from PyQt4 import QtGui, QtCore
import sys, socketserver
thd, thd2, thd3 = None, None, None

class T(QtCore.QThread):
    def __init__(self, f):
        super().__init__()
        self.f = f
    def run(self):
        print("running", self.f)
        self.f()

def thd_fin():
    print("Fin.")

def thd_fin3():
    print("Fin3.")

class TCPServer(socketserver.TCPServer):
    allow_reuse_address = True
class Handler(socketserver.BaseRequestHandler):
    def handle(self):
        global thd3
        thd3 = T(lambda: None)
        thd3.finished.connect(thd_fin3)
        thd3.start()

class Form(QtGui.QWidget):
    def __init__(self):
        super().__init__()
        global thd, thd2
        thd = T(lambda: None)
        thd.finished.connect(thd_fin)
        thd.start()

        self.server = TCPServer(("localhost", 50002), Handler)
        global thd2
        thd2 = T(self.server.serve_forever)
        thd2.start()

app = QtGui.QApplication(sys.argv)
form = Form()
form.show()
app.exec()