1955028 - (Intermittent) Alt frecency recalculation is sometimes not triggered in the expected time window

Status: NEW

(Toolkit :: Places, defect)

Description

[Adrian Florinescu [:aflorinescu] [PTO until 04.23 ]]

Found in

• 138.0a1 (2025-03-18)

Affected versions

• 138.0a1

Tested platforms

• Affected platforms: Windows 10, Mac 11, Ubuntu 22.04

Preconditions

• set places.frecency.pages.alternative.featureGate to true
• set browser.places.interactions.viewer.enabled to true for debug purposes
• Restart Browser

Steps to reproduce

1. Navigate to any website and keep it in the foreground for 60 seconds.
2. Open query page and on the "Frecency" section inspect the 'recalc alt frecency' column for the opened site. (should be 1 at this point)
3. Close the open website to avoid backround recalculation, do not open any new tab, leve the query page open.
4. Idle the browser for 5' +
5. Verify the query page and on the "Frecency" section inspect the 'recalc alt frecency' column for the opened site.

Expected result

• recalc alt frecency is set to 0 and alt frecency is recalculated

Actual result

• In some cases, the recalc alt frecency is not set to 0, remains on 1, not being recalculated. Pretty intermittent, reproduced it more often on mac/ubuntu than on windows.

Additional Notes

• https://searchfox.org/mozilla-central/rev/be3db2aef8d3916c891527794a2d5e2f2dc9fab1/toolkit/components/places/PlacesFrecencyRecalculator.sys.mjs#80-83
  implies that if there is not idle found, the update task should run after 5' regardless.
• we caught cases in which the recalc alt frecency value would stay stuck @ 1 for 15-20' with an instance of 1h.
• seems like being active on the browser has an impact of not catching this behavior
• redo the same test for the same site multiple times to reproduce easier

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:mak, could you have a look please?

For more information, please visit BugBot documentation.

Comment 2

[James Teow [:jteow]]

I'll investigate this.

Comment 3

[James Teow [:jteow]]

I've been able to reproduce this, I need to determine the reason.