Based on this post, when you drop a monoio TcpListener nothing happens. If there is an accept inflight, when it completes the reactor wakes your task, which ignores the wake up and goes back to sleep. INSTEAD when you drop the TcpListener it should cancel interest in this event with the reactor, and when the event completes the reactor should clean up the state for the complete event (which means closing the newly open file descriptor in this case).

Does this involve synchronization? Yes! Surprise surprise, when you share state between concurrent processes (whether they be tasks, threads, processes, or userspace and the kernel) you need some form of synchronization. When you say things like “Rust’s facilities to prevent race conditions [are] synchronizations tools and not part of async” you are speaking nonsense, because async Rust in all its forms are built on these synchronization primitives, whether they be atomic variables or system mutex’s or what have you.

To the moderators (dang), do people get to keep their account here just because they're a "famous" poster despite writing the way they're doing all over this post? I'm assuming other posters have been banned for substantially less aggressive behaviour...