gevent-whispers.py

from gevent import spawn
from gevent.queue import Queue

def whisper(left, right):
  left.put(right.get() + 1)

def main():
  n = 100000
  leftmost = Queue()
  left, right = None, leftmost
  for _ in range(n):
    left, right = right, Queue()
    spawn(whisper, left, right)
  right.put(1)
  print leftmost.get()

if __name__ == '__main__':
  main()