ubuntu-phone team mailing list archive

[Gerry Boland <gerry.boland@xxxxxxxxxxxxx>]

On Thu 27 Mar 2014 22:42:33 GMT, Michal Hruby wrote:
> On 27/03/14 22:18, Michał Sawicz wrote:
>> On 27.03.2014 22:49, Michal Hruby wrote:
>>> Just let Qt know that the shell window is obscured, that's when the
>>> render thread stops.
>> Problem here is that's racy - by the time the expose event reaches
>> whatever it needs to reach, the render thread might already be blocked
>> in eglSwapBuffers.
>
> I didn't back off from my suggestion to stop blocking and just return
> true there. It's not like turning off the display disallowed us from
> copying a buffer.
>



One worry I have about eglSwapBuffers blocking is what happens at 
unblock. It blocks when powering down the display. Unblock happens when 
the display is powered back up, however the GL pipeline still contains 
the commands for rendering the last frame before the screen was powered 
down. So at display on, the first frame rendered will be a 
before-display-off frame - which is bad.
Is there something I'm missing?
-G