Function lock_or_abort 

pub fn lock_or_abort<'a, T: ?Sized>(
    mutex: &'a Mutex<T>,
    what: &'static str,
) -> MutexGuard<'a, T>

Lock mutex, named what: state the whole process shares. A panic while it was held may have left it half-changed, and nothing narrower than the process can be failed for it, so the process ends.