Bug 102985 – Rename the "eden" bit to something more descriptive

• Component: New Bugs
• Status: RESOLVED FIXED

[WebKit Review Bot]

Rename the "eden" bit to something more descriptive
Requested by abarth on #webkit.

[Adam Barth]

3:14 PM <anttik> abarth: ping
3:14 PM <abarth> anttik: hi
3:14 PM <rniwa> anttik: and here comes the patch: https://bugs.webkit.org/show_bug.cgi?id=102983 :D
3:14 PM <anttik> abarth: what is InEdenFlag in Node.h?
3:15 PM <abarth> anttik: it's a bit that records whether this node has participated in a minor GC cycle
3:16 PM <anttik> abarth: is that some v8 specific name? it makes no sense at all
3:16 PM <abarth> anttik: its from https://bugs.webkit.org/show_bug.cgi?id=98725
3:16 PM <abarth> anttik: it's just a name we made up.  we can change the name if you like
3:16 PM <abarth> it refers to the garden of eden
3:16 PM <anttik> abarth: the webkit style prefers descriptive names
3:17 PM <anttik> so yeah, it should be renamed
3:26 PM <othermaciej> anttik, abarth: if you flip the polarity it could be HasSurvivedV8Collection
3:26 PM <othermaciej> or something
3:26 PM <othermaciej> I also thought "eden" was a bit of a wonky name, sorry for not commenting earlier
3:26 PM <abarth> yeah, i think eric mentioned not liking the name either
3:27 PM <abarth> MightBeReachableFromOutsideTheV8NewSpace
3:28 PM <anttik> Flag
3:28 PM <abarth> flag?
3:29 PM <anttik> MightBeReachableFromOutsideTheV8NewSpaceFlag :D
3:29 PM <abarth> .com
3:31 PM <othermaciej> abarth: what does "in eden" actually mean?
3:31 PM <othermaciej> from the patch it seemed like, mechanically, it would be unset if you survive a minor collection, but I may have misunderstood
3:33 PM <abarth> what it really means is "its too hard to calculate the reachability of this node during minor gc---you'll need to wait for a major gc"

[Kentaro Hara]

MaybeInV8NewSpaceFlag ?

[Adam Barth]

We might need to flip the bit in the future if the node is reachable from something like a MuationObserver that has a complicated lifetime.  Hopefully we can find a name that will scale to that case as well.

[Kentaro Hara]

In IRC, it looks like we have reached "CollectableOnlyDuringV8MajorGC". If you have no objection, I'll rename it.

[Kentaro Hara]

The conclusion in IRC was V8CollectableOnlyDuringMajorGCFlag. However, I noticed that then we need to set the bit in a Node constructor. To avoid the overhead (though I don't know it's a problem), I would suggest V8CollectableDuringMinorGCFlag. It's shorter than V8CollectableOnlyDuringMajorGCFlag:)

[Kentaro Hara]

Created attachment 175570 [details]
Patch

[Adam Barth]

Comment on attachment 175570 [details]
Patch

ok

[WebKit Review Bot]

Comment on attachment 175570 [details]
Patch

Clearing flags on attachment: 175570

Committed r135498: <http://trac.webkit.org/changeset/135498>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.