I have recently been working on making it possible to achieve 60 fps animations in Elm (a compile-to-js functional language http://elm-lang.org/) programs backed by canvas.
I posted about progress and limitations on the Elm list https://groups.google.com/forum/#!topic/elm-discuss/ErEx6IZNNAQ and I thought some of the material might be interesting to the Mozilla JS implementers. Summarizing the relevant parts: 1. Elm produces kind of a lot of garbage. This seems to make it impossible to animate even simple scenes reliably at 60 fps in Firefox, but Chrome is doing a pretty good job. 2. You can compare the performance of my sample Elm program across browsers here: http://jsbin.com/cusahisozo 3. I also made a stripped down pure JS canvas animation and garbage collection benchmark. It has the advantage of having simple JS source code and tunable parameters that determine the rate of garbage allocation, but its disadvantage is that the garbage load is totally artificial, and might not be a good model for real programs. You can try it here (click "run with js" in the top right if it doesn't auto run): http://jsbin.com/puzojazapi/1/edit?js,output If you're interested, please see the description of the benchmark and a summary of my findings in the post on the Elm list linked above. I'll refrain from reproducing it all here. My overall conclusion is that Chrome seems to have significantly lower maximum GC pauses for this workload. 4. Thanks for adding Timeline to the dev tools. It's totally sweet! I can see that there is and has been a lot of hard work on improving the Firefox GC. I spent some time perusing open issues, and I read Nicholas Nethercote's post about Generational GC landing earlier this year https://blog.mozilla.org/nnethercote/2014/03/31/generational-gc-has-landed/. Anyway, my point is that I'm not trying to troll the Mozilla folks about the v8 GC being ahead along some axis--I just wanted to report a case study that might be a useful data point. Is there anything here that I should open a ticket about? _______________________________________________ dev-tech-js-engine-internals mailing list dev-tech-js-engine-internals@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals
