gistfile1.txt

$ cat fbbench.rb 
FIBER_NUM = 503
number = ARGV.first.to_i

threads = []
for i in 1..FIBER_NUM
  threads << Fiber.new do |num|
    while true
      Fiber.yield
      if number > 0
        number -= 1
      else
        puts num
        exit 0
      end
    end
  end
  threads.last.resume(i)
end

while true
  for thread in threads
    thread.resume
  end
end

$ time ~joe/ruby-19-svn/miniruby fbbench.rb 500000
19

real	0m0.910s
user	0m0.904s
sys	0m0.008s


$ time ~joe/ruby187/miniruby fbbench.rb 500000
19

real	0m11.659s
user	0m11.537s
sys	0m0.028s


$ time ruby -I fiber18/lib -r fiber18 fbbench.rb 500000
19

real	0m22.866s
user	0m22.753s
sys	0m0.032s