1629951 - Personality Provider worker should terminate

Status: VERIFIED FIXED

(Firefox :: New Tab Page, defect, P1)

Description

[Scott [:thecount] Downe]

We don't need to terminate the worker generally.

But if there is a case where a pref changes, we might still instantiate a new one, and teardown any existing ones. In this case, we should probably terminate the worker freeing up the memory in the worker thread.

Comment 1

[Scott [:thecount] Downe]

[Tracking Requested - why for this release]:

Comment 2

[Ryan VanderMeulen [:RyanVM]]

It's not clear to me that there's any major user-facing impact from this bug, so no need to track it for 76/77 AFAICT. That said, I'm still fine accepting a low-risk patch for uplift once one is ready and nominated for approval.

Comment 3

[Scott [:thecount] Downe]

Attachment: Bug 1629951 - Ensure we terminate worker if prefs are changed causing worker to be impacted.

Comment 4

[Scott [:thecount] Downe]

To test:

1. Have the multi process debugger open.
2. Create a brand new profile
3. Set browser.newtabpage.activity-stream.asrouter.devtoolsEnabled to true
4. Open about:newtab#devtools-ds
5. Ensure "show_spocs" is checked
6. Scroll down a bit and click "Enable V2 Personalization"
7. Scroll up and click "Trigger Idle Daily"
8. You should now have all the attachments from remote settings downloaded.
9. Scroll up and click "Expire Cache"
10. Scroll up and click "Trigger System Tick"
11. Check the multi process debugger for sources, and look for PersonalityProviderWorker.js.
12. Click refesh cache
13. Click trigger idle-daily
14. Repeat steps 12-13

Expected: Should only see 1 instance of PersonalityProviderWorker.js in multi process debugger.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cea2a87071fc
Ensure we terminate worker if prefs are changed causing worker to be impacted. r=gvn

Comment 6

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/cea2a87071fc

Comment 7

[Marius Coman [:mcoman], Ecosystem QA]

I have verified that this issue is no longer reproducible with the Latest Firefox Beta (77.0b2 Build ID - 20200505174119) and the latest Firefox Nightly (78.0a1 Build ID - 20200507085231) installed, on Ubuntu 18.04 x64 and Mac 10.15.3. I can confirm that only one instance of "PersonalityProviderWorker.js" is displayed in the multi-process debugger.