code1
import time
import gevent
import requests
def foo():
print('Running in foo')

r=requests.get('http://30daydo.com')
print(r.status_code)
print('Explicit context switch to foo again')

def bar():
print('Explicit context to bar')

r=requests.get('http://www.qq.com') #
print(r.status_code)
print('Implicit context switch back to bar')

start=time.time()
gevent.joinall([
gevent.spawn(foo),
gevent.spawn(bar),
])
print('time used {}'.format(time.time()-start))
上面的异步代码不起作用,因为requests阻塞了,所以用的时间和顺序执行的时间一样.
 
或者用以下代码替代:
import time
import gevent
import requests
def foo():
print('Running in foo')
time.sleep(2) # 这样子不起作用
print('Explicit context switch to foo again')

def bar():
print('Explicit context to bar')
time.sleep(2)
print('Implicit context switch back to bar')

start=time.time()
gevent.joinall([
gevent.spawn(foo),
gevent.spawn(bar),
])
print('time used {}'.format(time.time()-start))
把访问网络部分使用sleep替代,那么最后的运行时间是2+2 =4秒,并不是2秒,那么要怎样才是2秒呢,需要改成以下的代码:
 
import time
import gevent
import requests
def foo():
print('Running in foo')

gevent.sleep(2) # 通过它各自yield向对方

print('Explicit context switch to foo again')

def bar():
print('Explicit context to bar')

gevent.sleep(2)

print('Implicit context switch back to bar')

start=time.time()
gevent.joinall([
gevent.spawn(foo),
gevent.spawn(bar),
])
print('time used {}'.format(time.time()-start))
使用gevent.sleep()
这个函数才可以达到目的. 查看全部

import time

import gevent

import requests

def foo():

    print('Running in foo')



    r=requests.get('http://30daydo.com')

    print(r.status_code)

    print('Explicit context switch to foo again')



def bar():

    print('Explicit context to bar')



    r=requests.get('http://www.qq.com') # 

    print(r.status_code)

    print('Implicit context switch back to bar')



start=time.time()

gevent.joinall([

    gevent.spawn(foo),

    gevent.spawn(bar),

])

print('time used {}'.format(time.time()-start))

import time

import gevent

import requests

def foo():

    print('Running in foo')

    time.sleep(2) # 这样子不起作用

    print('Explicit context switch to foo again')



def bar():

    print('Explicit context to bar')

    time.sleep(2)

    print('Implicit context switch back to bar')



start=time.time()

gevent.joinall([

    gevent.spawn(foo),

    gevent.spawn(bar),

])

print('time used {}'.format(time.time()-start))

import time

import gevent

import requests

def foo():

    print('Running in foo')



    gevent.sleep(2) # 通过它各自yield向对方



    print('Explicit context switch to foo again')



def bar():

    print('Explicit context to bar')



    gevent.sleep(2)



    print('Implicit context switch back to bar')



start=time.time()

gevent.joinall([

    gevent.spawn(foo),

    gevent.spawn(bar),

])

print('time used {}'.format(time.time()-start))