Using `ComposeScene`s with anything but `MainUIDispatcher` results in a deadlock about compose-multiplatform HOT 19 OPEN

Unfortunately this is not currently a supported use-case.

We tried to allow concurrent use of ComposeScene here, but ran into limitations (mentioned in that ticket).

It's possible that we have since introduced our own, additional, limitations, since we've stopped trying to support concurrent use of ComposeScene ourselves.

from compose-multiplatform.

Hasn't the linked issue been caused by multiple threads being used for the same scene due to Dispatchers.Unconfined being the default context for ImageComposeScene? If yes, then this is not what I want. I do not want to use the same scene concurrently, but multiple scenes each on their own separate (but only that single) thread.

from compose-multiplatform.

No, it's about using multiple scenes concurrently.

Why do you need to use multiple ComposeScenes each in their own thread?

from compose-multiplatform.

I have been using multiple scenes for a server-side GUI, where the server handles multiple users at once.

The performance degraded severely now that everything has to use MainUIDispatcher.

from compose-multiplatform.

Can you try using a single-thread dispatcher instead of Dispatchers.Default.limitedParallelism(1), e.g.

Executors.newSingleThreadExecutor().asCoroutineDispatcher()

?

from compose-multiplatform.

Yes, I tried that as well - it results in the same deadlock between that single-thread and the AWT event queue.

from compose-multiplatform.

Also, does this mean that using Compose to render into GLFW windows (for example using LWJGL) is unsupported now as well? (you have to use the glfw thread there, which clashes with the requirement for MainUIDispatcher)

from compose-multiplatform.