OK, the runtime switch has landed in the WebKit tree as http://trac.webkit.org/changeset/52067 . We should pick it up next time we roll deps.
There should be no perf regression this time since we'll continue to use ATSUI on 10.5 and only switch to Core Text on 10.6.2 [like Safari]. This should also have the effect of fixing [or modifying the stack traces] we've been seeing for ATSUI crashes on 10.6. Best regards, Jeremy 2009/12/4 Jeremy Moskovich <jer...@chromium.org> > Thanks Drew, > > I'll look into toggling ATSUI/Core Text at runtime based on OS version > then. > > Best regards, > Jeremy > > > On Fri, Dec 4, 2009 at 5:25 AM, Drew Wilson <atwil...@chromium.org> wrote: > >> It looks like this had some negative perf issues: >> >> >> http://build.chromium.org/buildbot/waterfall/builders/Mac10.5%20Perf%281%29/builds/6289/steps/page_cycler_intl2/logs/stdio >> >> >> http://build.chromium.org/buildbot/perf/mac-release-10.5/intl2/report.html?history=150 >> (my DEPS roll was 33776) >> >> I'm going to revert. >> >> -atw >> >> 2009/12/3 Jeremy Moskovich <jer...@chromium.org> >> >>> Hi Drew & Albert, >>> >>> I picked your names off the WebKit sheriff calendar. >>> >>> I've landed a change to switch the Mac port over from ATSUI->Core Text >>> APIs on the WebKit tree at http://trac.webkit.org/changeset/51633 . >>> >>> If you see stability or performance issues on the next WebKit roll then >>> feel free to revert this CL (just drop me an email with a link to the bad >>> run if you do so, please). >>> >>> Thanks, >>> Jeremy >>> >>> 2009/11/24 Jeremy Moskovich <jer...@chromium.org> >>> >>> Thanks Hironori, >>>> >>>> I thought so too at the beginning but it turns out that they >>>> are available, just not declared in public headers. The WebKit bug I >>>> linked >>>> to has a patch that switches us to Core Text on 10.5 & 10.6. >>>> >>>> I'll do some perf tests and then we can make a decision based on that. >>>> >>>> Best regards, >>>> Jeremy >>>> >>>> 2009/11/24 Hironori Bono (坊野 博典) <hb...@chromium.org> >>>> >>>> Greetings Jeremy, >>>>> >>>>> This is just for your information. >>>>> It seems >>>>> "WebCore/platform/graphics/mac/ComplexTextControllerCoreText.cpp" >>>>> uses CTRunGetAdvancesPtr() and CTRunGetAdvances(), which are available >>>>> only on 10.6 or later. (This might be a reason why WebKit doesn't use >>>>> Core Text for Leopard?) >>>>> >>>>> (*1) < >>>>> http://developer.apple.com/mac/library/documentation/Carbon/Reference/CTRunRef/Reference/reference.html#//apple_ref/c/func/CTRunGetAdvancesPtr >>>>> > >>>>> >>>>> Best regards, >>>>> >>>>> Hironori Bono >>>>> E-mail: hb...@chromium.org >>>>> >>>>> On Tue, Nov 24, 2009 at 6:17 AM, Jeremy Moskovich <jer...@chromium.org> >>>>> wrote: >>>>> > Thanks Nico, >>>>> > I'll run some numbers. >>>>> > Best regards, >>>>> > Jeremy >>>>> > >>>>> > On Mon, Nov 23, 2009 at 11:15 PM, Nico Weber <tha...@chromium.org> >>>>> wrote: >>>>> >> >>>>> >> Did you do measuring if it's actually slower on 10.5? The CoreText >>>>> backend >>>>> >> for MacVim is much faster than the ATSUI backend from what I've >>>>> heard (then >>>>> >> again, MacVim doesn't do very complex text rendering). >>>>> >> >>>>> >> (Source: >>>>> http://groups.google.com/group/vim_mac/browse_thread/thread/b93c6dd5183bdc5e >>>>> ) >>>>> >> On Mon, Nov 23, 2009 at 12:58 PM, Jeremy Moskovich < >>>>> jer...@chromium.org> >>>>> >> wrote: >>>>> >>> >>>>> >>> Re http://crbug.com/27195 & >>>>> https://bugs.webkit.org/show_bug.cgi?id=31802 >>>>> >>> : >>>>> >>> >>>>> >>> Dan Bernstein says that Core Text on Leopard has performance issues >>>>> vs >>>>> >>> ATSUI so I'm going to look into switching APIs at runtime rather >>>>> than >>>>> >>> compile time. >>>>> >>> >>>>> >>> So we'd use ATSUI < 10.6 & Core Text >= 10.6 . >>>>> >>> >>>>> >>> Best regards, >>>>> >>> Jeremy >>>>> >>> >>>>> >>> >>>>> >>> -- >>>>> >>> Chromium Developers mailing list: chromium-dev@googlegroups.com >>>>> >>> View archives, change email options, or unsubscribe: >>>>> >>> http://groups.google.com/group/chromium-dev >>>>> > >>>>> > -- >>>>> > Chromium Developers mailing list: chromium-dev@googlegroups.com >>>>> > View archives, change email options, or unsubscribe: >>>>> > http://groups.google.com/group/chromium-dev >>>>> >>>> >>>> >>> -- >>> Chromium Developers mailing list: chromium-dev@googlegroups.com >>> View archives, change email options, or unsubscribe: >>> http://groups.google.com/group/chromium-dev >>> >> >> > -- Chromium Developers mailing list: chromium-dev@googlegroups.com View archives, change email options, or unsubscribe: http://groups.google.com/group/chromium-dev
