Quick and dirty thread pool

pool.rb

class Pool
  attr_accessor :size, :jobs

  def initialize(size: 6)
    @size = size
    @jobs = Queue.new

    @pool = Array.new(@size) do |i|
      spawn_thread(i)
    end
  end

  def schedule(*args, &block)
    @jobs << [block, args]
  end

  # Throw exit in each of the threads and then wait for work to finish
  def shutdown
    @size.times { schedule { throw :exit } }
    self.join
  end

  def join
    @pool.map(&:join)
  end
  
  def block
    while @jobs.length > 0
      sleep 2
    end
  end

  private

  def spawn_thread(id)
    Thread.new do
      Thread.current[:id] = id
      catch(:exit) do
        loop do
          job, args = @jobs.pop
          job.call(*args)
        end
      end
    end
  end
end