Note, this post is written against the 2.0.1 version of
Erlang comes with a rich set of small concurrency primitives to make handling and manipulating state easier. The most generic of the frameworks is the
gen_server which is also the most commonly used. A
gen_server provides a way to control state over multiple requests. It serializes operations and handles both synchronous and asynchronous communication with clients. The strength of a
gen_server is the ability to create multiple, lightweight, servers inside an application where each operation inside of it runs in serial but individually the
gen_servers run concurrently.
While it is not possible to provide all of the Erlang semantics in Ocaml, we can create something roughly analogous. We can also get some properties that Erlang can not give us. In particular, the implementation of
gen_server provided here: