A helper struct for creating, reading and closing a signalfd instance.

Important: please read the module level documentation about signal discarding before using this struct!

Examples

# use nix::sys::signalfd::*;
// Set the thread to block the SIGUSR1 signal, otherwise the default handler will be used
let mut mask = SigSet::empty();
mask.add(signal::SIGUSR1);
mask.thread_block().unwrap();

// Signals are queued up on the file descriptor
let mut sfd = SignalFd::with_flags(&mask, SfdFlags::SFD_NONBLOCK).unwrap();

match sfd.read_signal() {
    // we caught a signal
    Ok(Some(sig)) => (),
    // there were no signals waiting (only happens when the SFD_NONBLOCK flag is set,
    // otherwise the read_signal call blocks)
    Ok(None) => (),
    Err(err) => (), // some error happend
}