designing an actor model game architecture with pony
TRANSCRIPT
Designing an Actor Model Game Architecture with PonyNick Prühs
Pony
• object-oriented
• actor-model
• capabilities-secure
Pony
• object-oriented
• actor-model
• capabilities-secure
Hello world!
actor Mainnew create(env: Env) =>
env.out.print("Hello, world!")
Actors in Pony
• Similar to classes
• Can have asynchronous functions called behaviours
• Bodies of behaviours will execute at some indeterminate time in the
future
• All behaviours always return the receiver
They can't return something they calculate (since they haven't
run yet)
Returning the receiver is a convenience to allow chaining calls
on the receiver
Behaviours
actor Aardvark
let name: String
var _hunger_level: U64 = 0
new create(name': String) =>
name = name'
be eat(amount: U64) =>
_hunger_level = _hunger_level - amount.min(_hunger_level)
“Here we have an Aardvark that can eat asynchronously.
Clever Aardvark.”
Pony
• object-oriented
• actor-model
• capabilities-secure
Reference Capabilities
Remember const in C++?
Reference Capabilities
Remember const in C++?
Awesome, right?
Reference Capabilities
• ref – mutable
• val - immutable
• iso - no one else can read or write
… plus three more.
Reference Capabilities
actor FileStream is OutStream
let _file: File
new create(file: File iso) =>
_file = consume file
be write(data: ByteSeq) =>
_file.write(data)
Pony
• type safe
• memory safe
• exception safe
• data-race free
• deadlock free
PonyGame Architecture
DEMO
Code publicly available at
https://github.com/npruehs/pony-game
References
• S. Clebsch, Pony: Co-Designing a Type System and a Runtime.Microsoft Research, Cambridge, 2016.
• S. T Allen, S. Clebsch, S. Blessing, A. McNeil et al., Pony Tutorial.http://tutorial.ponylang.org, 2016.
• S. Clebsch, S. Blessing, J. Franco, S. Drossopoulou, Ownership and Reference Counting based Garbage Collection in the Actor World.Causality Ltd. and Imperial College London, 2015.
• S. Clebsch, S. Drossopoulou, Fully Concurrent Garbage Collection of Actors on Many-Core Machines. OOPSLA 2013.
• S. Clebsch, S. Drossopoulou, S. Blessing, A. McNeil, Deny Capabilities for Safe, Fast Actors. Causality Ltd. and Imperial College London.
