gevent.py

import gevent


class Pool(object):

    def __init__(self):
        self.tasks = []
        self._greenlets = []

    def apply_async(self, func, *a, **k, callback=None):
        greenlet = gevent.spawn(func, *a, **k)
        self._greenlets.append(greenlet)

        if callback:
            greenlet.link(callback)

        return greenlet
    
    def apply_all_async(self, triplets):
        return [
            self.apply_async(*t)
            for t in triplets
        ]
    
    def join(self, timeout=None):
        return [g.get() for g in gevent.wait(self._greenlets, timeout=timeout)]

    def ijoin(self, timeout=None):
        return (g.get() for g in gevent.iwait(self._greenlets, timeout=timeout))


def fake(msg, delay):
    gevent.sleep(delay)
    print("Slept {} seconds, {}".format(delay, msg))

    return delay

if __name__ == "__main__":
    p = Pool()

    #for i in range(10):
    #    p.apply_async(fake, str(i), 10 - i)

    p.apply_all_async([(fake, str(i), i) for i in range(10)])

    #l = p.join()
    #print(l)

    for r in p.ijoin():
        print(r)