Playing with threads and queues.

threads-and-queues.rb

#!/usr/bin/env ruby

require 'thread'

# Usage ./list-files [DIRECTORY]

WORKERS  = 5
queue    = Queue.new
@results = Queue.new
threads  = []
dir      = ARGV[0]

def process_file(filename)
  @results.push [ File.size(filename), filename ]
end

puts "Listing files in #{dir}"
Dir["#{dir}/*"].each { |filename| queue.push filename }

WORKERS.times do
  threads << Thread.new do
    process_file queue.pop until queue.empty?
  end
end

threads.each(&:join)

p @results.pop until @results.empty?