Parallel Processing in Production Environment

Bank restaurant that I have visited today and believe to be one of the largest restaurants (seat-wise) in Helsinki had elevated customer self-service to unparalleled (or rather super-paralleled) heights. The single mutex (cashiers) is locked only once and only to pay for food and grab fork and knife. The rest of IO (choosing and loading food) was totally asynchronous and evenly distributed between serving tables. Each thread (customer) was free to perform operations in whatever order it pleased, so you could always choose the least busy table. The throughput of this system was truly amazing! Any accumulated queues were dissolving in seconds. It was a beauty to behold.