Bug 23317 – [Regression] Very high CPU usage with animation testcase

• Status: RESOLVED
• Resolution: FIXED
• Component: CSS

[David Smith]

Wave the mouse over the testcase (tested in r39882) and watch CPU usage, then compare doing the same in Safari 3.2.

[David Smith]

Created attachment 26707 [details]
Testcase

[David Smith]

Created attachment 26708 [details]
Shark trace

[Chris Marrin]

Created attachment 26853 [details]
Patch, including LayoutTest file

        The high CPU usage was really from repeatedly firing transitions caused
        by a bug in the way we handle background-color animations. If animating 
        from a valid background color to no background color, we sometimes left
        (based on timing) the background color as transparent black, but valid
        rather than invalid, which it should be. Fixing that got rid of the
        repeated firing.

        But we really were doing more expensive iteration of all objects with
        animations or transitions on them (running or not). So I added two
        optimizations to quickly short circuit when an object had no running
        animations or transitions. Things are now as zippy as ever.

[Dave Hyatt]

Comment on attachment 26853 [details]
Patch, including LayoutTest file

r=me

[Chris Marrin]

Sending        LayoutTests/ChangeLog
Adding         LayoutTests/transitions/repeated-firing-background-color-expected.txt
Adding         LayoutTests/transitions/repeated-firing-background-color.html
Sending        WebCore/ChangeLog
Sending        WebCore/page/animation/AnimationBase.cpp
Sending        WebCore/page/animation/AnimationController.cpp
Sending        WebCore/page/animation/CompositeAnimation.cpp
Sending        WebCore/page/animation/CompositeAnimation.h
Transmitting file data ........
Committed revision 40102.