[mythtv] wedged in watch recordings

[Daniel Kristjansson]

On Tue, 2008-01-22 at 19:18 -0500, George Nassas wrote:
> On 22-Jan-08, at 12:19 PM, R. G. Newbury wrote:
> It looks like a deadlock. I can't say if it will hang *forever* on the
> scale of geological time but it was stuck long enough for me to attach
> a debugger and also to wait while I stepped away for an hour to take a
> call. It looked like the thread was waiting for something to be
> released which had been locked higher up the stack. I'd say it's a
> deadlock.

It is quite possible that there is a deadlock. The live preview code
is quite messy. Stanley Kamithy is working on some preview/PiP playback
code in the mythtv-pip branch which will eventually replace this code,
but if you can find this deadlock so we can kill it before the 0.21
release, that would be great.

> A few months ago there was a post by Daniel K here or on the commits
> list about exactly this scenario. These sort of hangups were a lot
> more common back then so I suppose this is some corner case that has
> escaped detection. It would be good to track it down before the
> imminent release.

Yes, yes, and yes. The code is stable enough now that live preview
isn't something I immediately disable in on a new MythTV box. But
from looking at the code back then I would not be surprised if there
were still lurking problems.

> Anyway I was mostly looking for a pointer on how that part of the code
> works so I can hit the ground running the next time it sticks. It
> never seems to happen when I have a few spare hours on my hands.

Unfortunately, I don't remember much about it other than it was scary.
It was more than a 'few' months ago that I looked at this. I think it
was in fact before the 0.20 release, as we tried to stabilize MythTV
for that release.

-- Daniel