Python -- 协程(2)

以下使用gevent模块实现协程，人工控制产生IO阻塞，而不是等某个线程结束后  其他线程竞争式抢资源。注意：gevent模块要从网上找

import gevent,time
def foo():
    print('Running in foo',time.ctime())
    gevent.sleep(2)    #使用gevent来模拟IO阻塞，从而使切换到其他线程
    print('Explicit context switch to foo again',time.ctime())

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

gevent.joinall([
    gevent.spawn(foo),
    gevent.spawn(bar)
])

输出：

Running in foo Tue Dec 21 21:49:29 2021
Explicit context to bar Tue Dec 21 21:49:29 2021
Explicit context switch to foo again Tue Dec 21 21:49:31 2021
Implicit context switch back to bar Tue Dec 21 21:49:31 2021