[mythtv] mythfrontend on ubuntu 17.04 testing X11 ICE problems

[Stuart Auchterlonie]

On 05/02/17 10:33, roger at beardandsandals.co.uk wrote:
> 
> I appear to have lost outgoing SMTP mail. On the plus side. I think I may found the answer.
>             	
>             	----- Original Message -----
>             	From: roger roger at beardandsandals.co.uk
>             	To: Mythtv Developers mythtv-dev at mythtv.org
>             	Sent: Sat  4/02/17  8:02 PM
>             	Subject: Fwd: Re: mythfrontend on ubuntu 17.04 testing X11 ICE problems
> 
> 
> On 04/02/17 16:27, roger wrote:
>>
>>
>> On 04/02/17 15:30, roger wrote:
>>> I have set up my little Shuttle XS35V3 box as an ubuntu 17.04 
>>> testbed. I have built and and installed from the 2.8 fixes branch.
>>>
>>> I keep getting this from mythfrontend on stderr
>>>
>>> ICE default IO error handler doing an exit(), pid = 1752, errno = 32
>>> QWaitCondition: cv destroy failure: Device or resource busy
>>> QWaitCondition: mutex destroy failure: Device or resource busy
>>>
>>> The old trick of deleting the ..ICEauthority file seems to work if 
>>> you do it right after mythfrontend exits, this may be a red herring. 
>>> But unfortunately the error will reappear at some point, most likely 
>>> on the next boot.
>>>
>>> This problem seems to have been around for ages.
>>>
>>> Does anyone know what Qt is doing with ICE?
>>>
>>> Errno 32 is broken pipe. So what is dying and why?
>>>
>>> Seeing as I have hijacked the families myth box for testing, I am 
>>> keen to fix this :-).
>>>
>>> So all help will be gratefully received.
>>>
>>>
>>> Roger
>>>
>>
>> Sorry about the dual posting, the first one did not appear for until I 
>> posted the second.
>>
>> The top and bottom of this is that something appears to be killing the 
>> connection between mythfrontend and the X session manager. On the my 
>> setup the session manager is xfce4_sm. I have set XFSM_VERBOSE and 
>> have found something interesting.
>>
>> My backend  is configured for idle shutdown and wake on lan. The 
>> backend system runs the database server as well. If the backend system 
>> is not running then then mythfrontend goes into it wake on lan 
>> procedure. At some time in the distant past this started to prevent 
>> the gui from appearing, although I am not entirely sure about this, it 
>> might have always done it. This is what the session manager log shows 
>> happening.
>>
>> TRACE[xfsm-manager.c:1295] xfsm_manager_save_yourself_done(): 
>> enteringTRACE[sm-layer.c:162] sm_new_client(): ICE connection fd = 20, 
>> received NEW CLIENT
>>
>> TRACE[sm-layer.c:213] sm_register_client(): ICE connection fd = 20, 
>> received REGISTER CLIENT [Previous Id = None]
>>
>> TRACE[xfsm-manager.c:1607] xfsm_manager_save_timeout(): Client id = 
>> 2ac51c2aa-c28b-4b54-8412-69aec21ced14, received SAVE TIMEOUT
>>    Client will be disconnected now.
>>
>> This happens whilst the frontend is still waiting for the database 
>> connection to come up. When it does the frontend does a whole load of 
>> gui image loads the thing you see in the log in loading 
>> watermark/dvd.png at which point the ICE error occurs, presumably when 
>> the main loop tries to send something to the session manager.
>>
>> Roger
>>
> Ok I can see what is happening now MSqlDatabase::OpenDatabase in 
> mythdbcon.cpp has a sleep in the wake on lan loop. This is very 
> unfriendly in a gui environment as the main message loop does not get 
> actioned.
> 
> Possible fixes.
> 
> 1. Write a gui friendly version of OpenDatabase.

We definitely should do this.

> 
> 2. Move the wol stuff up into mythfrontend (I wonder if this was already 
> done in reverse in the past/).
> 
> 3. Do it in a wrapper.
> 
> 4. Do it in systemd.
> 

Not everyone uses systemd.

> 5. ?
> 

Profit $$$ of course ;-)


Regards
Stuart


> Roger
> 
> 
> 
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