Rubygoes to

@elise_huard Rubykaigi 2011

Ruby,ハリウッドに行く

Contextコンテキスト

“Concurrency is hard”並行処理は難しい

“Shared and Mutable State”状態の共有と変更

“Why Bother?”だからなんだっていうの？

Actors アクターズ

“Actor Model” (1973)アクターモデル (1973)

“No Global State””グローバル状態がない”

“Actors””アクター”

“Partial Order of Execution””部分実行”

非同期Mutableメッセージ

アクター

独立したMutable状態

“Sleeping Barber”居眠り床屋問題

Barber BarberShop

The universe

customer X

customers waiting

wake up

sleeping/cutting

customers?customer X

no

理容師

眠る／理髪する

床屋

顧客が待っている

一般世界

Rubyルビー

“Rubinius Actors”@mentalguy

“Revactor”@bascule

“Celluloid”

Text

class Barber include Celluloid::Actor attr_accessor :status

def initialize(shop) @shop = shop end

def cut_customer(name) puts " cutting customer #{name}" sleep(rand(5)) accident = rand(2) if accident puts " finished cutting #{name}" else puts " *** whoops, chopped #{name}'s head off ***" end shop.customer_leaves! end(...)end

Text

class Shop include Celluloid::Actor

def initialize @barber = Barber.new(self) @chairs = [] puts "lights on ..." end

def waiting_line @chairs.size end

def new_customer(name) puts " customer arriving: #{name}" if waiting_line > 3 puts "*** sorry, #{name}, no room ***" else @chairs << name @barber.cut_customer!(name) end end

def customer_leaves @chairs.shift endend

Text

shop = Shop.new['jack', 'john', 'henry', 'tom', 'bob'].each do |customer| shop.new_customer!(customer)endshop.report

“CRuby”

Foreign lands他言語

“Erlang”

%% shop %%barber_shop() -> io:format("lights on ... ~n"), ShopPid = self(), BarberPid = spawn(fun() -> barber(ShopPid) end), barber_shop_in_business(BarberPid, []).

barber_shop_in_business(BarberPid, CustomersInChairs) -> receive {cut, Customer} -> % pop customer from list when hair is being cut remove_customer(BarberPid, CustomersInChairs, Customer); barbercheck -> respond_to_barber(BarberPid, CustomersInChairs); Customer -> io:format("~p arrives~n",[Customer]), % should check the number of customers waiting first % if all full: customer turned away add_customer_if_available(BarberPid, CustomersInChairs, Customer) end.

Text

%% barber %%barber(ShopPid) -> ShopPid ! barbercheck, receive wakeup -> barber(ShopPid); {customer, Customer} -> cut(ShopPid, Customer), barber(ShopPid) end. cut(ShopPid, Name) -> io:format("cutting ~p~n", [Name]), % take customer -> can be removed from waiting chairs ShopPid ! {cut, Name}, timer:sleep(random:uniform(10000)), io:format("finished cutting: ~p~n", [Name]).

Text

scenario() -> ShopPid = start_shop(), % send customers to the shop ShopPid ! 'john', ShopPid ! 'joe', timer:sleep(20000), ShopPid ! 'kevin', ShopPid ! 'richard', main_end.

Text

http://vimeo.com/26560141

“Elixir”

Text

object Shop def initialize shop_pid = Process.current barber_pid = Process.spawn -> Barber.loop(shop_pid) @('barber_pid: barber_pid, 'shop_pid: shop_pid) end

def loop(customers_in_chairs) IO.puts "shop loop #{customers_in_chairs}" receive match {'cut, customer} if customers_in_chairs.include?(customer) loop(customers_in_chairs.delete(customer)) else loop(customers_in_chairs) end match 'barbercheck IO.puts "barber checking ..." respond_to_barber(customers_in_chairs) match {'customer, customer} IO.puts("new customer #{customer}") add_customer(customers_in_chairs, customer) end end (...)end

Text

module Barber def loop(shop_pid) shop_pid <- 'barbercheck receive match 'wakeup IO.puts "wakeup" loop(shop_pid) match {'customer, customer} cut_hair(shop_pid, customer) loop(shop_pid) end end

def cut_hair(shop_pid, customer) IO.puts "cutting customer #{customer}" shop_pid <- {'cut, customer} IO.puts "finished cutting customer #{customer}" endend

Text

pid = Process.spawn -> Shop.new.loop([])IO.puts pidpid <- {'customer, "jack"}pid <- {'customer, "bob"}

“Scala”

Text

class BarberShop extends Actor { var barber: ActorRef = null var customersInChairs = List[Customer]()

override def preStart() { barber = Actor.actorOf(new Barber(self)).start() }

def receive = { case Customer(name) => if (customersInChairs.length >= 3) { println("sorry, no room for " + name) } else { customersInChairs = customersInChairs :+ Customer(name) barber ! WakeUp } case Cut(name) => customersInChairs = customersInChairs.tail case BarberCheck => // send first customer barber ! customersInChairs.head }}

Text

class Barber(val shop: ActorRef) extends Actor { def cut(name: String) = { shop ! Cut(name) } def receive = { case WakeUp => shop ! BarberCheck case Customer(name) => cut(name) shop ! BarberCheck }}

Text

package sleepingBarber

import akka.actor.{Actor, ActorRef, ActorRegistry}import Actor._import akka.actor.Actor.actorOf

/* messages classes */sealed trait BarberMessagecase class Customer(name: String) extends BarberMessagecase class Cut(name: String) extends BarberMessagecase class BarberCheck() extends BarberMessagecase class NoCustomers() extends BarberMessagecase class WakeUp() extends BarberMessage

object SleepingBarber { def main(args: Array[String]) : Unit = { val barberShop = Actor.actorOf[BarberShop].start() barberShop ! Customer("John") barberShop ! Customer("Jack") barberShop ! Customer("Arthur") Actor.registry.shutdownAll }}

“JRuby”

Caveatはまりどころ

“easy to understand”“簡単に理解できる”

“real encapsulation””本物”

“highly decentralized””高度に分散化された”

“clear separation of parallel components”“境界が明らかな時だけ”

“livelocks - deadlocks still possible”“ライブロック-でもデッドロックは依然として起こりえる”

“Concurrency Primitives”並行性のためのプリミティブ

Epilogueエピローグ

“Time to control shared state?”shared stateをコントロール

するための時間

“Better Concurrency Primitives

in stdlib?”並行性のためのより良いプリミティブを

スタンダードライブラリーに

Speakerスピーカー

@elise_huardTranslation井上　真

Conferenceカンファレンス

Ruby Kaigi 2011

Sponsorスポンサー

Forward

Pictures写真

Sherlock Jr (1924)Safety Last (1923)

A Woman of Affairs (1928)Mysteries of a Barbershop (1923)

The Doll (1919)Intolerance (1926)Metropolis (1927)

He Who Gets Slapped (1924)Laughing Gravy (1931)

Documentationドキュメンテーション

http://www.delicious.com/elisehuard/concurrency

終わりThe End

@@@elise_huardTranslation: 井上　真

The End

Pictures写真

Sherlock Jr (1924)Safety Last (1923)

A Woman of Affairs (1928)Mysteries of a Barbershop (1923)

The Doll (1919)Intolerance (1926)Metropolis (1927)

He Who Gets Slapped (1924)Laughing Gravy (1931)

Documentationドキュメンテーション

http://www.delicious.com/elisehuard/concurrency

ご清聴ありがとうございました !

終わりThe End

@@@elise_huardTranslation: 井上　真