Lamport's bakery algorithm

Lamport's bakery algorithm is a mutual exclusion algorithm devised by the computer scientist Leslie Lamport as part of his long study of the formal correctness of concurrent systems. It addresses a common hazard in programs that run several threads at once: when two or more threads write to the same memory location, or when one thread reads a location before another has finished writing it, data can be corrupted. The bakery algorithm is one of many mutual exclusion algorithms designed to keep concurrent threads from entering critical sections of code at the same time, which removes that risk of corruption and improves the safe use of shared resources. In computing it is taught as a classic example of how threads can coordinate access to shared state using only ordinary shared memory.