Bug 171986 – Mail spins launching spell checker when typing

• Component: New Bugs
• Status: RESOLVED FIXED

[Tim Horton]

Mail spins launching spell checker when typing

[Tim Horton]

Created attachment 309767 [details]
Patch

[Tim Horton]

Created attachment 309775 [details]
Patch

[Beth Dakin]

Comment on attachment 309775 [details]
Patch

r=me, but obviously take a look at those Mac bots.

[Tim Horton]

https://trac.webkit.org/changeset/216704/webkit

[Alexey Proskuryakov]

Comment on attachment 309775 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=309775&action=review

> Source/WebKit2/ChangeLog:15
> +        Asynchronously pre-warm the spell checker when a WKWebView becomes editable.

This is asynchronous, but still blocks the main thread just as much. What tracks a better fix?

[Tim Horton]

In my testing (and instruction from others), that is not true. It's still not perfect, but does not block the main thread for the launch time of the spell checking process. There's a test app attached to the radar if you want to experiment...

I do plan to experiment with actual async spell checking in the future but I don't think there's a bug about that yet.

[Alexey Proskuryakov]

If that's the case, why do it in dispatch_async, and not right away?

[Tim Horton]

(In reply to Alexey Proskuryakov from comment #7)
> If that's the case, why do it in dispatch_async, and not right away?

While *most* of the blocked time is now avoided, the first call to sharedSpellChecker in a process is still quite a bit more expensive than doing nothing (but on the order of tens of milliseconds instead of hundreds). I didn't want to regress time-to-first-paint.