[OT] The ART runtime presentation at Google I/O 2014

[w0rp via Digitalmars-d]

On Saturday, 28 June 2014 at 06:23:25 UTC, Paulo Pinto wrote:
> Hi,
>
> posting this talk here, as Java performance on Android is often 
> mentioned in the discussions about GC vs RC performance.
>
> So here you have the Android  team explaining:
>
> - Dalvik GC sucks and is a basic stop the world implementation 
> with pauses > 10ms
>
> - ART solves the GC issue by adopting multiple concurrent GC 
> algorithms,
> depending on the application state thus reducing the stop down 
> to 3ms. More optimizations still to be done until the final 
> release
>
> - JIT compiler optimized for battery life and low power 
> processors, thus only very hot methods get actually compiled to 
> native code
>
> - Performance sorted out, by doing AOT compilation on install, 
> similar to approach taken by OS/400, Windows Phone 8
>
> https://www.youtube.com/watch?v=EBlTzQsUoOw
>
>
>
> --
> Paulo

I like his focus on the duration of frames per second. If you are 
aiming for 60FPS, you are aiming for a time period of about 16ms 
to 17ms per frame. So he mentions the current Dalvik GC occupying 
about 10ms for a collection in most cases, leading to a single 
dropped frame, and a near full memory case leading to about 50ms 
and above, leading to a few dropped frames. So when thinking 
about optimising GC, aiming for a collection time small enough to 
fit comfortably inside a frame seems like a good way to think 
about it.