Element has memory leak (previous report was deleted)

[JeanPaulLucien]

Steps to reproduce

1. Use various Element Desktop features.

Outcome

What did you expect?

Element is not computing powers and electric energy vamp. Freedom of speech, use nickname "Element has memory leak".

What happened instead?

Element is computing powers and electric energy vamp. Banned in everyone Matrix and Element rooms and spaces for nick with reason "Help vamp".

Operating system

No response

Application version

1.11.17

How did you install the app?

No response

Homeserver

No response

Will you send logs?

No

[dbkr]

Have you found any specific things that cause the memory leak? This doesn't really contain much that we could use to investigate. #24237 is an example of a great, actionable bug report (perhaps this is the bug you're experiencing?)

[clarkf]

While looking into something completely unrelated, I noticed a stray console.error from React:

Warning: Can't perform a React state update on an unmounted component. This is
a no-op, but it indicates a memory leak in your application. To fix, cancel
all subscriptions and asynchronous tasks in the componentWillUnmount method.
RoomView@webpack-internal:///2010:321:5

I have no idea how to interpret that line number (thanks, webpack!), but I think it has something to do with one of the many subscriptions created in the constructor firing before the component is fully mounted.

I seem to recall that effectful stuff isn't supposed to happen in constructors, since React makes no guarantees about componentWillUnmount being called unless componentDidMount was called. In theory, React could create new instances of RoomView and never mount them, hence the leak.

This pattern seems to be somewhat common, e.g:

• <MessagePanel />
• <ThreadView />
• <DateSeparator />

No idea if this is the leak, but cleaning these up couldn't hurt. Worth a PR?

[t3chguy]

but cleaning these up couldn't hurt. Worth a PR?

Sure, always appreciated!

[JeanPaulLucien]

Windows 7 is no longer a supported environment - https://github.com/vector-im/element-web#supported-environments