1420563 - "Authentication Required" hangs Firefox when CPU is otherwise busy or throttled down

Status: RESOLVED WORKSFORME

(Firefox :: General, defect, P3)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Difficult to reproduce, but I've stumbled upon it many times:
1. Start Firefox
2. Start another task that uses 100% CPU (e.g., building firefox)
3. Open a website that requires HTTP basic authentication, e.g. https://jigsaw.w3.org/HTTP/Basic/ with username 'guest' and password 'guest'

Expected:
A. It should be possible to close the tab or go to another one.
B. It should be possible to interact with the drop-down, to enter the info and press Cancel/OK.

Actual:
A. Not possible, even when there is nothing else happening (e.g., task #2 doesn't run).
B. Firefox appears frozen (the Mac shows the spinning beach ball), including not being able to press OK/Cancel.
Stopping the #2 task usually helps, but sometimes not (In which case I had to forcefully close Firefox, i.e., crash it).
And it's not quite solidly "frozen", as I can see some animations still happening in the background; it's just non-responsive to any interaction.

I'm guessing that 'A' is a feature, to prevent any other interaction while the user is supposed to authenticate themself? (In which case, you may ignore this part of my complaint.)
But in addition to the annoyance of not being able to do anything else, the authentication dialog somehow blocks when CPU resources are limited, which then effectively hangs all of Firefox.

(And instead of running another heavy task, I've also experienced this when the laptop was in a hot environment and the CPU was throttled down.)

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

In case it's important:
Firefox Nightly 58, 3 windows with ~200 tabs open (but only a few visited/loaded).
MacBook Pro late 2013 with 4-core 8-thread 2.6GHz Intel i7, 16GB, Mac OS X 10.12.6.

Comment 2

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

(Sorry for the spam!)
I meant Nightly 59, of course.
But it was already happening in 58, 57 and I think before.

Comment 3

[Johann Hofmann [:johannh]]

Your first problem is a dupe of bug 613785. I'm not sure what the make of the other one. You're slowing down your computer on purpose. Does everything else stay snappy and just the auth dialog is choppy?

Comment 4

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

(In reply to Johann Hofmann [:johannh] from comment #3)
> Your first problem is a dupe of bug 613785.

Thank you for the info, Johann.
I'm dropping the interaction part from this bug, to focus on the freezing.

> I'm not sure what to make of
> the other one. You're slowing down your computer on purpose.

Slowing down is not my purpose! :-)
It just happens sometimes when I'm doing other heavy work, and/or when working in a hot environment which forces my laptop to throttle down the CPU to prevent it from catching fire.

> Does everything
> else stay snappy and just the auth dialog is choppy?

Everything else is still usable, but sluggish.
E.g., if there is no auth dialog, I can use Firefox just fine with 200+ tabs open, but of course it's a bit slow sometimes (slow to scroll, slow to respond to clicks on links, etc.).
But when the auth dialog is visible, I can't do anything: The OS thinks Firefox is non-responsive and displays the "spinning beach ball of death".
Frustratingly, I can see some web content and other UI elements still animate, so Firefox is not actually frozen, it just does not respond to any interaction.
All I can do at this point is either force-quit the app, or wait for things to cool down. And I'm pretty sure that I've had Firefox never recover, even when the laptop was back to normal (low CPU usage, no throttling). So there may be a real race that produces this never-ending deadlock state?

I don't expect Firefox to be "snappy", but I would expect it to still be moderately usable under these circumstances, i.e., I should be able to at least click on OK/Cancel to dismiss the auth dialog.

Comment 5

[landy2005]

I have same issue with HTTP auth.
Mac OS 10.10.5, Firefox 58.0.1.

Not sure about 100% cpu usage, for me this happened on any page with HTTP auth, also when CPU less 50% usage..

Comment 6

[Corey McKrill]

Mac OS 10.12.6, Firefox Developer 59.0b13 (but this has been happening for the last several versions)

When the basic auth overlay appears, the Mac OS spinning ball appears intermittently. When I try to type in my credentials, the lag between keystrokes and characters appearing is sometimes as much as 15 seconds. Occasionally I have had to force quite FF, as mentioned in the original report. I have not noticed it coinciding with other high-intensity CPU processes. Just whenever the basic auth overlay is open.

Comment 7

[Glenn Glazer]

I had exactly the same problem as Corey reports.  MacOS 10.13.3.  Firefox showed as Not Responding in Activity Monitor, 119% of CPU.  Upgrading FF from 58 to 59 solved it.

Comment 8

[sbyholm]

I have almost the same problem. Every time I do a HTTP auth Firefox freezes for over 10 seconds apparently while waiting for the auth to complete. I'm running Windows 7 and Firefox 59.0.2 and not much CPU usage.

Comment 9

[akhmedov]

I'm using Firefox for mac version 59.0.2 and this issue happens quite frequently, not sure about 100% CPU though. Sometimes it freezes for couple of seconds, other times for minutes. All Firefox windows are unusable during the freeze.

Comment 10

[Johann Hofmann [:johannh]]

With the new tab modal auth dialog I'm closing this as worksforme, feel free to re-open if this problem still exists in Nightly.