We have designed, implemented, and evaluated AtomCaml, an extension to Objective Caml that provides a synchronization primitive for atomic (transactional) execution of code. A first-class primitive function of type (unit->'a)->'a evaluates its argument (which may call other functions, even external C functions) as though no other thread has interleaved execution. Our design ensures fair scheduling and obstruction-freedom. Our implementation extends the Objective Caml bytecode compiler and run-time system to support atomicity. A logging-and-rollback approach lets us undo uncompleted atomic blocks upon thread pre-emption, and retry them when the thread is rescheduled. The mostly functional nature of the Caml language and the Objective Caml implementation's commitment to a uniprocessor execution model (i.e., threads are interleaved, not executed simultaneously) allow particularly efficient logging.
JoCaml is Objective Caml plus (&) the join calculus, that is, OCaml extended for concurrent and distributed programming. The new JoCaml is a re-implementation of the now unmaintained JoCaml by Fabrice Le Fessant. With respect to this previous implementation, main changes are: * Numerous syntax changes, we believe the new syntax to be cleaner. * Disparition of mobility features, sacrified for the sake of OCaml compatibility. * Much better compatibility with Objective Caml. o Source compatibility is about 99%, there are three new keywords (def, reply and spawn) ; or and & should definitely not be used as boolean operators. o Binary compatibility for matching versions.