python - Why is there no content when calling readAll in a Qtcpsocket's readyRead callback? -

i building minimal socket server display window when receives message.

the server uses newconnection signal client connections , connect proper signals (connected, disconnected , readyread) each socket.

when running server program, , sending data proper address, each datum sent, qtcpsocket connected, readyread, disconnected. , within readyread callback, readall return nothing. (i suppose cause of disconnected signal).

still, client gets no "broken pipe error" , can continue send data.

how can happen ?

here's code :

class client(qobject):     def connects(self):         self.connect(self.socket, signal("connected()"), slot(self.connected()))         self.connect(self.socket, signal("disconnected()"), slot(self.disconnected()))         self.connect(self.socket, signal("readyread()"), slot(self.readyread()))         self.socket.error.connect(self.error)         print "client connected ip %s" % self.socket.peeraddress().tostring()      def error(self):         print "error somewhere"      def connected(self):         print "client connected event"      def disconnected(self):         self.readyread()         print "client disconnected"      def readyread(self):         print "reading"         msg = self.socket.readall()         print qstring(msg), len(msg)         n = notification(qstring(msg))         n.show()  class server(qobject):     def __init__(self, parent=none):         qobject.__init__(self)         self.clients = []      def setup_client_socket(self):         print "incoming"         client = client(self)         client.socket = self.server.nextpendingconnection()         #self.client.socket.nextblocksize = 0         client.connects()         self.clients.append(client)      def startserver(self):         self.server = qtcpserver()         self.server.listen(qhostaddress.localhost, 8888)         print self.server.islistening(), self.server.serveraddress().tostring(), self.server.serverport()         self.server.newconnection.connect(self.setup_client_socket) 

update : tested directly socket module python standard lib , works. general setup of machine , network not guilty parties there. qt issue.

the slot function expects string representing name of slot, , should preceded target of slot:

self.connect(self.socket, signal("connected()"), self, slot("connected()")) 

but without quotes, making immediate call function connect line is. didn't declare these functions slots using qtcore.slot/pyqtslot decorator, wouldn't called anyway when signals emitted, if use slot function.

for undecorated python functions, should use 1 of these syntaxes:

self.connect(self.socket, signal("connected()"), self.connected) 

or

self.socket.connected.connect(self.connected) 

notice lack of () @ end of last parameter.

additionally shouldn't call readyread in disconnected, if there data read before disconnection, readyread function called.