Python编程中的并发与并行：深入解析阻塞、非阻塞、同步、异步及IO多路复用技术

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 import socket
 5 
 6 client = socket.socket()
 7 client.setblocking(False)  # 这里设置非阻塞  
 8 # 百度创建连接：阻塞
 9 try:
10     client.connect((‘www.baidu.com‘, 80))  # 执行了但报错
11 except BlockingIOError as e:
12     pass
13 
14 # 发送要东西了
15 client.sendall(b‘GET /s?wd=hello HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n‘)
16 
17 # 百度给我的回复
18 chunk_list = []
19 while True:
20     try:
21         # 阻塞
22         chunk = client.recv(8096)
23         if not chunk:
24             break
25         chunk_list.append(chunk)
26     except BlockingIOError:
27         pass
28 
29 print(b‘‘.join(chunk_list).decode(‘utf8‘))

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 import socket
 5 import select
 6 
 7 client1 = socket.socket()
 8 client1.setblocking(False)
 9 try:
10     client1.connect(("www.baidu.com", 80))
11 except BlockingIOError as e:
12     pass
13 
14 client2 = socket.socket()
15 client2.setblocking(False)
16 try:
17     client2.connect(("www.so.com", 80))
18 except BlockingIOError as e:
19     pass
20 socket_list = [client1, client2]
21 conn_list = [client1, client2]
22 while True:
23     rlist, wlist, elist = select.select(socket_list, conn_list, [], 0.005)
24     for sk in wlist:
25         if sk == client1:
26             sk.sendall(b‘GET /s?wd=hello HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n‘)
27         else:
28             sk.sendall(b‘GET /s?q=hello HTTP/1.0\r\nhost:www.so.com\r\n\r\n‘)
29         conn_list.remove(sk)
30 
31     for sk in rlist:
32         chunk_list = []
33         while True:
34             try:
35                 chunk = sk.recv(8096)
36                 if not chunk:
37                     break
38                 chunk_list.append(chunk)
39             except BlockingIOError as e:
40                 break
41         body = b"".join(chunk_list)
42         print("----->", body.decode(‘utf8‘))
43         # print("----->", body)
44         sk.close()
45         socket_list.remove(sk)
46     if not socket_list:
47         break
48 
49 """
50 回调：异步本质（通知）
51 def callback(arg):
52     print(arg)
53 func("www.baidu.com/s?wd=hello" callback)
54 print(123)
55 print(123)
56 print(123)
57 """

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 import socket
 5 import select
 6 
 7 
 8 class Req(object):
 9     def __init__(self, sk, func):
10         self.sock = sk
11         self.func = func
12 
13     def fileno(self):
14         return self.sock.fileno()
15 
16 
17 class Nb(object):
18 
19     def __init__(self):
20         self.conn_list = []
21         self.socket_list = []
22 
23     def add(self, url, func):
24         client = socket.socket()
25         client.setblocking(False)  
26         try:
27             client.connect((url, 80))
28         except BlockingIOError as e:
29             pass
30         obj = Req(client, func)
31         self.conn_list.append(obj)
32         self.socket_list.append(obj)
33 
34     def run(self):
35         while True:
36             rlist, wlist, elist = select.select(self.socket_list, self.conn_list, [], 0.005)
37             for sk in wlist:
38                 sk.sock.sendall(b‘GET /s?wd=hello HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n‘)
39                 self.conn_list.remove(sk)
40 
41             for sk in rlist:
42                 chunk_list = []
43                 while True:
44                     try:
45                         chunk = sk.sock.recv(8096)
46                         if not chunk:
47                             break
48                         chunk_list.append(chunk)
49                     except BlockingIOError as e:
50                         break
51                 body = b"".join(chunk_list)
52                 sk.func(body)
53                 sk.sock.close()
54                 self.socket_list.remove(sk)
55             if not self.socket_list:
56                 break
57 
58 
59 def baidu_response(body):
60     print(‘百度下载的结果‘, body)
61 
62 
63 def sogou_response(body):
64     print(‘搜狗下载的结果‘, body)
65 
66 
67 t1 = Nb()
68 t1.add(‘www.baidu.com‘, baidu_response)
69 t1.add(‘www.so.com‘, sogou_response)
70 t1.run()