协程与线程套接字通讯
基于多线程实现套接字服务端支持并发,服务端
from socket import *
from threading import Thread
def comunicate(conn):
while True: # 通信循环
try:
data = conn.recv(1024)
if len(data) == 0: break
conn.send(data.upper())
except ConnectionResetError:
break
conn.close()
def server(ip, port, backlog=5):
server = socket(AF_INET, SOCK_STREAM)
server.bind((ip, port))
server.listen(backlog)
while True: # 链接循环
conn, client_addr = server.accept()
print(client_addr) # 通信
t=Thread(target=comunicate,args=(conn,))
t.start()
if __name__ == '__main__':
s=Thread(target=server,args=('127.0.0.1',8081))
s.start()
单线程下实现并发的套接字通信,服务端
from gevent import monkey;monkey.patch_all() #******
from socket import *
from gevent import spawn
def comunicate(conn):
while True: # 通信循环
try:
data = conn.recv(1024)
if len(data) == 0: break
conn.send(data.upper())
except ConnectionResetError:break
conn.close()
def server(ip, port, backlog=5):
server = socket(AF_INET, SOCK_STREAM)
server.bind((ip, port))
server.listen(backlog)
while True: # 链接循环
conn, client_addr = server.accept()
print(client_addr)
spawn(comunicate,conn) # 通信
if __name__ == '__main__':
g1=spawn(server,'127.0.0.1',8080)
g1.join()
进程池线程池,同步/异步调用
from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor
import time,random,os
def task(name,n):
print('%s%s is running' %(name,os.getpid()))
time.sleep(random.randint(1,3))
return n**2
if __name__ == '__main__':
# print(os.cpu_count())
p=ProcessPoolExecutor(4)
#提交任务的两种方式:
# 同步调用:提交完一个任务之后,就在原地等待,等待任务完完整整地运行完毕拿到结果后,再执行下一行代码,会导致任务是串行执行的
# 异步调用:提交完一个任务之后,不在原地等待,结果???,而是直接执行下一行代码,会导致任务是并发执行的
l=[]
for i in range(10): # 同步提交
# res=p.submit(task,'进程pid: ',i).result()
# print(res) # 异步提交
future=p.submit(task,'进程pid: ',i)
l.append(future)
p.shutdown(wait=True) #关闭进程池的入口,并且在原地等待进程池内所有任务运行完毕
for future in l:
print(future.result())
print('主')
补充:1
p=ProcessPoolExecutor(9)
start=time.time()
for url in urls:
future=p.submit(get,url)
# 异步调用:提交完一个任务之后,不在原地等待,而是直接执行下一行代码,会导致任务是并发执行的,,结果futrue对象会在任务运行完毕后自动传给回调函数
future.add_done_callback(parse) #parse会在任务运行完毕后自动触发,然后接收一个参数future对象
p.shutdown(wait=True)
补充:2
p=ThreadPoolExecutor(4)
for url in urls:
future=p.submit(get,url)
future.add_done_callback(parse)
p.shutdown(wait=True)
协程
1. 目标:
在线程下实现并发
并发(多个任务看起来是同时执行就是并发):切换+保存状态
2. 协程:
协程是单线程实现并发
注意:协程是程序员意淫出来的东西,操作系统里只有进程和线程的概念(操作系统调度的是线程)
在单线程下实现多个任务间遇到IO就切换就可以降低单线程的IO时间,从而最大限度地提升单线程的效率
gevent模块实现单线程并发通讯,服务端
from gevent import monkey;monkey.patch_all()
from gevent import spawn,joinall #pip3 install gevent
import time
def play(name):
print('%s play 1' %name)
time.sleep(5)
print('%s play 2' %name)
def eat(name):
print('%s eat 1' %name)
time.sleep(3)
print('%s eat 2' %name)
start=time.time()
g1=spawn(play,'刘清正')
g2=spawn(eat,'刘清正')
# g1.join()
# g2.join()
joinall([g1,g2])
print('主',time.time()-start)