1131382 - Compartment stats code uses wrong number of compartments

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: comp-stats

We added some code recently to return some information about compartments in the JS engine. Unfortunately, it relies on rt->numCompartments being the same as the number of compartments you get when you use CompartmentsIter. That turns out not to be true since CompartmentsIter skips over ExclusiveContext compartments.

Comment 1

[Luke Wagner [:luke]]

Comment on attachment 8561771 [details] [diff] [review]
comp-stats

Review of attachment 8561771 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jsapi.cpp
@@ +168,5 @@
>  
>  JS_PUBLIC_API(bool)
>  JS_GetCompartmentStats(JSRuntime *rt, CompartmentStatsVector &stats)
>  {
> +    if (!stats.reserve(rt->numCompartments))

Perhaps give a comment explaining the situation for future visitors; or just remove this reserve() since perf doesn't really matter here and you're checking growBy() for failure anyway.

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/aa48c1a176c5

Comment 3

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/aa48c1a176c5