrontend on a fast
>> 64bit linux frontend with a ssd drive, and starting the frontend from
>> an autostart file. Lots of interesting thread safety issues here! Just
>> remember that exit code 139 is probably a SIGSEGV and not a
>> GENERIC_EXIT_INVALID_TIME (Darn those overlaps between uncaught
>> signals and myth error codes when you are in a shell script ;-) ).
>
> I am working on the frontend startup, fixing the cases where the
> frontend starts before the database and similar issues. There is not
> normally a seg fault, just confusing prompts about entering your
> language and such. I don't know how to recreate your error. I don't have
> an ssd drive. Maybe if you have some more info I can look at it at the
> same time.
>
> Peter
>

Hi Peter

I did raise an issue on this a while back here

https://code.mythtv.org/trac/ticket/12909

And here

https://bugs.launchpad.net/mythbuntu/+bug/1635685

I coded up a fix for the crash in QImage but that just moved the crash a 
bit further down the mythfrontend initialisation sequence into a number of 
random other crashes all of which seem to be Qt signalling related. I can 
send you stack traces for these if you wish. I think I still have the cores.

This all seems to relate to Qt not being thread safe or reentrant in a lot 
of areas. This exacerbated by running on a fast multi core 64bit processor 
with a fast SSD drive.

Cheers

Roger