gevent模块学习(四)

gevent.spawn会对传入的子任务集合进行调度，gevent.joinall 方法会阻塞当前程序，除非所有的greenlet都执行完毕，才会退出程序

公有方法
gevent.spawn(cls, *args, **kwargs)	创建一个Greenlet对象,其实调用的是Greenlet.spawn(需要from gevent import Greenlet),返回greenlet对象
gevent.joinall(greenlets, timeout=None, raise_error=False, count=None)	等待所有greenlets全部执行完毕, greenlets为序列,timeout为超时计时器对象,返回执行完毕未出错的的greenlet序列
greenlet
g.join()	等待此协程执行完毕后

 

注意: 多条gevent.spawn(cls, *args, **kwargs).join()语句即使为阻塞调用也不会协程式调用,因为生成的Greenlet对象执行完就消失,所有要实现协程式调用可通过gevent.joinall(greenlets, timeout=None, raise_error=False, count=None)或是赋值到一变量后再对此对象调用.join(),其中一个特殊的方式就是for循环调用将隐式的赋值对象调用,会自动变为协程式运行.

# coding:utf-8

import gevent
import random

def task(pid):
    gevent.sleep(random.randint(0,2)*0.001)
    print('task %s done'%pid)

def synchronous():
    for i in range(1, 10):
        task(i)

def asynchronous():

    threads = [gevent.spawn(task, i) for i in xrange(10)]
    # print(threads)
    # spawn将task函数封装到greenlet内部线程
    gevent.joinall(threads) # gevent.joinall 阻塞当前流程 并执行所有给定的greenlet 执行完继续往下走

print('Synchronous')
synchronous()

print('Asynchronous')
asynchronous()

# coding:utf-8
import gevent.monkey
gevent.monkey.patch_socket()
import gevent
import urllib2
import json

def fetch(pid):
    response = urllib2.urlopen('http://www.baidu.com')
    result = response.read()
    print('Process %s: %s' % (pid, result))

def synchronous():
    for i in range(1, 10):
        fetch(i)

def asynchronous():
    threads = []
    for i in range(1,10):
        threads.append(gevent.spawn(fetch, i) for i in xrange(10))  # spawn将task函数封装到greenlet内部线程
    gevent.joinall(threads)

print('Synchronous')
synchronous()

print('Asynchronous')
asynchronous()

#coding:utf-8
import gevent
import gevent.monkey

gevent.monkey.patch_all()

# spawn_later函数可接收周期时间及运行函数。

INTERVAL = 10

def schedule(delay, func, *args, **kw_args):
    gevent.spawn_later(1, func, *args, **kw_args)
    gevent.spawn_later(delay, schedule, delay, func, *args, **kw_args)

def test1():
    print "func test1"

def test2():
    print "func test2"

def test3():
    print "test3"

schedule(1,test1)
schedule(2,test2)
schedule(3,test3)

while 1:
    gevent.sleep(1)