多线程是几乎所有现代编程语言（尤其是python）的核心概念，因为它的线程实现简单。
线程是程序内的子程序，可以独立于代码的其他部分执行。线程在同一上下文中执行，以共享程序的可运行资源（如内存）。
当在一个进程中，我们同时执行多个线程时，称为多线程。
为了在程序中实现线程，python提供了两个模块-
线程（对于python 2.x）或_thread（对于python 3.x）模块
穿线模块
线程模块将线程创建为函数，而线程模块提供面向对象的方法来创建线程。
_thread.start_new_thread(func, args[, kwargs])
上面启动了一个新线程并返回其标识符。第一个参数是函数func，线程将使用第二个参数执行该函数，该第二个参数包含具有参数位置列表的元组。可选的kwargs参数指定关键字参数的字典。当函数返回时，线程静默地存在。
在此，我们看到了客户端-服务器应用程序的基本示例。客户端从根本上打开套接字连接并将查询发送到服务器。服务器响应。
在不带任何参数的情况下运行，该程序从一个TCP套接字服务器启动，该服务器侦听端口8000上与127.0.0.1的连接。
client_thread1.py
import socket
import sys
def main():
soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "127.0.0.1"
port = 8000
try:
soc.connect((host, port))
except:
print("Connection Error")
sys.exit()
print("Please enter 'quit' to exit")
message = input(" -> ")
while message != 'quit':
soc.sendall(message.encode("utf8"))
if soc.recv(5120).decode("utf8") == "-":
pass # null operation
message = input(" -> ")
soc.send(b'--quit--')
if __name__ == "__main__":
main()服务器程序是
server_thread1.py
import socket
import sys
import traceback
from threading import Thread
def main():
start_server()
def start_server():
host = "127.0.0.1"
port = 8000 # arbitrary non-privileged port
soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
soc.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
print("Socket created")
try:
soc.bind((host, port))
except:
print("Bind failed. Error : " + str(sys.exc_info()))
sys.exit()
soc.listen(6) # queue up to 6 requests
print("Socket now listening")
# infinite loop- do not reset for every requests
while True:
connection, address = soc.accept()
ip, port = str(address[0]), str(address[1])
print("Connected with " + ip + ":" + port)
try:
Thread(target=client_thread, args=(connection, ip, port)).start()
except:
print("线程未启动。")
traceback.print_exc()
soc.close()
def clientThread(connection, ip, port, max_buffer_size = 5120):
is_active = True
while is_active:
client_input = receive_input(connection, max_buffer_size)
if "--QUIT--" in client_input:
print("Client is requesting to quit")
connection.close()
print("Connection " + ip + ":" + port + " closed")
is_active = False
else:
print("Processed result: {}".format(client_input))
connection.sendall("-".encode("utf8"))
def receive_input(connection, max_buffer_size):
client_input = connection.recv(max_buffer_size)
client_input_size = sys.getsizeof(client_input)
if client_input_size > max_buffer_size:
print("The input size is greater than expected {}".format(client_input_size))
decoded_input = client_input.decode("utf8").rstrip()
result = process_input(decoded_input)
return result
def process_input(input_str):
print("Processing the input received from client")
return "Hello " + str(input_str).upper()
if __name__ == "__main__":
main()在运行上述脚本时，请在终端中以以下方式运行server_thread1.py，
python server_thread1.py Socket created Socket now listening
我们将观看服务器窗口并了解流程。现在打开多个客户端终端，运行客户端线程
python client_thread1.py Enter 'quit' to exit -> Zack ->
在另一个终端中，也运行另一个客户端程序并监视服务器终端窗口，
python client_thread1.py Enter 'quit' to exit -> Python -> quit
另一个终端，运行客户端线程，
python client_thread1.py Enter 'quit' to exit -> world! -> Anothny ->
我们可以看到我们的服务器窗口将显示类似以下的输出，
Socket created Socket now listening Connected with 127.0.0.1:50275 Processing the input received from client Processed result: Hello ZACK Connected with 127.0.0.1:50282 Processing the input received from client Processed result: Hello PYTHON Processing the input received from client Client is requesting to quit Connection 127.0.0.1:50282 closed Connected with 127.0.0.1:50285 Processing the input received from client Processed result: Hello WORLD! Processing the input received from client Processed result: Hello ANOTHNY
因此，线程提供了一种最常见的技术来处理多个套接字连接和客户端。