Everyone is answering your question mentioning the Clojure STM, but I'd point out the nowadays most concurrency problems in Clojure can be, and are solved witho

Everyone is answering your question mentioning the Clojure STM, but I'd point out the nowadays most concurrency problems in Clojure can be, and are solved without touching the STM. Immutable and persistent collections, atoms, agents and more can all be used outside the STM and produce the right results.