GC slows down Threema Web on Firefox

[Elsensee]

Bug Description

I noticed while typing that once in a while (every few seconds) Threema Web would slow down (as in.. stop doing anything) and later "catch up" (in the case of typing, the characters previously typed would appear).

I wondered what was going on, stepped into the profiler and noticed a huge gap. investigating this further I found out, that there was a GC running. (I started typing around the 4.8 seconds mark)

Steps to Reproduce (for bugs)

This is now complicated, because the problem doesn't persist on a new tab. It only happens when the tab is open for quite some time, I will fill you in, if i figured out the time span. Please tell me, if you need further information, I have the profiling log, resulting in the screenshot, saved.

1. Open Threema Web.
2. Wait some time. Maybe click around, open a few chats, scroll up in chat history, but mainly - wait some time.
3. Et voilá

Potential Solution

Unfortunately I don't know the internals of Firefox' GC. (And neither do I know the internals of this code)

Your Environment

• Threema Web version: 2.2.1
• Threema App version: 4.12 Build 3000510 Google Play
• Browser name and version: Firefox 70
• Computer operating system and version: Windows 10 (1903)

[NicolasGoeddel]

This happens to me quite often because I have pinned the Threema Web tab in Firefox and I only close it if I have to restart my system which usually happens only one or two times a month.
I am running Ubuntu 19.04, the rest of my environment is the same as that of @Elsensee .