Worker pool does not limit the number of workers created

counter.rb

require 'celluloid'

class Counter
  include Celluloid::Worker

  def count
    len = rand(1000)
    Celluloid::Actor[:min].result len
    len
  end
end

class Min
  include Celluloid
  attr_reader :min

  def result(n)
    @min ||= n
    @min = n if n < @min
  end
end

pool = Counter.pool
min = Min.new
Celluloid::Actor[:min] = min
Celluloid::Actor[:pool] = pool

puts "Number of actors: #{ Celluloid::Actor.all.length }"
50.times {
  pool.count!
}

sleep 1
puts "Number of actors: #{ Celluloid::Actor.all.length }"

100.times {
  pool.count!
}

sleep 3
puts "Number of actors: #{ Celluloid::Actor.all.length }"