twisted: multiple logins with a uniq Perspective Broker TCP connection - twisted

Question

I'm working on a code that use Twisted this way: a client establishes a permanent Perspective Broker TCP connection (ie, the connection is kept open during the whole process live, which can be days, months or years), and performs logins using this broken for different Avatars when needed.
My problem is that the Avatar logout clean up function is recorded by the broker, to be called and removed when the broker TCP connection is lost.
My problem is that the connection is never lost, and the broker.disconnects list increases more and more.
Even worse, the avatar logout function in defined by the code I'm working on has a reference on the Avatar (by closure), and the avatars can be big, causing a problematic memory leak to the whole process.
Here is an example adpated frome the doc:
The server:
#!/usr/bin/env python
# Inspired from pb6server.py here:
# https://twistedmatrix.com/documents/current/core/howto/pb-cred.html#two-clients
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
from zope.interface import implementer
from twisted.spread import pb
from twisted.cred import checkers, portal
from twisted.internet import reactor
PROTOCOL = None
# I didn't find another way to get a reference to the broker: suggestion
# welcome!
class MyFactory(pb.PBServerFactory):
def buildProtocol(self, addr):
global PROTOCOL
PROTOCOL = super().buildProtocol(addr)
return PROTOCOL
class MyPerspective(pb.Avatar):
def __init__(self, name):
self.name = name
def perspective_foo(self, arg):
assert PROTOCOL is not None
print(f"Leaked avatars: {len(PROTOCOL.disconnects)}")
#implementer(portal.IRealm)
class MyRealm:
def requestAvatar(self, avatarId, mind, *interfaces):
if pb.IPerspective not in interfaces:
raise NotImplementedError
return pb.IPerspective, MyPerspective(avatarId), lambda: None
p = portal.Portal(MyRealm())
c = checkers.InMemoryUsernamePasswordDatabaseDontUse(
user0=b"pass0", user1=b"pass1", user2=b"pass2", user3=b"pass3", user4=b"pass4"
)
p.registerChecker(c)
factory = MyFactory(p)
reactor.listenTCP(8800, factory)
reactor.run()
And the client:
#!/usr/bin/env python
# Inspired from pb6client.py here:
# https://twistedmatrix.com/documents/current/core/howto/pb-cred.html#two-clients
from twisted.spread import pb
from twisted.internet import reactor
from twisted.cred import credentials
USERS_COUNT = 5
def main():
factory = pb.PBClientFactory()
reactor.connectTCP("localhost", 8800, factory)
for k in range(10):
i = k % USERS_COUNT
def1 = factory.login(
credentials.UsernamePassword(f"user{i}".encode(), f"pass{i}".encode())
)
def1.addCallback(connected)
reactor.run()
def connected(perspective):
print("got perspective1 ref:", perspective)
print("asking it to foo(13)")
perspective.callRemote("foo", 13)
main()
How may I notify the broker that the avatar should be cleaned, whitout closing the broker TCP connection?
Thanks!