FYI, this did not land last week. However, I do intend to land it tomorrow pending a few last reviews.
Also, I ended up making changes that keeps our setTimeout() firing behavior closer to our old behavior. We can still fire slightly early as dictacted by our nsITimer implementation. Our precision should be approximately the same as behavior. The main benefit of this landing will be reduced allocation and locking overhead when setTimeout()/setInterval() is used. On Thu, May 25, 2017 at 11:00 AM, Ben Kelly <bke...@mozilla.com> wrote: > Hi all, > > I want to give everyone a heads-up that I'm hoping to push some > setTimeout() changes to inbound in the next day or two: > > https://bugzilla.mozilla.org/show_bug.cgi?id=1363829 > > The main result people should be aware of is that setTimeout() will be > more accurate and precise after this lands [1]: > > 1. We will no longer be able to fire setTimeout() handlers early. > 2. Assuming an idle main thread setTimeout() handlers will be less delayed. > 3. setTimeout(f, 0) may be a simple runnable dispatch now and can fire a > bit faster than before. > > As you can imagine, changing setTimeout() timings has interesting effects > on our test results. I've been working hard to find and fix intermittents, > but there will undoubtedly be some changes to our orange after landing this. > > If you have an intermittent you think appeared after this lands, please > look for any possible timing races in the test. Also, feel free to NI me > to help investigate. > > Again, I've worked hard to squash the intermittents I've seen in try, so I > don't believe there will be any super frequent failures from this bug. (Or > I wouldn't be landing, etc...) > > Please let me know if there are any questions or concerns. Thanks! > > Ben > > [1] For example, using this tool: > > https://people-mozilla.org/~bkelly/timeout-precision/? > mode=delta&delay=10&count=100 > > My current FF55 on windows 10 gives the following stats for "differences > from specified firing time" in milliseconds: > > min:-0.120 mean:1.922 median:1.830 max:5.180 stdev:1.753 > > So sometimes it fires as much as 120us early and has a median firing time > 1.8ms late. With bug 1363829 we get: > > min:0.010 mean:0.403 median:0.025 max:4.155 stdev:1.098 > > So we don't fire early any more and our median firing time is only 25us > late. > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
