Call SkiaLayerComponent.onComposeInvalidation() only from the event dispatch thread

[m-sasha]

Currently, ComposeSceneMediator.onComposeInvalidation() calls SkiaLayerComponent.onComposeInvalidation() directly. However, ComposeSceneMediator.onComposeInvalidation() is not guaranteed to be called from the event dispatch thread, whereas SkiaLayerComponent.onComposeInvalidation() must be called from the event dispatch thread. When it's called from another thread, it throws an exception.

RelNote: Fix crash when modifying Compose state from a non-UI thread.

Proposed Changes

Make ComposeSceneMediator.onComposeInvalidation() call SkiaLayerComponent.onComposeInvalidation() on the event dispatch thread only.

Testing

Test: Added a unit test, and also tested manually with the following:

var value by mutableStateOf(0)

fun main() = singleWindowApplication {
    val textMeasurer = rememberTextMeasurer()
    Canvas(Modifier.size(100.dp)) {
        drawText(textMeasurer, "$value")
    }
    LaunchedEffect(Unit) {
        withContext(Dispatchers.IO) {
            for (i in 1..5_000) {
                value = i
                Snapshot.sendApplyNotifications()
                delay((1..20).random().toLong())
            }
        }
    }
}

Issues Fixed

Fixes: JetBrains/compose-multiplatform#4546