{
    let _guard = fmutex::lock(path)?;

    // do mutually exclusive stuff here

} // <-- `_guard` dropped here and the lock is released

match fmutex::try_lock(path)? {
    Some(_guard) => {

        // do mutually exclusive stuff here

    } // <-- `_guard` dropped here and the lock is released

    None => {
        eprintln!("warn: the lock could not be acquired!");
    }
}