Atomic Operations¶

An atomic operation completes in a single indivisible step with respect to other threads - no intermediate state is observable. Read-modify-write operations (compare-and-swap, fetch-and-add) enable coordination without locks when contention is low.

Tension Addressed¶

Simplicity vs. Scalability

Recognizable As¶

Compare-and-swap loops, atomic counters, lock-free data structure building blocks. If you see retry loops around CAS operations, you're looking at lock-free programming using atomics.

Canonical Sources¶

Herlihy, "Wait-Free Synchronization" (1991); Herlihy & Shavit, "The Art of Multiprocessor Programming" (2008)

Transfers To¶

Distributed consensus (compare-and-swap semantics in Paxos), database optimistic concurrency, cache coherence protocols