Introduce the render thread of HWUI on android

1. RenderThread of
HWUI on Android
Rouyun Pan

2. RenderThread Draw first frame

3. Java - Choreographer
• Choreographer: drawFrame() ->
ViewRootImpl: performTraversals () ->
performDraw() ->
draw(boolean fullRedrawNeeded)

4. HW Renderer
*Path:frameworks/base/core/java/android/view/ViewRootImpl.java

5. ThreadedRenderer
*Path:frameworks/base/core/java/android/view/ThreadedRenderer.java

6. Native:nSyncAndDrawFrame()
*Path: frameworks/base/core/jni/android_view_ThreadedRenderer.cpp
*Path: frameworks/base/libs/hwui/renderthread/RenderProxy.cpp

7. Native: DrawFrameTask
*Path: frameworks/base/libs/hwui/renderthread/DrawFrameTask.cpp

8. Queue a RenderTask
*Path: frameworks/base/libs/hwui/renderthread/RenderThread.cpp

9. HWUI-RenderThread

10. DrawFrame

11. syncFrameState(1)
• Sync frame state from MainThread to RenderThread
for parallel.

12. syncFrameState(2)

13. makeCurrent

14. prepareTree(1)

15. prepareTree(2)

16. Draw(1)

17. Draw(2)
*Path: frameworks/base/libs/hwui/renderthread/CanvasContext.cpp

18. Compare between android 4&5
*UI Mainthread on Andoid 4.0
*UI MainThread and RenderThread on Andoid 5.0
RenderThread can wake the MainThread up in advance

19. Q & A