Rust provides a mechanism for spawning lightweight tasks via the spawn function, the argument of this function is an owned closure named proc.

{tasks.play}

These tasks will be scheduled by the Rust runtime and the order of execution of these tasks will be non-deterministic.

(By default, Rust uses its native runtime, which maps each Rust task to a native thread. Rust also provides a green runtime that provides green threads and maps M Rust tasks to N native threads.)