Function poll 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn poll(
    fds: *mut pollfd,
    nfds: nfds_t,
    timeout: c_int,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/poll.html.

Provides applications with a mechanism for multiplexing input/output over a set of file descriptors.

• The timeout parameter represents milliseconds.
• A timeout of -1 is equivalent to passing a null pointer for tmo_p to ppoll.
• poll should behave equivalent to ppoll with a null pointer for sigmask.

Note: Uses epoll internally.