At least on Ubuntu, this script will get into an infinite loop and chew up all your CPU. Sweet?!

hanger.py

#!/usr/bin/env python

import traceback
import subprocess
import eventlet
from eventlet.green import socket


def _spammer(address, xid):
    sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
    sock.connect(address)
    for i in xrange(10000):
        msg = '<13>message %d from %s' % (i, xid)
        try:
            sock.send(msg)
        except socket.error:
            traceback.print_exc()


def _restarter(sleep_time):
    eventlet.sleep(sleep_time)
    subprocess.call('sudo restart rsyslog', shell=True)


pool = eventlet.GreenPool(11)
for i in xrange(10):
    pool.spawn_n(_spammer, '/dev/log', i)
pool.spawn_n(_restarter, 0.01)

pool.waitall()

the_fix.diff

--- eventlet/greenio.py	2012-09-26 18:31:08.095164541 -0700
+++ eventlet/greenio.py.patched	2012-09-26 18:30:53.843498109 -0700
@@ -63,8 +63,8 @@
 else:
     # oddly, on linux/darwin, an unconnected socket is expected to block,
     # so we treat ENOTCONN the same as EWOULDBLOCK
-    SOCKET_BLOCKING = set((errno.EWOULDBLOCK, errno.ENOTCONN))
-    SOCKET_CLOSED = set((errno.ECONNRESET, errno.ESHUTDOWN, errno.EPIPE))
+    SOCKET_BLOCKING = set((errno.EWOULDBLOCK,))
+    SOCKET_CLOSED = set((errno.ECONNRESET, errno.ENOTCONN, errno.ESHUTDOWN, errno.EPIPE))
 
 
 def set_nonblocking(fd):

Hello. I'm sorry for late reply.

I tried to reproduce your test without syslog and sudo and failed. Perhaps, you could help with it, so we would include test and fix into eventlet source to avoid regressions.

https://gist.github.com/temoto/8259860