kwin/backends/hwcomposer
Martin Gräßlin 93b5e13308 [hwcomposer] Rework the vsync code
This changes how we synchronize through vsync. We use a mutex and a
wait condition to synchronize the threads. When presenting the frame
our main gui thread blocks and will be woken up by the vsync event
(or a timeout of max 1 frame time slot). In order to minimize the
blocked time we use the blocksForRetrace functionality from the GLX
compositor.

Given this change we no longer need to tell the compositor that we
are swapping the frame, it's blocked anyway. Also we don't need the
failsafe QTimer anymore.

With this change applied on a Nexus 5 it's succeeding the "Martin
tortures phone test". It doesn't tear anymore and has a smooth
experience.

I'm rather disappointed by the fact that we need to block in order
to get vsync. This means Android/hwcomposer is as bad as GLX. So
much for the "Android stack is so awesome", in fact it's not. Anybody
thinking it's awesome should compare to DRM/KMS and especially atomic
modesetting. Yes it's possible to present frames without tearing and
without having to block the rendering thread.

Reviewed-By: Marco Martin and Bhushan Shah
2015-10-20 13:16:05 +02:00
..
CMakeLists.txt
egl_hwcomposer_backend.cpp [hwcomposer] Rework the vsync code 2015-10-20 13:16:05 +02:00
egl_hwcomposer_backend.h
hwcomposer.json
hwcomposer_backend.cpp [hwcomposer] Rework the vsync code 2015-10-20 13:16:05 +02:00
hwcomposer_backend.h [hwcomposer] Rework the vsync code 2015-10-20 13:16:05 +02:00
logging.cpp
logging.h
screens_hwcomposer.cpp
screens_hwcomposer.h