Concurrent computing in Julia with actors.
Actors implements the Actor Model of computation:
An actor ... in response to a message it receives, can concurrently:
- send a finite number of messages to other actors;
- create a finite number of new actors;
- designate the behavior to be used for the next message it receives.
Actors make(s) concurrency easy to understand and reason about and integrate(s) well with Julia's multi-threading and distributed computing. It provides an API for writing reactive applications, that are:
- responsive: react to inputs and events,
- message-driven: rely on asynchronous message-passing,
- resilient: can cope with failures,
- elastic: can distribute load over multiple threads and workers.
The following example defines two behavior functions: greet and hello and spawns two actors with them. sayhello will forward a message to greeter, get a greeting string back and deliver it as a result:
julia> using Actors
julia> import Actors: spawn
julia> greet(greeting, msg) = greeting*", "*msg*"!" # a greetings server
greet (generic function with 1 method)
julia> hello(greeter, to) = request(greeter, to) # a greetings client
hello (generic function with 1 method)
julia> greeter = spawn(greet, "Hello") # start the server with a greet string
Link{Channel{Any}}(Channel{Any}(sz_max:32,sz_curr:0), 1, :default)
julia> sayhello = spawn(hello, greeter) # start the client with a link to the server
Link{Channel{Any}}(Channel{Any}(sz_max:32,sz_curr:0), 1, :default)
julia> request(sayhello, "World") # request the client
"Hello, World!"
julia> request(sayhello, "Kermit")
"Hello, Kermit!"Please look into the manual for more information and more serious examples.
Actors is part of the Julia GitHub group JuliaActors. Please join!
- Oliver Schulz (until v0.1, Oct 2017)
- Paul Bayer (rewrite since v0.1.1, Nov 2020)
MIT