1167323 - Use internal interfaces to implement MarkCycleCollectorChildren

Status: RESOLVED FIXED

(Core :: JavaScript: GC, defect)

Description

[Terrence Cole [:terrence]]

Attachment: specialize_markcyclecollectorchildren-v0.diff

This function used to live outside and was moved inside for performance. It never really got a full once-over to make full use of the fact that it's internal, however. This patch does:

* Change the interface to take CallbackTracer.
* Calls DoCallback directly where possible.
* Calls T::traceChildren instead of JS::TraceChildren.
* Moves everything from Marking.cpp to Tracer.cpp, since it's using CallbackTracer and DoCallback now.

Sorry about the awful diff; I realized after I finished that I should have done it in two patches.

Comment 1

[Jon Coppeard (:jonco)]

Comment on attachment 8608911 [details] [diff] [review]
specialize_markcyclecollectorchildren-v0.diff

Review of attachment 8608911 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/gc/Tracer.cpp
@@ +260,5 @@
> +
> +// This function is used by the cycle collector to trace through a shape. The
> +// cycle collector does not care about shapes or base shapes, so those are not
> +// marked. Instead, any shapes or base shapes that are encountered have their
> +// children marked. Stack space is bounded.

I don't think this is used to mark anything so we should say 'trace' rather than 'mark' here instead to avoid confusion.

Comment 2

[Andrew McCreight [:mccr8]]

The official cycle collector term is "traverse", FWIW. ;)  Trace is fine, too, of course.

Comment 3

[Terrence Cole [:terrence]]

Good catch, Jon! And thanks for the translation, Andrew! I've added a note to the comment.

Comment 4

[Terrence Cole [:terrence]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=1e8a50257699

Comment 5

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/dda6d9e077c8

Comment 6

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/dda6d9e077c8