Bug 88541 – [V8] Keep TextTrackList alive as long as its owner is alive

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Erik Arvidsson]

[V8] Keep TextTrackList alive as long as its owner is alive

[Erik Arvidsson]

Created attachment 146306 [details]
Patch

[Erik Arvidsson]

This is a stop gap solution for TextTrackList. The end solution is to do use V8GCController but I haven't gotten that to work reliably.

[Adam Barth]

Comment on attachment 146306 [details]
Patch

Ok.  Can you add a FIXME to explain the right way of doing this?

[anton muhin]

Comment on attachment 146306 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=146306&action=review

> Source/WebCore/bindings/v8/custom/V8TextTrackListCustom.cpp:48
> +    Node* element = impl->owner();

May TextTrackList change owners?

[Erik Arvidsson]

(In reply to comment #4)
> (From update of attachment 146306 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=146306&action=review
> 
> > Source/WebCore/bindings/v8/custom/V8TextTrackListCustom.cpp:48
> > +    Node* element = impl->owner();
> 
> May TextTrackList change owners?

No. TextTrack objects may change owners but the TextTrackList itself doesn't change owner.

[anton muhin]

Comment on attachment 146306 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=146306&action=review

>>> Source/WebCore/bindings/v8/custom/V8TextTrackListCustom.cpp:48
>>> +    Node* element = impl->owner();
>> 
>> May TextTrackList change owners?
> 
> No. TextTrack objects may change owners but the TextTrackList itself doesn't change owner.

I see, great.  May one reach owner of TextTrackList from the item via JS DOM API?

[Erik Arvidsson]

(In reply to comment #6)
> (From update of attachment 146306 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=146306&action=review
> 
> >>> Source/WebCore/bindings/v8/custom/V8TextTrackListCustom.cpp:48
> >>> +    Node* element = impl->owner();
> >> 
> >> May TextTrackList change owners?
> > 
> > No. TextTrack objects may change owners but the TextTrackList itself doesn't change owner.
> 
> I see, great.  May one reach owner of TextTrackList from the item via JS DOM API?

No, there is no way to get to the owner from the TextTrackList in JS. (See TextTrackList.idl etc for details)

[anton muhin]

(In reply to comment #7)
> (In reply to comment #6)
> > (From update of attachment 146306 [details] [details])
> > View in context: https://bugs.webkit.org/attachment.cgi?id=146306&action=review
> > 
> > >>> Source/WebCore/bindings/v8/custom/V8TextTrackListCustom.cpp:48
> > >>> +    Node* element = impl->owner();
> > >> 
> > >> May TextTrackList change owners?
> > > 
> > > No. TextTrack objects may change owners but the TextTrackList itself doesn't change owner.
> > 
> > I see, great.  May one reach owner of TextTrackList from the item via JS DOM API?
> 
> No, there is no way to get to the owner from the TextTrackList in JS. (See TextTrackList.idl etc for details)

Great, then LGTM too.

[Erik Arvidsson]

(In reply to comment #3)
> (From update of attachment 146306 [details])
> Ok.  Can you add a FIXME to explain the right way of doing this?

Sorry, I thought I replied to this already.

We have this pattern in a few places already and we have open bugs to let V8GCController handle these using implicit references.

[Adam Barth]

> We have this pattern in a few places already and we have open bugs to let V8GCController handle these using implicit references.

Ok.  :)

[WebKit Review Bot]

Comment on attachment 146306 [details]
Patch

Clearing flags on attachment: 146306

Committed r119853: <http://trac.webkit.org/changeset/119853>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.