Thread pool taken from http://burgestrand.se/code/ruby-thread-pool/

pool.rb

require 'thread' #taken from http://burgestrand.se/code/ruby-thread-pool/

class Pool
  def initialize(size)
    @size=size
    @jobs = Queue.new
    @pool = Array.new(@size) do |i|
      Thread.new do
        Thread.current[:id] = i
        catch(:exit) do
          loop do
            job, args = @jobs.pop
            job.call(*args)
          end
        end
      end
    end
  end
  
  def schedule(*args, &block)
    @jobs << [block, args]
  end
  
  def shutdown
    @size.times do
      schedule {throw :exit }
    end
    @pool.map(&:join)
  end
end