SynchronousQueue - Producer-Consumer

gistfile1.rb

import java.util.concurrent.SynchronousQueue

module ProducerConsumer
  def self.do_work
    trap :TERM , -> { Queue.shutdown! }
    trap :INT  , -> { Queue.shutdown! }

    threads = [
      Producer.new.tap{ |o| o.start },
      Consumer.new.tap{ |o| o.start }
    ]

    threads.each &:join
    puts 'Buh Bye'
  end

  module Queue
    @running = true

    def self.put(work)
      _queue.put work if running?
    end

    def self.take
      _queue.take if running?
    end

    def self.running?
      @running
    end

    def self.shutdown!
      puts 'shutting down'
      @running = false
      drain
    end

    private

    def self._queue
      @queue ||= SynchronousQueue.new
    end

    def self.drain
      _queue.take
    end
  end

  class Producer < java.lang.Thread
    def run
      while Queue.running? do
        puts 'produce'
        Queue.put 'work'
        sleep 0.1
      end
    end
  end

  class Consumer < java.lang.Thread
    def run
      while Queue.running? do
        puts "working on #{Queue.take}"
        sleep 1
      end
    end
  end
end

ProducerConsumer.do_work