User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:80.0) Gecko/20100101 Firefox/80.0

Steps to reproduce:

Go to https://www.aliexpress.com
Do something like changing the language or go to My Account => My Orders
Firefox will hang immediately.

Note that I did remove my profile for this test for a clean start. It also happens with my regular profile. It does NOT happen with the same firefox version in Windows.

There is an Ubuntu bug report with additional technical details for this:
https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1895936

Actual results:

Firefox hangs. Note that other tabs will hang too, likely those who use the same process.

Expected results:

Webpage is usable.

Seems it does not happen with the official build from the webpage, so I'm closing this and just leave the Ubuntu bug open.

It just also happened with the official build. It's not as easy reproducible as with the ubuntu build but it happens after some time of heavy usage with multiple tabs.

=> Reopened.

Hey Sven,
I tried reproducing this on the latest versions of Firefox Nightly 82.0a1 (2020-09-20), beta 81.0 and release 80.0.1 on Ubuntu 18.04 and Ubuntu 20.04 but there was no hang for me.

Could you please send a record of this ?
If possible, you can test this issue on the nightly build as well. Download the build from : https://www.mozilla.org/en-US/firefox/nightly/all/ .
Can you test the issue while in Safe Mode? You can find helpful info here : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode .

Have you tried the Ubuntu-Build of Firefox? With that one it happend all the time. I could also reproduce it with a completely new profile with default settings and in safe-mode with that build.

The regular firefox build is more stable but still happens (only on Linux, not Windows). I need to use the browser heavily for some time and then go to aliexpress.

What kind of record do you need exactly?

I'm now using 82.0b4 and will see if it happens again.

Still the same. Happened after less than a day. If I open Aliexpress immediately after the launch, it works. When I tried it the next morning (after suspending the laptop over the night) it hung.

I experience this issue on different Mac computers, one running macOS 10.14.6 and another with 10.2.6.
On both Macs I have Firefox on the beta channel, right now it's version 82.0b6 but I started noticing this a few weeks ago.
I can tell you for sure that the problem occurs with pages that have some auto-start videos, animated gifs or something like that.
This page is even worse, it causes my old iMac (the one with macOS 10.12) to reboot in kernel panic after a few seconds it loads:
https://www.xmind.net/blog/en/xmind-2020-or-xmind-8-it's-not-a-problem/
On Chrome the same page is properly and smoothly displayed.

In Chrome everything is fine and strangely in Firefox on Windows also.
Aliexpress also uses a lot of animation and the other pages where the hang occurs also (unfortunately they are not public).
I think they are also using some mechanism to load addition content (XMLHttpRequest?)

Setting a component for this issue in order to get the dev team involved.
If you feel it's an incorrect one please feel free to change it to a more appropriate one.

Can you take a profile using https://profiler.firefox.com? That should give us a sense of where time is spent.

I tried that but then the tab that's supposed to display/submit the result also hangs.

Ok, can you try to take a profile using https://profiler.firefox.com/docs/#/./guide-perf-profiling?id=step-1-capture-the-profile and upload the test.perf script from step 2 somewhere?

Thanks, and sorry for the hassle :/

Here's the profile:
https://share.firefox.dev/37Gqb9z

I also tried it again with a new profile and today I could reproduce the issue three times in a row but every time the profiler tab hang. So here is the profile from the perf tool:
https://share.firefox.dev/3os500O

There are no symbols at all in that profile, so it's hard to know what might be going on. Which Firefox version are you using? Is there any chance to take a profile with an official build, such as the ones from https://nightly.mozilla.org?

In none of the two profiles? The first one was created with the firefox profiler...

I'm currently using the builds from the mozillateam:
deb http://ppa.launchpad.net/mozillateam/ppa/ubuntu focal main

The issues are still there. A few minutes ago I had a hang on mega.com but after a restart it was not reproducible.
Current version: 83.0 from mozillateam

Ah, the one from comment 13 does shed some light. It seems we're hanging under cubeb_backend::capi::capi_get_max_channel_count...

So it seems the audio IPC is just taking forever to respond... I'm not too familiar with that code though. Matt, does something like this ring a bell?