协程处理异步例子

# -*- coding: utf-8 -*-

import thread
import time

def real_add(a, b, cb):
    def add():
        print("[LOG] count add (%d + %d)...." % (a, b))
        time.sleep(3)
        c = a + b
        print("[LOG] count add done (%d + %d = %d)." % (a, b, c))
        cb(c)
    thread.start_new_thread(add, ())

def add_task(a, b):
    def _add_task(cb):
        real_add(a, b, cb)
    return _add_task
###############################
def my_task():
    print("before task")
    c = yield add_task(1, 2)
    print("middle task c: %d" % c)
    d = yield add_task(c, 10)
    print("end task %d" % d)

def start_task(gen):
    def cb(result):
        try:
            task = gen.send(result)
        except StopIteration:
            return
        task(cb)
    cb(None)

start_task(my_task())

从 http://code.activestate.com/recipes/577129-run-asynchronous-tasks-using-coroutines/ 学习来的