1354723 - Understand what scripts in the browser front-end are run on timeouts and intervals

Status: RESOLVED FIXED

(Firefox :: General, enhancement, P1)

Description

[Mike Conley (:mconley) (:⚙️)]

I was discussing this with ehsan today. Having looked at a number of profiles, we're concerned that there are timers and intervals being queued that might run at any time on the main thread. It's kind of the wild west. We have no idea how many of these things there are, we don't know their performance characteristics, and we don't know how often they run.

We should probably get a sense of this, at least to put our minds a bit at ease.

Comment 1

[Will Wang [:WillWang]]

(In reply to Mike Conley (:mconley) from comment #0)
> that might run at any time on the main thread. It's kind of the wild west.

Bug 1365970 is about the blocking on _content process_, please remove this dependency if it's not for this meta bug.

Comment 2

[:Felipe Gomes (needinfo for replies!)]

Attachment: settimeouts.htm

This is all the de-duplicated setTimeout calls that I got during a browsing session where I tried to open all the main browser functionalities (bookmarks, add-ons manager, menus, etc)

Comment 3

[Mike Conley (:mconley) (:⚙️)]

If anybody ever picks this up, njn just pointed me at this document, which seems super relevant:

https://developer.mozilla.org/en-US/docs/Mozilla/Performance/TimerFirings_logging

Comment 4

[:Felipe Gomes (needinfo for replies!)]

Attachment: settimeoutlogging

All the work meant for photon startup perf was completed here. I meant to get back to this bug to investigate the non-startup timers, but that ship has sailed, and it's better handled in a new bug.  I'm attaching the hacky patch that I had here to log these setTimeout calls, and will close this bug.

Comment 5

[:Felipe Gomes (needinfo for replies!)]

(Note: the startup timers were fixed at bug 1388145)