thread-pool.rb

# worker
require 'thread'

queue = Queue.new
threads = []

puts 'create workers'

10.times do |n|
  threads << Thread.new(n) do |c|
    # each worker waits before starting
    sleep 1

    loop do
      a = queue.pop
      if a.nil?
        puts "#{c} quitting"
        break
      else
        puts "#{c} #{a}"
        # simulate work
        sleep(rand() * 0.2)
      end
    end
  end
end

puts 'add work'
start = Time.now
190.times do |n|
  queue.push(start + n)
end

puts 'add work stop signal (nil value)'
threads.size.times { queue.push(nil) }

puts 'wait for each thread to complete'
threads.each { |t| t.join }

puts "DONE"