Thank you for your replies! On Wed, Dec 6, 2017 at 8:48 AM, Olmstead, Don <don.olmst...@sony.com> wrote:
> We’re fine with removing it. > That's nice! > > > *From:* webkit-dev [mailto:webkit-dev-boun...@lists.webkit.org] *On > Behalf Of *Geoffrey Garen > *Sent:* Tuesday, December 5, 2017 2:35 PM > *To:* Michael Saboff <msab...@apple.com> > *Cc:* John N. Lehner <jleh...@apple.com>; WebKit-Dev < > webkit-dev@lists.webkit.org> > *Subject:* Re: [webkit-dev] Proposal: Do not support Windows fibers > > > > If our Windows clients are cool with it, I think we should remove support > for fibers. > > > > I don’t think our current implementation works super well with fibers. It > is best not to include half-working code in the tree. > > > > Geoff > Yeah, I think we should assume that WebKit is not supporting Windows fibers. > > > On Dec 5, 2017, at 11:19 AM, Michael Saboff <msab...@apple.com> wrote: > > > > Here is the reply from iTunes for the WebKit-Dev list > > > > - Michael > > > > —— > > > > From an iTunes perspective, WebKit can eliminate any remaining Windows > Fiber API support. > > > > iTunes still uses some cooperative threading, but implements its own > mechanism on top of regular preemptive Windows threads. And we believe > we've fixed all occurrences of calling WebKit/JSC from our non-main > cooperative threads. > > > > - John > > Nice. So Windows fiber is not used :) > > > On Dec 5, 2017, at 10:26 AM, Michael Saboff <msab...@apple.com> wrote: > > > > [Bringing John Lehner from the iTunes team into the discussion] > > > > Last I knew, the iTunes team uses fibers. IIRC, the thread they use to > call into WebKit/JSC only has one fiber, other parts of the app use > multiple fibers on one thread but don’t have JS objects active in those > threads / fibers. > > > > John, have things changed for iTunes on Windows such that we can eliminate > support for fibers? > > > > - Michael > > > > On Dec 5, 2017, at 10:16 AM, Ryosuke Niwa <rn...@webkit.org> wrote: > > > > Yeah, I don't think there is much need to support fibers. With features > like web workers, supporting fibers doesn't make much sense. > > Yeah. At least, I think the platform provided fibers are not encouraged in WebKit. > > - R. Niwa > > > > On Tue, Dec 5, 2017 at 9:44 AM, Yusuke SUZUKI <utatane....@gmail.com> > wrote: > > Hi, Webkittens, > > > > I would like to make sure OR declare that WebKit does not support Windows > fibers. > > While fiber related functions are used in WTF, I believe that it is > because fiber local storage (FLS) can have destructors. And it is not > intended to support fibers explicitly. > > > > Actually, I believe the current WebKit does not work well with Windows > fibers right now. > > For example, our JSC GC is conservative for stack and registers. It means > that GC needs to scan stack and registers to gather conservative roots. But > if your fiber is not executed at that time, JSC GC will miss to scan the > stack and registers of those inactive fibers. As a result, managed objects > will be collected if it is only referenced from the roots in the inactive > fibers. > > > > And I think we can potentially improve performance of our TLS by using > thread_local implementation in VC++ instead of using FLS. FLS is slow and > it causes some problems[1]. I'm not sure the performance characteristics > and implementation details of thread_local in VC++, but it's worth checking. > > > > So, I think we should not support Windows fibers. I would like to hear > opinions about it. > > > > [1]: https://bugs.webkit.org/show_bug.cgi?id=146448 > > > > Best regards, > > Yusuke Suzuki > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev > >
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