zk.py

from __future__ import print_function
import gevent
from time import sleep

def ex1():
    print('Example 1')
    # synchronous
    def f1():
        for i in xrange(10):
            print('f1', i)


    def f2():
        for i in xrange(10):
            print('f2', i)

    # Spawns f1, then f2
    jobs = [gevent.spawn(g) for g in [f1, f2]]
    gevent.joinall(jobs)
    sleep(1)

def ex2():
    print('Example 2')
    # expected to be asynch (expect each to block)
    def f1():
        for i in xrange(10):
            gevent.spawn(print, 'f1', i)

    def f2():
        for i in xrange(10):
            gevent.spawn(print, 'f2', i)

    # Spawns f1, which spawns 10 f1prints
    # Spawns f2, which spawns 10 f2prints
    jobs = [gevent.spawn(g) for g in [f1, f2]]
    # Only collects the 2 spawns in the list exp, not the 20 others
    gevent.joinall(jobs)
    sleep(1)

def ex3():
    print('Example 3')
    # yield asynchronously?
    def f1():
        jobs = []
        for i in xrange(10):
            jobs += [gevent.spawn(print, 'f1', i)]
        gevent.joinall(jobs)


    def f2():
        jobs = []
        for i in xrange(10):
            jobs += [gevent.spawn(print, 'f2', i)]
        gevent.joinall(jobs)

    jobs = [gevent.spawn(g) for g in [f1, f2]]
    gevent.joinall(jobs)
    sleep(1)

def ex4():
    print('Example 4')
    # just sleep to block
    def f1():
        for i in xrange(10):
            print('f1', i)
            gevent.sleep(0)

    def f2():
        for i in xrange(10):
            print('f2', i)
            gevent.sleep(0)

    jobs = [gevent.spawn(g) for g in [f1, f2]]
    gevent.joinall(jobs)
    sleep(1)

def ex5():
    from itertools import chain
    print('Example 5')
    def f1():
        for i in xrange(10):
            yield gevent.spawn(print, 'f1', i)

    def f2():
        for i in xrange(10):
            yield gevent.spawn(print, 'f2', i)

    jobs = [i for i in f1(), f2()]
    gevent.joinall(list(chain([list(j) for j in jobs])))
    sleep(1)

#ex1()
#ex2()
#ex3()
#ex4()
ex5()