Parallel processing

parallelPprocessing.rb

require 'thread'
require 'bundler/setup'
require 'system'

from, to = Queue.new, Queue.new

item_count = rand(100) + 100
thread_count = (System::CPU.count * 4)

(1..item_count).each { |item| from.push(item) }

puts "Running with #{thread_count} threads on #{item_count} items."

thread_count.times do
  Thread.new do
    loop do
      break if from.empty?
      
      item = from.pop
      sleep(rand)
      to.push(item)
    end
  end
end

last_update = Time.now.to_f
items = []
loop do
  items << to.pop unless to.empty?
  
  current_item_count = items.length
  percent_complete = (current_item_count.to_f / item_count.to_f) * 100.0
  percent_complete = '%.2f' % percent_complete
  
  if Time.now.to_f > (last_update + 0.2) # Only update the output 5 times a second.
    last_update = Time.now.to_f
    print "#{current_item_count}/#{item_count} - #{percent_complete}% complete"
    
    if items.length == item_count
      print "\n"
      puts 'Done!'
      
      break
    else
      print "       \r"
    end
  end
  
end