python socket.error: [Errno 9] Bad file descriptor

Question

I wanted to make a server and a client with Python. It was supposed to make multiple connections, one, where the server is sending something to the client, and one where the client is sending something to the server.

The first connection worked fine, but the second one crashed with the message:

socket.error: [Errno 9] Bad file descriptor

Here is the Server:

import socket
import errno
import pickle
def Main():
 host = '188.174.233.99'
 port = 66666
 all_text = ['text1', 'text2', 'text3']
 all_description = ['Test \n Description1\n', 'Test \n Description1\n', 'Test \n Description1\n']
 all_images = ['unlock.png', 'unlock.png', 'unlock.png']
 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP)
 s.bind((host, port))
 s.listen(1)
 while True:
 c, addr = s.accept()
 c.setblocking(0)
 print "Connection from: " + str(addr)
 command = c.recv(1024)
 if command == 'GIVEALL':
 textstring = pickle.dumps([all_text, all_images, all_description])#verwandelt Liste in String
 c.send(textstring)
 else:
 try:
 new_event = pickle.loads(command)
 print new_event
 caption = new_event[0]
 image = new_event[1]
 describtion = new_event[2]
 city = new_event[3]
 except:
 pass
 try:
 c.close()
 s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
 except socket.error as e:
 if e.errno != errno.ECONNRESET:
 raise
 pass
if __name__ == '__main__':
 Main()

And here is the Client:

import socket import pickle

from kivy.properties import StringProperty
from kivy.properties import NumericProperty
from kivy.properties import ListProperty
class Netclient(object):
 def __init__(self):
 self.s = socket.socket()
 self.texte = []
 self.current = 'All'
 self.ip = '188.174.233.99'
 self.port = 66666
 def giveWid(self):
 print 'give Widgets executed'
 if self.current == 'All':
 self.texte, self.images, self.description = self.sentHOT(self.ip, self.port)
 return self.texte, self.images, self.description
 def sentHOT(self, host, port):
 self.s.connect((host, port))
 self.s.send('GIVEALL')#sends command
 recived_string = self.s.recv(1023)
 more_text = pickle.loads(recived_string)#verwandelt string in liste
 self.s.close()
 print 'closed'
 return more_text[0], more_text[1], more_text[2]
 def add_event(self, caption, image, description, city='Pawonkow'):
 new_event = [caption, image, description, city]
 new_compact_event = pickle.dumps(new_event)
 self.s.connect((self.ip, self.port))
 self.s.send(new_compact_event)
 self.s.close()
 n = Netclient()
 t, i, d = n.giveWid()
 print t
 n.add_event('new', 'new.png', 'ew event', 'Hanau')

• dsgdfg: Server can't close connection ! Put every connection to in a thread, close method only acceptable on server side...
• dsgdfg: You can use close method if want reject a client connection.
• Evan Carroll: Possible duplicate of Getting Errno 9: Bad file descriptor in python socket

Answer 1

The reason is that you are trying to reconnect a closed socket. You have to either create a new socket or reuse the old one as long as it's connected.

In method def sentHOT(...): comment the line self.s.close() and in method def add_event(...) comment the line self.s.connect((self.ip, self.port)) then should work. Further, please take a look at this tutorial, it helps you with socket programming.

• jobou: Good catch. I did not understand the problem first. I thought he means that he was starting 2 clients at the same time. I have deleted my post as it was not the right answer.
• Gilgamesch von Uruk: what would it look like, if I had a new socket for both functions?
• mitghi: @GilgameschvonUruk Can you explain a bit more ? Do you mean creating a new socket each time the function is called ?
• Gilgamesch von Uruk: yes, I actually did it, and it worked ,kind of, shoud I post the code?
• jobou: Look here : stackoverflow.com/a/10810769/1951430 you have base native python classes to do this. Note the comment at the end with the Forking or Threading mixin, it is important because natively the TCPServer behaves synchronously (it waits for the end of one request to process the next)