document.fonts.size needs to update style so it doesn't return stale values

• Component: New Bugs
• Status: RESOLVED FIXED

[Myles C. Maxfield]

document.fonts.size needs to update style so it doesn't return stale values

[Myles C. Maxfield]

Created attachment 436711 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 436711 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=436711&action=review

> Source/WebCore/css/FontFaceSet.cpp:115
> +    return m_backing->faceCountAfterUpdatingStyle();

Can a style update destroy |this|?

[Myles C. Maxfield]

Created attachment 436862 [details]
Patch

[Myles C. Maxfield]

Created attachment 436923 [details]
Patch

[Darin Adler]

Comment on attachment 436923 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=436923&action=review

> Source/WebCore/css/CSSFontFaceSet.cpp:108
> +    auto protect = makeRef(const_cast<CSSFontFaceSet&>(*this));

Self-protecting is not the correct pattern for our reference counting. Instead callers should be protecting the pointers of objects before they call functions. Please talk to Ryosuke about this if you don’t agree.

Also, we don’t need makeRef for this any more; if we wanted a "protector" we could write:

    Ref protect = const_cast<CSSFontFaceSet&>(*this);

But probably won’t be doing that.

> Source/WebCore/css/CSSFontFaceSet.cpp:110
> +        m_owningFontSelector->fontStyleUpdateNeeded();

Names here don’t make sense to me. This function’s name says "after updating style" which sounds asynchronous, but the name of the function we are calling says "update needed", which sounds like a request to schedule something in the future, asynchronously or lazily.

> Source/WebCore/css/CSSFontSelector.h:92
> +    void fontStyleUpdateNeeded();

Should rename this so it’s clear it’s a synchronous operation, not a passive notification that triggers something lazy in the future (as mentioned above).

> Source/WebCore/css/FontFaceSet.cpp:115
> +    return m_backing->faceCountAfterUpdatingStyle();

I find this function confusing. When would you call the "bad face count" function that doesn’t update style? Names really don’t make that clear.

> Source/WebCore/dom/Document.cpp:7447
> +    updateStyleIfNeeded(); // FIXME: This is unnecessary. Instead, the actual accessors in the FontFaceSet need to update style.

Seems like a good direction.

[Myles C. Maxfield]

Committed r281845 (241177@main): <https://commits.webkit.org/241177@main>

[Radar WebKit Bug Importer]

<rdar://problem/82618851>