Another implementation of the dining philosophers in Ruby using Celluloid. This time the forks are mutexes and we don't block to acquire them.

dining02.rb

require 'rubygems'
require 'celluloid' 

class Philosopher
  include Celluloid
  def initialize(name, left_fork, right_fork)
    @name = name
    @left_fork = left_fork
    @right_fork = right_fork
    self.think
  end

  def think
    puts "Philosopher #@name is thinking..."
    sleep(rand())
    puts "Philosopher #@name is hungry..."
    self.async.dine
  end

  def dine
    if @left_fork.try_lock && @right_fork.try_lock
      puts "Philosopher #@name eats..."
      sleep(rand())
      puts "Philosopher #@name belches"

      @left_fork.unlock
      @right_fork.unlock
    else
      puts "Philosopher #@name couldn't get a fork"
    end
    self.think
  end
end

n = 5

forks = []

(1..n).each do |i|
  forks << Mutex.new
end

(1..n).each do |i|
  left_fork = forks[i-1]
  right_fork = i < n ? forks[i] : forks[0]
  Philosopher.new(i, left_fork, right_fork)
end

sleep