Riot is an actor-model multi-core scheduler for OCaml 5. It brings Erlang-style concurrency to the language, where lighweight process communicate via message passing
An actor-model multi-core scheduler for OCaml 5.
open Riot type Message.t += Hello_world let () = Riot.run @@ fun () -> let pid = spawn (fun () -> match receive () with | Hello_world -> Logger.info (fun f -> f "hello world from %a!" Pid.pp (self ()))) in send pid Hello_world
At its core Riot aims to offer:
Automatic multi-core scheduling – when you spawn a new Riot process, it will automatically get allocated on a random scheduler.
Lightweight processes – spawn 10 or 10,000 processes as you see fit.
Fast, type-safe message passing
Selective receive expressions – when receiving messages, you can skim through a process mailbox to consume them in arbitrary order.
Process links and monitors to keep track of the lifecycle of processes
Riot also includes:
Supervisors to build process hierarchies
Logging and Telemetry designed to be multicore friendly
an Application interface to orchestrate startup/shutdown of systems
Generic Servers for designing encapsulated services like with Elixir's GenServer
At the same time, there's a few things that Riot is not, and does not aim to be.
Primarily, Riot is not a full port of the Erlang VM and it won't support several of its use-cases, like:
supporting Erlang or Elixir bytecode
hot-code reloading in live applications
function-call level tracing in live applications
git clone https://github.com/leostera/riot cd riot opam install .
After that, you can use any of the examples as a base for your app, and run them:
dune exec ./my_app.exe
Riot is the continuation of the work I started with Caramel, an Erlang-backend for the OCaml compiler.
It was heavily inspired by eio by the OCaml Multicore team and miou by Calascibetta Romain and the Robur team, as I learned more about Algebraic Effects. In particular the
Proc_state is based on the
State module in Miou.