CAS

CAS, or Compare-and-Swap, is a computer operation used in programming to manage shared data safely in multithreaded environments. It works by comparing a variable's current value to an expected value; if they match, CAS updates the variable to a new value atomically—that is, as a single, indivisible action. If the values don't match, it means another thread has changed the data, and CAS doesn't update. This mechanism helps improve concurrency and avoid conflicts without using locks, making programs more efficient and reducing the chances of errors when multiple processes access the same data simultaneously.