Hanging application when opening some ewebsock connections

[Kerollmops]

Hi,

My egui application completly hang sometimes, it looks like it is related to cloning/requesting a repaint from the Context.
My project can be found on this repository at this exact commit, it looks like it happens only when multiple ewebsock are opened at the same time.

Here is a backtrace of all threads and we can see that it hang when a request_repaint was called (Context::write).
Hanging riemann-egui-dash.txt

[emilk]

Probably a double-locking of a mutex in Context.

Try running in debug (it catches some problems), or use the new deadlock_detection feature (#1619) or try #1732