[mythtv] Ticket #9223: Sluggish menu when watching a recording

[John Sturgeon]

On Feb 10, 2011, at 9:06 PM, Mark Kendall wrote:

> On 11 February 2011 12:46, John Sturgeon <john.sturgeon at gmail.com> wrote:
>> On Feb 10, 2011, at 8:24 PM, MythTV wrote:
>> 
>> #9223: Sluggish menu when watching a recording
>> -------------------------------------+--------------------------------
>> Reporter:  glemsom@…                |          Owner:  markk
>>     Type:  defect                   |         Status:  infoneeded_new
>> Priority:  minor                    |      Milestone:  0.24.1
>> Component:  MythTV - Video Playback  |        Version:  0.24-fixes
>> Severity:  medium                   |     Resolution:
>> Keywords:  sluggish menu            |  Ticket locked:  0
>> -------------------------------------+--------------------------------
>> 
>> Comment (by markk):
>> 
>> Thanks to John and Brian, I now have a couple of fixes/0.24 binaries that
>> display the issue.
>> 
>> Having re-read dgatwood's analysis and comments above, looked at the
>> commit that introduced the issue (or moved it from painfully sluggish to
>> totally unresponsive a328d996b94f62814cf065e60311d973283ec6c8) and
>> considered the Qt version differences, I think the UI thread blocking
>> issues are not the issue here.
>> 
>> What is probably relevant is how Qt is handling the event loop internally,
>> which I imagine may well be different between cocoa and carbon builds.
>> With the cocoa build, the event loop is clearly being processed as
>> expected and for carbon - not. Hence no CFRunLoop references as dgatwood
>> noted.
>> 
>> So, in the commit I've referenced above, the only piece that would appear
>> to change the behaviour of the main event loop is the addition of
>> hasPendingEvents() check. The Qt source for QEventDispatcher_mac is chock
>> full of #ifdef QT_MAC_USE_COCOA, so trying to unpick the Qt internals
>> isn't going to be fruitful.
>> 
>> But by way of a quick and easy test, can someone try removing the
>> hasPendingEvents() check in tv_play (there's only one use) and see if that
>> helps. It may well simply revert to the previous sluggish behaviour but at
>> least that will be progress of sorts.
>> 
>> There is only one instance of hasPendingEvents and that's in
>> mythmainwindow.cpp:
>> void MythMainWindow::SetDrawEnabled(bool enable)
>> {
>> [snip]
>>         while (QCoreApplication::hasPendingEvents())
>>             d->m_setDrawEnabledWait.wait(&d->m_setDrawEnabledLock);
>>         return;
>>     }
>> [snip]
>> }
>> Did you want me to comment the entire loop?
> 
> John
> 
> Line 368 of libs/libmythtv/tv_play.cpp (in fixes/0.24 anyway)
> 
> regards
> 
> Mark

That did it!

Thanks Mark, pausing, skipping is better than I've ever seen it on 0.24.  WAF ++++

-- 
John <><