python blocking sockets, send returns immediately
- by Mark
Hi,
I am writing a multithreaded socket application in Python using the socket module.
the server listens for connections and when it gets one it spawns a thread for that socket.
the server thread sends some data to the client. but the client is not yet ready to receive it. I thought this would have caused the server to wait until the client starts recv but instead returns immediately
the client then calls recv which is blocking and no data is ever received.
client socket constructor
self.__clientSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.__clientSocket.connect((server, port))
server socket constructor
self.servSock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.servSock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
#self.servSock.settimeout(None)
self.servSock.setblocking(1)
self.servSock.bind((self.addr,self.port))
self.servSock.listen(5)
listening accept thread
try:
(cs, address) = self.servSock.accept()
except socket.timeout:
return
threadName = '\r\nClient %s:%s\r\n' % (cs, address)
print threadName
clientSocketHandler = ClientSocket()
clientSocketHandler.setClientSocket(cs)
self.clients.newThread(self.clientFunc, {clientSocketHandler : "1"}, threadName).start()
server and clients send/rec methods from inside ClientSocket
receivedData = self.__clientSocket.recv(1024*1024)
self.__clientSocket.send(s)
any ideas why send() is returning straight away?
