How Main App schedule run right after render app Extract Stage?

[younggam]

According to update fn in App

bevy/crates/bevy_app/src/app.rs

Lines 145 to 148 in a6f6a8f

	self.schedule.run(&mut self.world);
	for sub_app in self.sub_apps.values_mut() {
	(sub_app.runner)(&mut self.world, &mut sub_app.app);
	}

It and its sub apps use mutable reference of World that can't be used simultaneously in neither single or multi thread.
But, Bevy offically says that can happen after Extract Stage.
What magic used inner?

[younggam]

I tried to examine this own by "trace-chrome" feature
and here is the result

As you can see, it is clear that render subapp is highly tied with main app unlike introduced below.

https://bevyengine.org/news/bevy-0-6/#pipelined-rendering-extract-prepare-queue-render

I guess this news is outdated since higher version of bevy changed render polices

[mockersf]

In that blog post, there is also:

As a quick callout, pipelined rendering doesn't actually happen in parallel yet.

It has not been done yet because... that's not the biggest thing to work on for now, and time is limited...

[younggam]

wait my eye issue