CODEWITHSUNDEEP
pythonsocketsinterrupt
BlockCoder
BlockCoder

Reputation: 135

How to interrupt socket.recv() in python?

I'm developing a small server system and I need to turn the server off whenever I type "exit()" into the console (the input is handled from another thread) I was wondering if there is a way to terminate the main thread while the socket is awaiting data. I've already tried using _thread.interrupt_main() with a keyboardInterrupt exception in a try block but it didn't work. I also tried os._exit() which worked but it doesn't clean up so I decided not to use it. My code:

import socket
import _thread
import os

clear = lambda: os.system("cls")

try:
    Server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    Server.bind(("localhost",port))
    Server.listen(2)
    clear()
    print("--------------------------------------")
    print("Server running on port %s" % str(port))
    print("--------------------------------------")
except Exception:
    print("error while starting server")
    input()
    exit()

def control():
    while True:
        command = input()
        if command == "exit()":
            #interrupt code here

_thread.start_new_thread(control,())

while True:
    con,ip = Server.accept()
    print(str(ip) + " Connected")

    try:
        cmd = str(con.recv(1024).decode())  #<-- interrupt this line
    except Exception:
        print("Error")

Upvotes: 3

Views: 7753

Answers (2)

debuti
debuti

Reputation: 683

sock.shutdown(socket.SHUT_RDWR) is quite handy if you have the socket in the main thread and the thread is blocked in recv/recvfrom/etc. The recv call will end up in an exception and you can use that to finish your thread if you need to.

Upvotes: 4

mr_pool_404
mr_pool_404

Reputation: 498

Below code does what you want but on a basic level for closing connection of single client. You should restructure your code for handling multiple clients if you wish so. Best idea would be to start new thread for each connection of same socket connection so that you could handle them seperately.

import socket
import _thread
import os

clear = lambda: os.system("cls")
port = 1026
try:
    Server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    Server.bind(("127.0.0.1",1026))
    Server.listen(2)
    print("--------------------------------------")
    print("Server running on port %s" % str(port))
    print("--------------------------------------")
except Exception:
    print("error while starting server")
    input()
    exit()

def control(sock):
    while True:
        command = input()
        if command == "exit()":
            sock.close()
            os._exit(0)
            #interrupt code here


while True:
    con,ip = Server.accept()
    _thread.start_new_thread(control,(con,))
    print(str(ip) + " Connected")

    try:
        cmd = str(con.recv(1024).decode())  #<-- interrupt this line
    except Exception:
        print("Error")

Upvotes: 1

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