Fetch-and-add

In <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, the fetch-and-add (FAA) <a href="/facts/Central_processing_unit/Jxp1bqMV">CPU</a> instruction <a href="/facts/Atomic_(computer_science)/u3pnNCvs">atomically</a> increments the contents of a <a href="/facts/Memory_location/7EsUmbea">memory location</a> by a specified value.
That is, fetch-and-add performs the following operation: increment the value at address x by a, where x is a memory location and a is some value, and return the original value at x.
in such a way that if this operation is executed by one process in a <a href="/facts/Concurrent_computing/yVzQBPr9">concurrent</a> system, no other process will ever see an intermediate result.
Fetch-and-add can be used to implement <a href="/facts/Concurrency_control/JWnmhVd5">concurrency control</a> structures such as <a href="/facts/Mutual_exclusion/1dwvCxDW">mutex locks</a> and <a href="/facts/Semaphore_(programming)/BrE1W4Je">semaphores</a>.

Fetch-and-add open-in-new

Fetch-and-add