Function wait 

pub fn wait<EpollFd: AsFd, Buf: Buffer<Event>>(
    epoll: EpollFd,
    event_list: Buf,
    timeout: Option<&Timespec>,
) -> Result<Buf::Output>

epoll_wait(self, events, timeout)—Waits for registered events of interest.

For each event of interest, an element is written to events.

Linux versions older than 5.11 (those that don’t support epoll_pwait2) don’t support timeouts greater than c_int::MAX milliseconds; if an unsupported timeout is passed, this function fails with io::Errno::INVAL. Enable the “linux_5_11” feature to enable the full range of timeouts.

References

• Linux
• illumos