950949 - Run extra forgetSkippable calls per CC not per slice

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Andrew McCreight [:mccr8] (PTO until 12-2)]

The extra forget skippable logic should be moved out of PrepareForCycleCollectionSlice and into BeginCycleCollectionCallback. This will require passing the extra forget skippable count via gCCStats.

This will fix the case where the browser is in the middle of an ICC, then nsJSContext::CycleCollectNow gets called with positive aExtraForgetSkippableCalls, which get triggered before the ICC is finished, and thus ignored.  This will also let us turn the dynamic check in nsCycleCollector::ForgetSkippable that we're idle into an assert.

I think this isn't pressing because we don't request extra forgetSkippable calls in normal circumstances, but it should be a nice cleanup.

Comment 1

[Andrew McCreight [:mccr8] (PTO until 12-2)]

Attachment: Run forgetSkippable per CC not per slice.

try run: https://tbpl.mozilla.org/?tree=Try&rev=b40db2b8506e

Comment 2

[Andrew McCreight [:mccr8] (PTO until 12-2)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ca04c2d514e1

Comment 3

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/ca04c2d514e1