Thread IO in Ruby

threadio.rb

module ThreadIO
	def ThreadIO.puts(s)
		@@semaphore ||= Mutex.new
		@@semaphore.synchronize do
			STDOUT.puts s
		end
		Thread.pass
	end
end

threads =[]
threads << Thread.new { 30.times { ThreadIO::puts "A" } }
threads << Thread.new { 30.times { ThreadIO::puts "B" } }
threads << Thread.new { 30.times { ThreadIO::puts "C" } }

threads.each do |thread|
	thread.join
end