The attached hasn't failed on my box (Win XP Pro SP2, Python 2.3.5)
for about two hours, running it in 3 processes. Was using 2 processes
before; discovered it was much easier to provoke problems using 3; but
the # of ephemeral ports in use increases too, typically hovering
between 7-8 thousand after reaching steady state.
I'll let it run the rest of today, and start changing ZODB code if it
still looks good. I hope someone(s) else will then volunteer to port
the Windows changes to all the copies of Medusa code in the various
active Zope trunks and branches.
This suffers from what I still believe to be bugs in the Windows
socket implementation, but there is only one symptom I see with this,
and the code uses try/except to implement what appears to be a
import socket, errno
import time, random
w = socket.socket()
# Disable buffering -- pulling the trigger sends 1 byte,
# and we want that sent immediately, to wake up asyncore's
# select() ASAP.
w.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
count = 0
count += 1
# Bind to a local port; for efficiency, let the OS pick
# a free port for us.
# Unfortunately, stress tests showed that we may not
# be able to connect to that port ("Address already in
# use") despite that the OS picked it. This appears
# to be a race bug in the Windows socket implementation.
# So we loop until a connect() succeeds (almost always
# on the first try).
a = socket.socket()
connect_address = a.getsockname() # assigned (host, port) pair
except socket.error, detail:
if detail != errno.WSAEADDRINUSE:
# "Address already in use" is the only error
# I've seen on two WinXP Pro SP2 boxes, under
# Pythons 2.3.5 and 2.4.1.
# (10048, 'Address already in use')
# assert count <= 2 # never triggered in Tim's tests
if count >= 10: # I've never seen it go above 2
raise BindError("Cannot bind trigger!")
# Close `a` and try again. Note: I originally put a short
# sleep() here, but it didn't appear to help or hurt.
print detail, a.getsockname()
r, addr = a.accept() # r becomes asyncore's (self.)socket
return (r, w)
sofar = 
stuff = socktest29()
if len(sofar) == 50:
tup = sofar.pop(0)
r, w = tup
msg = str(random.randrange(1000000))
msg2 = r.recv(100)
assert msg == msg2, (msg, msg2, r.getsockname(), w.getsockname())
for tup in sofar:
for s in tup:
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