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Dining philosophers in Ruby with Celluloid. Modified from https://gist.github.com/bugant/4984042
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require 'rubygems' | |
require 'celluloid' | |
class Waiter | |
include Celluloid | |
FORK_FREE = 0 | |
FORK_USED = 1 | |
attr_reader :philosophers | |
attr_reader :forks | |
attr_reader :eating | |
def initialize(forks) | |
@philosophers = [] | |
@eating = [] | |
@forks = Array.new(forks, FORK_FREE) | |
end | |
def welcome(philosopher) | |
@philosophers << philosopher | |
philosopher.async.think | |
end | |
def hungry(philosopher) | |
pos = @philosophers.index(philosopher) | |
left_pos = pos | |
right_pos = (pos + 1) % @forks.size | |
if @forks[left_pos] == FORK_FREE && @forks[right_pos] == FORK_FREE | |
@forks[left_pos] = FORK_USED | |
@forks[right_pos] = FORK_USED | |
@eating << philosopher | |
philosopher.async.eat | |
else | |
# it's not your turn, keep thinking | |
philosopher.async.think | |
end | |
end | |
def drop_forks(philosopher) | |
pos = @philosophers.index(philosopher) | |
left_pos = pos | |
right_pos = (pos + 1) % @forks.size | |
@forks[left_pos] = FORK_FREE | |
@forks[right_pos] = FORK_FREE | |
@eating -= [philosopher] | |
philosopher.async.think | |
end | |
end | |
class Philosopher | |
include Celluloid | |
attr_reader :name | |
attr_reader :waiter | |
def initialize(name, waiter) | |
@name = name | |
@waiter = waiter | |
waiter.async.welcome(Actor.current) | |
end | |
def think | |
puts "#{name} is thinking" | |
sleep(rand) | |
puts "#{name} gets hungry" | |
waiter.async.hungry(Actor.current) | |
end | |
def eat | |
puts "#{name} is eating" | |
sleep(rand) | |
puts "#{name} burps" | |
waiter.async.drop_forks(Actor.current) | |
end | |
end | |
names = %w{Heraclitus Aristotle Epictetus Schopenhauer Popper} | |
waiter = Waiter.new(names.size) | |
philosophers = names.map {|name| Philosopher.new(name, waiter)} | |
# The main thread is done! Sleep forever | |
sleep |
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