Method lock_irq

Locks the [`Mutex`] and returns a IRQ guard that permits access to the inner data and disables interrupts while the lock is held. The returned value may be dereferenced for data access and the lock will be dropped and interrupts will be re-enabled when the guard falls out of scope. Deadlocks occur if a thread tries to acquire a lock that will never become free. Thus, locking interrupts is useful

(&self)