python3 进程和线程（二）

IO多路复用

select

基于select 实现socket服务端的伪并发

import socket
import select

sk1 = socket.socket()
sk1.bind(('127.0.0.1',8001,))
sk1.listen(5)

sk2 = socket.socket()
sk2.bind(('127.0.0.1',8002,))
sk2.listen(5)
inputs = [sk1,sk2,]
w_inputs = []
while True:
    # IO多路复用,同时监听多个socket对象
    #    - select,内部进行循环操作(1024)  主动查看
    #    - poll, 内部进行循环操作         主动查看
    #    - epoll,                        被动告知
    r,w,e = select.select(inputs,w_inputs,inputs,0.05)

    for obj in r:
        if obj in [sk1,sk2]:
            # 新连接来了...
            print('新连接来了:',obj)
            conn,addr = obj.accept()
            inputs.append(conn)
        else:
            # 有连接用户发送消息来了..
            print('有用户发送数据了:',obj)
            try:
                data = obj.recv(1024)
            except Exception as ex:
                data = ""
            if data:
                w_inputs.append(obj)
                # obj.sendall(data)
            else:
                obj.close()
                inputs.remove(obj)
                w_inputs.remove(obj)

    for obj in w:
        obj.sendall(b'ok')
        w_inputs.remove(obj)

#  Socket对象
sk1 = socket.socket()
sk1.bind(('127.0.0.1',8001,))
sk1.listen(5)
while True:
    # conn Socket对象,
    conn,addr = sk.accept()
    conn.recv()
    conn.sendall()

模拟socketserver

import socket
import select
import threading

def process_request(conn):
    while True:
        v = conn.recv(1024)
        conn.sendall(b'1111')

sk1 = socket.socket()
sk1.bind(('127.0.0.1',8001,))
sk1.listen(5)
inputs=[sk1,]
while True:
    # IO多路复用,同时监听多个socket对象
    #    - select,内部进行循环操作(1024)  主动查看
    #    - poll, 内部进行循环操作         主动查看
    #    - epoll,                        被动告知
    r,w,e = select.select(inputs,[],inputs,0.05)

    for obj in r:
        if obj in sk1:
            # conn客户端的socket
            conn,addr = obj.accept()
            t = threading.Thread(target=process_request,args=(conn,))
            t.start()

线程池回调函数

算是升级版，可以增加自定义函数，避免直接修改原程序

from concurrent.futures import ThreadPoolExecutor
import requests

def download(url):
    response = requests.get(url)
    return response # response包含了下载的所有内容

def run(url_list):
    pool = ThreadPoolExecutor(2)
    for item in url_list:
        url = item['url']
        call = item['call']
        future = pool.submit(download,url)
        future.add_done_callback(call)

以后增加新功能，只需要在下面代码中添加和修改，不用再修改new_thread

import new_thread
def f1(future):
    response = future.result()
    print(response.text)

def f2(future):
    response = future.result()
def f3(future):
    response = future.result()

url_list = [
    {'url':'http://www.oldboyedu.com','call': f1}, # a.txt
    {'url':'http://www.autohome.com.cn','call': f2}, # a.txt
    {'url':'http://www.baidu.com','call': f3}, # a.txt
]
new_thread.run(url_list)