What asynchronous runtime does bevy use for concurrency?

[Bjohnson131]

Pretty much as it says on the tin.

I don't see the common rust asynchronous runtimes in cargo.toml (tokio, rayon, futures), yet on the front page of the bevy website, Bevy advertises "Lock-Free Parallel Scheduler", which would indicate that an asynchronous runtime is used for processing. What runtime does Bevy use for concurrency?

[killercup]

tl;dr Bevy supports regular futures and parallel iterators. It does not depend on a "full" async I/O lib like tokio.

Not an expert on the topic, just looking at the bevy_task crate. It depends on these:

bevy/crates/bevy_tasks/Cargo.toml

Lines 16 to 20 in 0566e73

	futures-lite = "1.4.0"
	async-executor = "1.3.0"
	async-channel = "1.4.2"
	async-task = "4.2.0"
	concurrent-queue = "2.0.0"

These are the same crates used by smol, a small alternative to tokio. The main feature is that bevy_tasks has a thread pool to run futures/tasks. The async compute example shows one way of using it, another is shown in the parallel query example (this is almost like rayon but using the bevy_task thread pool).