require 'pty'

$arg = ARGV[0] ? ARGV[0].to_i : 10000

if $arg < 10
  puts "Hang should be very probable. Try again if it doesn't hang"
else
  puts "$arg is #{$arg} which is too large. Pass anything from 1 to 10 to trigger ruby hang"
end

loop do
  pid = nil

  info = []

  4.times do
    r = w = p = nil 
    PTY.spawn("ruby -e '(4000000/#{$arg}).times {}; sleep 0.2; puts 1'") do |rd,wr,pd|
      r,w,p = rd,wr,pd
    end
    info << [r,w,p]
  end

  info.each do |r,w,*e|
    r.gets
    w.close
    r.close
  end

  print "."
  STDOUT.flush
end