http://stackoverflow.com/questions/9247641/throughput-differences-when-using-coroutines-vs-threading

concurrency.py

#!/usr/bin/env python
concurrency_impl = 'gevent' # single process, single thread
##concurrency_impl = 'threading' # single process, multiple threads
##concurrency_impl = 'multiprocessing' # multiple processes

if concurrency_impl == 'gevent':
    import gevent.monkey; gevent.monkey.patch_all()

import logging
import time
import random
from itertools import count, islice

info = logging.info

if concurrency_impl in ['gevent', 'threading']:
    from Queue import Queue as JoinableQueue
    from threading import Thread
if concurrency_impl == 'multiprocessing':
    from multiprocessing import Process as Thread, JoinableQueue


def do_work(wid, value):
    time.sleep(random.randint(0,2))
    info("%d Task %s done" % (wid, value))


def worker(wid, q):
    while True:
        item = q.get()
        try:
            info("%d Got item %s" % (wid, item))
            do_work(wid, item)
        finally:
            q.task_done()
            info("%d Done item %s" % (wid, item))


def producer(pid, q):
    for item in iter(lambda: random.randint(1, 11), 10):
        time.sleep(.1) # simulate a green blocking call that yields control
        info("%d Added item %s" % (pid, item))
        q.put(item)
    info("%d Signal Received" % (pid,))


def main():
    logging.basicConfig(level=logging.INFO,
                        format="%(asctime)s %(process)d %(message)s")

    q = JoinableQueue()
    it = count(1)
    producers = [Thread(target=producer, args=(i, q)) for i in islice(it, 2)]
    workers = [Thread(target=worker, args=(i, q)) for i in islice(it, 4)]
    for t in producers+workers:
        t.daemon = True
        t.start()

    for t in producers: t.join() # put items in the queue
    q.join() # wait while it is empty
    # exit main thread (daemon workers die at this point)

if __name__=="__main__":    
   main()