python basis of a model day41 IO IO multiplexing

server:

import select
import socket

sk = socket.socket()
sk.bind(('127.0.0.1',8000))
sk.setblocking(False)
sk.listen()

read_lst = [sk]
while True:   # [sk,conn]
    r_lst,w_lst,x_lst = select.select(read_lst,[],[])
    for i in r_lst:
        if i is sk:
            conn,addr = i.accept()
            read_lst.append(conn)
        else:
            ret = i.recv(1024)
            if ret == b'':
                i.close()
                read_lst.remove(i)
                continue
            print(ret)
            i.send(b'goodbye!')

client:

import time
import socket
import threading
def func():
    sk = socket.socket()
    sk.connect(('127.0.0.1',8000))
    sk.send(b'hello')
    time.sleep(3)
    print(sk.recv(1024))
    sk.close()

for i in range(20):
    threading.Thread(target=func).start()

 

IO multiplexing of three mechanisms:

select :windows linux

poll;linux

eploo:linux

Link: https: //www.cnblogs.com/Eva-J/articles/8324837.html

import selectors
from socket import *

def accept(sk,mask):
    conn,addr=sk.accept()
    sel.register(conn,selectors.EVENT_READ,read)

def read(conn,mask):
    try:
        data=conn.recv(1024)
        if not data:
            print('closing',conn)
            sel.unregister(conn)
            conn.close()
            return
        conn.send(data.upper()+b'_SB')
    exceptException:
         Print ( ' the closing ' , Conn) 
        sel.unregister (Conn) 
        conn.Close () 

SK = Socket () 
sk.setsockopt (SOL_SOCKET, the SO_REUSEADDR, . 1 ) 
sk.bind (( ' 127.0.0.1 ' , 8088 )) 
sk.listen ( 5 ) 
sk.setblocking (False) # set socket interface for non-blocking 
SEL = selectors.DefaultSelector ()    # to select a suitable mechanism for my IO multiplexed 
sel.register (sk, selectors.EVENT_READ, the Accept)
 # equivalent net select reading list append a sk object, and a callback function to bind the Accept 
# it means if someone requests a connection sk, calls the method accrpt

the while True: 
    Events = sel.select () # detect all sk, conn, wait data for the completion stage 
    for sel_obj, mask in Events:   # [Conn] 
        the callback = sel_obj.data # the callback = Read 
        the callback (sel_obj.fileobj, mask) # the Read (conn, 1)