标签：threading encode 声明 break arm play ica serve bind
协程，又叫微线程，纤程。英文名Coroutine。协程本质上就是一个线程
优点1：协程极高的执行效率。因为子程序切换不是线程切换，而是由程序自身控制，因此，没有线程切换的开销，和多线程比，线程数量越多，协程的性能优势就越来越明显。(简单来说没有切换的消耗)
优点2：不需要多线程的锁机制，因为只有一个线程，也不存在同时写变量冲突，在协程中控制共享资源不加锁，只需要判断状态就好，所以执行效率比多线程高很多。(没有锁的概念)
因为协程是一个线程执行，那怎么利用多核CPU呢？最简单的方法是多进程+协程，既充分利用多核，又充分发挥协程的高效率，可获得极高的性能。
#_*_ coding:utf-8 _*_
# Author:Simon
# Datetime:2019/9/2 21:07
# Software:PyCharm
import time
import queue
def consumer(name):
print("--->ready to eat baozi...")
while True:
new_baozi = yield
print("[%s] is eating baozi %s" % (name,new_baozi))
#time.sleep(1)
def producer():
r = con.__next__()
r = con2.__next__()
n = 0
while 1:
time.sleep(1)
print("\033[32;1m[producer]\033[0m is making baozi %s and %s" %(n,n+1) )
con.send(n)
con2.send(n+1)
n +=2
if __name__ == ‘__main__‘:
con = consumer("c1")
con2 = consumer("c2")
p = producer()
#_*_ coding:utf-8 _*_
# Author:Simon
# Datetime:2019/9/2 21:29
# Software:PyCharm
from greenlet import greenlet
def test1():
print(12)
gr2.switch()
print(34)
gr2.switch()
def test2():
print(56)
gr1.switch()
print(78)
gr1 = greenlet(test1)
gr2 = greenlet(test2)
gr1.switch()
本质就是封装了greenlet模块，它能检测I/O并且遇到I/O自动切换到另外一个任务执行；可以帮我们提升效率
#_*_ coding:utf-8 _*_
# Author:Simon
# Datetime:2019/9/2 21:39
# Software:PyCharm
import gevent
import requests,time
start=time.time()
def f(url):
print(‘GET: %s‘ % url)
resp =requests.get(url)
data = resp.text
print(‘%d bytes received from %s.‘ % (len(data), url))
gevent.joinall([
gevent.spawn(f, ‘https://www.jd.org/‘),
gevent.spawn(f, ‘https://www.xiaohua.com/‘),
gevent.spawn(f, ‘https://www.baidu.com/‘),
gevent.spawn(f, ‘https://www.taobao.com/‘),
])
# f(‘https://www.jd.org/‘)
# f(‘https://www.xiaohua.com/‘)
# f(‘https://baidu.com/‘)
# f(‘https://www.taobao.com/‘)
#
# print("cost time:",time.time()-start)
gevent异步提交任务
from gevent import monkey;monkey.patch_all()
import gevent
import time
def eat(name):
print(‘%s eat 1‘ % name)
time.sleep(3)
print(‘%s eat 2‘ % name)
def play(name):
print(‘%s play 1‘ % name)
time.sleep(4)
print(‘%s play 2‘ % name)
g1=gevent.spawn(eat,‘simon‘)
g2=gevent.spawn(play,‘zhuzhu‘)
# time.sleep(5)
# g1.join()
# g2.join()
gevent.joinall([g1,g2]) #相当于上边两行代码
打印：
simon eat 1
zhuzhu play 1
simon eat 2
zhuzhu play 2
基于gevent模块实现并发的套接字通信
单线程、多任务的I/O操作。
#基于gevent实现
from gevent import monkey,spawn;monkey.patch_all()
from socket import *
def communicate(conn):
while True:
try:
data=conn.recv(1024)
if not data:break
conn.send(data.upper())
except ConnectionResetError:
break
conn.close()
def server(ip,port):
server = socket(AF_INET, SOCK_STREAM)
server.bind((ip,port))
server.listen(5)
while True:
conn, addr = server.accept()
spawn(communicate,conn) #造一个协程对象，提交完这个对象它不会执行
server.close()
if __name__ == ‘__main__‘:
g=spawn(server,‘127.0.0.1‘,8090)
g.join()
##客户端
from socket import *
from threading import Thread,currentThread
def client():
client=socket(AF_INET,SOCK_STREAM)
client.connect((‘127.0.0.1‘,8090))
while True:
client.send((‘%s hello‘ %currentThread().getName()).encode(‘utf-8‘))
data=client.recv(1024)
print(data.decode(‘utf-8‘))
client.close()
if __name__ == ‘__main__‘:
for i in range(500):
t=Thread(target=client)
t.start()
标签：threading encode 声明 break arm play ica serve bind
原文地址：https://www.cnblogs.com/hackerer/p/11449463.html
