[Twisted-Python] reactor.addSystemEventTrigger("before", "shutdown", self.logout)

[Manlio Perillo]

Hi.

I would like to have a function be called at the very end of the reactor
lifetime.

I have tried with the statement in the subject, where self.logout sends
a packet via UDP (self is an instance of a class derived from
DatagramProtocol).

But this seems to be not allowed.
I obtain:

Traceback (most recent call last):
File "...\twisted\python\log.py",  line 53, in callWithLogger

  	[...]

--- <exception caught here> ---
File "...\twisted\internet\selectreactor.py", line 139, in doReadOrWrite
  why = getattr(selectable, method)()
File "...\twisted\internet\udp.py", line 114, in doRead
  data, addr = self.socket.recvfrom(self.maxPacketSize)
  exceptions.AttributeError: 'Port' object has no attribute 'socket'


Traceback (most recent call last):
File "justmyscript.py", line 79, in ?
  reactor.run()

	[...]

--- <exception caught here> ---
File "...\twisted\python\log.py", line 53, in callWithLogger
  return callWithContext({"system": lp}, func, *args, **kw)
File "...\twisted\python\log.py", line 38, in callWithContext
  return context.call({ILogContext: newCtx}, func, *args, **kw)
File "...\twisted\python\context.py", line 59, in callWithContext
  return self.currentContext().callWithContext(ctx, func, *args, **kw)
File "...\twisted\python\context.py", line 37, in callWithContext
  return func(*args,**kw)
File "...\twisted\internet\selectreactor.py", line 149, in doReadOrWrite
  self._disconnectSelectable(selectable, why, method=="doRead")
File "...\twisted\internet\posixbase.py", line 256, in _disconnectSelectable
  selectable.connectionLost(failure.Failure(why))
File "...\twisted\internet\udp.py", line 207, in connectionLost
  self.protocol.doStop()
File "...\twisted\internet\protocol.py", line 490, in doStop
  assert self.numPorts > 0
  exceptions.AssertionError:



This means, in short, that in a shutdown event I can't use the reactor?
I think that this should be documented.




Thanks and regards  Manlio Perillo