macOS: Typing indicators cause high CPU & GPU usage

[Shnub]

• I have searched open and closed issues for duplicates

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Bug Description

On both installations of macOS that I'm running Signal Desktop on (one 10.14.6 on Intel and one 11.2.2 on Apple ARM), CPU and GPU usage is very low when Signal is idle, but whenever a typing indicator is displayed, it jumps to curiously high values. This happens always; the indicator is never displayed without processor usage spiking. It doesn't matter whether the indicator appears in a visible conversation or just in the conversation list.

Crucially, this happens not only when the app is visible, but even when it is hidden or the window closed. Consequently, energy usage is now much higher than it used to be, dependent of course on how often and how long people compose messages.

This behavior started only recently, though unfortunately I can't say when exactly. It certainly wasn't an issue a year ago.

Steps to Reproduce

1. Observe processor usage while Signal is idle.
2. Wait till someone types a message and a typing indicator is displayed. (Signal window can be open, hidden, or closed.)

Actual Result:

High CPU and GPU usage.

Expected Result:

Processor usage not much higher than in idle state.

Screenshots

Signal processor usage when idle:

Signal processor usage while typing indicator is visible (no other discernible activity):

Platform Info

Signal Desktop Version: 1.40.1

Operating System: macOS 10.14.6 & 11.2.2

Linked Device Version: iOS 13.7

Signal Version on Linked Device: 5.5.0.18

Link to Debug Log

https://debuglogs.org/b79ff08e7f9c01cd844475995f85b19dcd8016caa8508dc308dfe658af531053

Wasn't quite fast enough, but scroll up to time 22:01:29, which should correspond to the time the problem occurred according to the screenshot filenames above (one hour difference likely Central European vs. Greenwich Time). At 22:02:02, the problem is gone again.

[sampumon]

For me, on a 2014 MacBook Air i7, cpu usage is so high that I know someone is typing when the fan ramps up 🌪️

Curiously WindowServer goes most berserk from this, hitting 80~90% cpu usage (normally less than 10%).

[scottnonnenberg-signal]

The CSS involved in animating a typing indicator is here:

Signal-Desktop/stylesheets/_modules.scss

Lines 5387 to 5436 in db27a36

	@keyframes typing-animation-first {
	0% {
	opacity: 0.4;
	}
	20% {
	transform: scale(1.3);
	opacity: 1;
	}
	40% {
	opacity: 0.4;
	}
	}
	@keyframes typing-animation-second {
	10% {
	opacity: 0.4;
	}
	30% {
	transform: scale(1.3);
	opacity: 1;
	}
	50% {
	opacity: 0.4;
	}
	}
	@keyframes typing-animation-third {
	20% {
	opacity: 0.4;
	}
	40% {
	transform: scale(1.3);
	opacity: 1;
	}
	60% {
	opacity: 0.4;
	}
	}
	.module-typing-animation__dot--first {
	animation: typing-animation-first 1600ms ease infinite;
	}
	.module-typing-animation__dot--second {
	animation: typing-animation-second 1600ms ease infinite;
	}
	.module-typing-animation__dot--third {
	animation: typing-animation-third 1600ms ease infinite;
	}

Really doesn't seem like it should cause the behavior you're seeing, but perhaps there's something we could do to massage that a bit? If anyone would like to dig in, that would be appreciated! We need your help because we can't reproduce this on our machines!

[sampumon]

It does not seem to be the css, but javascript/react. I'm getting 5fps frames and lots of red-striped tasks on dev tools profiler. Exactly where this happens gets a bit lost in call stacks…

would this saved profile help you? It starts when typing indicator active, and ends few seconds after. I turned screenshots off, so no sensitive information..? 🤔

signal-desktop-typing-profile.zip

[scottnonnenberg-signal]

@sampumon Thanks for that profile. What exact version of the app were you running with that log? Because it includes references to specific source file lines, that information would really help.

[sampumon]

@scottnonnenberg oh yeah sorry, latest non-beta that is v1.40.1 💙

[sampumon]

Oh I just realised that this happens also when Signal window is closed 🦉

[Shnub]

Oh I just realised that this happens also when Signal window is closed 🦉

Yes, visible, hidden or closed window makes no difference. Also, the typing animation need not even be visible when the window is open; if you start a search for a conversation where the other party is not typing (so that the standard conversation list is not shown and thus no typing indicators there), then let someone from another conversation type (so there is also no typing indicator at the end of the active conversation), processor usage still spikes.

Also, I can confirm that the Window Server process is most affected, with CPU usage even higher than the GPU helper process.

Lastly, just to make sure, I disabled typing indicators on my mobile device and after the new setting had propagated to Signal Desktop, the problem was gone. Re-enabled the option and it was right back again.

[ardarandir]

Is this issue still persisting under new Signal 5.0.0? Otherwise this bug could be closed.

[sampumon]

Is still present on Signal 5.0.0, and also I upgraded to bigSUR 11.2.3.

And on 5.0.0, Signal Helper (Renderer) is using around 4% CPU all the time, as reported on beta thread and #5192.

[Shnub]

Confirmed, behavior is unchanged vs. 1.40.1.

[MrEbbinghaus]

Still happening with Signal 5.3.0 on macOS 11.4 (20F71)

[IngaFeick]

Still happening on macOS 11.1 with 5.5.0.
In my case the problem started appearing just very recently, with the latest Signal update that I ran a couple of days ago.