in rust, there is no built-in runtime, so it depends on which one you are using. the runtime (e.g. tokio) is responsible for polling the future. for network io

in rust, there is no built-in runtime, so it depends on which one you are using. the runtime (e.g. tokio) is responsible for polling the future. for network io, behind the scenes this is most likely utilizing epoll system calls. epoll mitigates context switch problem in a few ways, mostly because there is only one stack context to notify about new io events, instead of many.