April 23rd Summary

服务器：
import socket

sever=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
sever.bind(('192.168.12.81',8086))
while True:
    date,addr=sever.recvfrom(1024)
    print('来自客户端%s:%s的消息：%s'%(addr[0],addr[1],date.decode('utf-8')))
    msg=input('>>:').strip()
    sever.sendto(msg.encode('utf-8'),addr)
sever.close()

 客户端：
import socket
client=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
while True:
    msg=input('>>:').strip()
    client.sendto(msg.encode('utf-8'),('192.168.12.81',8086))
    date,addr=client.recvfrom(1024)
    print(date.decode(utf-8))
client.close() 

multi-channel technology: want the effect of concurrent execution of multiple processes on a single CPU
Time-sharing operating system: multiple online terminals + multi-channel technology 


CPU encounters IO operation switching is to improve efficiency , the 
process running time is too long, and the CPU switching process reduces the efficiency