python - 'Port' object has no attribute 'socket' -

i'm using twisted python make simple ssh server on custom port. create port object port = reactor.listentcp(_port, sshfactory), _port variable holds integer of port. free port when shutting down server commands port.loseconnection() , port.connectionlost(reason=none). if attempt start server, stop it, , start again, titular error 'port' object has no attribute 'socket'

edit: full error message:

unhandled error in deferred: traceback (most recent call last):   file "c:\python27\lib\site-packages\twisted\internet\base.py", line 1175, in mainloop     self.rununtilcurrent()   file "c:\python27\lib\site-packages\twisted\internet\base.py", line 779, in rununtilcurrent     call.func(*call.args, **call.kw)   file "c:\python27\lib\site-packages\twisted\internet\defer.py", line 238, in callback     self._startruncallbacks(result)   file "c:\python27\lib\site-packages\twisted\internet\defer.py", line 307, in _startruncallbacks     self._runcallbacks() --- <exception caught here> ---   file "c:\python27\lib\site-packages\twisted\internet\defer.py", line 323, in _runcallbacks     self.result = callback(self.result, *args, **kw)   file "c:\python27\lib\site-packages\twisted\internet\task.py", line 736, in <lambda>     d.addcallback(lambda ignored: callable(*args, **kw))   file "c:\python27\lib\site-packages\twisted\internet\tcp.py", line 981, in connectionlost     self._closesocket()   file "c:\python27\lib\site-packages\twisted\internet\tcp.py", line 92, in _closesocket     skt = self.socket exceptions.attributeerror: 'port' object has no attribute 'socket' 

edit2: stoplistening code sample (python 2.7):

stoplistening sample.py

from twisted.cred import portal, checkers, credentials twisted.conch import error, avatar, recvline, interfaces conchinterfaces twisted.conch.ssh import factory, userauth, connection, keys, session, common twisted.conch.insults import insults twisted.application import service, internet twisted.internet import reactor, protocol zope.interface import implements import threading import os  class sshdemoprotocol(recvline.historicrecvline):     def __init__(self, user):         self.user = user      def connectionmade(self):         recvline.historicrecvline.connectionmade(self)         self.showprompt()      def showprompt(self):         self.terminal.write("$ ")  class sshdemorealm:     implements(portal.irealm)     def requestavatar(self, avatarid, mind, *interfaces):         if conchinterfaces.iconchuser in interfaces:             return interfaces[0], sshdemoavatar(avatarid), lambda: none         else:             raise exception("no supported interfaces found.")  def getrsakeys():     if not (os.path.exists('public.key') , os.path.exists('private.key')):         # generate rsa keypair         print("generating rsa keypair...")         crypto.publickey import rsa         key_length = 1024         rsakey = rsa.generate(key_length, common.entropy.get_bytes)         publickeystring = keys.makepublickeystring(rsakey)         privatekeystring = keys.makeprivatekeystring(rsakey)         # save keys next time         file('public.key', 'w+b').write(publickeystring)         file('private.key', 'w+b').write(privatekeystring)         print("done.")     else:         publickeystring = file('public.key').read()         privatekeystring = file('private.key').read()     return publickeystring, privatekeystring  def launchserver():     _port = 4564     password = 'password'     sshfactory = factory.sshfactory()     sshfactory.portal = portal.portal(sshdemorealm())     users = {'user': password}     sshfactory.portal.registerchecker(         checkers.inmemoryusernamepassworddatabasedontuse(**users))     pubkeystring, privkeystring = getrsakeys()     sshfactory.publickeys = {         'ssh-rsa': keys.getpublickeystring(data=pubkeystring)}     sshfactory.privatekeys = {         'ssh-rsa': keys.getprivatekeyobject(data=privkeystring)}     global port     port = reactor.listentcp(_port, sshfactory)     reactor.addsystemeventtrigger('before', 'shutdown', stopserver)     reactor.run(installsignalhandlers=false)  def startserver():     thread = threading.thread(target=launchserver)     thread.start()  def stopserver():     global port     port.stoplistening()     reactor.stop()     reactor.crash()  startserver() stopserver() startserver() 

traceback:

>>> exception in thread thread-2: traceback (most recent call last):   file "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner     self.run()   file "/usr/lib/python2.7/threading.py", line 505, in run     self.__target(*self.__args, **self.__kwargs)   file "/home/paul/desktop/down2home/stoplistening sample.py", line 62, in launchserver     port = reactor.listentcp(_port, sshfactory)   file "/usr/local/lib/python2.7/dist-packages/twisted-9.0.0-py2.7-linux-x86_64.egg/twisted/internet/posixbase.py", line 355, in listentcp     p.startlistening()   file "/usr/local/lib/python2.7/dist-packages/twisted-9.0.0-py2.7-linux-x86_64.egg/twisted/internet/tcp.py", line 855, in startlistening     raise cannotlistenerror, (self.interface, self.port, le) cannotlistenerror: couldn't listen on any:4564: [errno 98] address in use. 

listentcp returns ilisteningport; ilisteningport not have loseconnection or connectionlost methods. instead, has stoplistening. presence of methods you're calling unfortunate accident. should try using publicly advertised interfaces , see if works.

(also, should post completely runnable bit of code, know mean "stop , start again", complete traceback, rather snippet of error message.)

additionally, twisted apis may not invoked arbitrary threads. code provoke undefined , difficult predict behavior twisted:

def stopserver():     global port     port.stoplistening()     reactor.stop()     reactor.crash() 

for several reasons. first, startserver set application , started reactor in thread. means port.stoplistening() not allowed because it's twisted api being called in wrong thread. second, reactor.crash() testing helper, , in area, use discouraged better testing techniques have been developed since reactor.crash() invented.

you might away fix these problems:

from twisted.internet.threads import blockingcallfromthread  def startserver():     global thread     thread = threading.thread(target=launchserver)     thread.start()  def stopserver():     global port, thread     blockingcallfromthread(reactor, port.stoplistening)     reactor.callfromthread(reactor.stop)     thread.join()     thread = none 

of course, use of globals isn't ideal, i'm sticking them here keep code close original.

what is:

• call port.stoplistening in reactor thread using blockingcallfromthread. additionally, block until deferred returned stoplistening fires. means when line done, port no longer in use.
• call reactor.stop in reactor thread using reactor.callfromthread. since call intended stop reactor, don't think it's safe use blockingcallfromthread since once reactor stops inter-thread communication mechanism may no longer work. also, reactor.stop doesn't return deferred there's nothing useful block on anyway.
• wait reactor stop running joining thread in running (which block until launchserver returns, reactor.run() returns, once reactor stops).

however, may want consider not using threads @ in way. there's no particular reason so, @ least none can determine minimal example. if have other use of threads seems necessary you, might make fodder question. :)