producer_consumer_problem.rb

BUFFER_SIZE = 100
semaphore = Mutex.new

require 'thread'
queue = Thread::Queue.new

class Item
  attr_reader :data
  
  def initialize
    @data = (0...8).map { (65 + rand(26)).chr }.join
  end

  def to_s
    @data
  end
end

def consume_item(item)
  puts "Thread Consumed #{item}"
end

def produce_item
  item =  Item.new
  puts "Thread Produced #{item}"  
  item
end


# Producer
producers = []
(1..100).each do |i|
  producers << Thread.new("producer_#{i}") do
    while true
      semaphore.synchronize {
        item = produce_item
        if queue.size < BUFFER_SIZE
          queue << item          
        end
        puts "In producer #{queue.size}"        
      }
    end
  end
end


# Consumer
consumers = []
(1..100).each do |i|
  consumers << Thread.new("consumer_#{i}") do
    while true
      semaphore.synchronize {
        if queue.size > 0
          consume_item(queue.pop)          
        end
      }
    end
  end
end

[producers, consumers].flatten.each { |thr| thr.join }