pyzmq: ioloop in separate thread

gistfile1.py

import zmq, zmq.eventloop.zmqstream,zmq.eventloop.ioloop
import threading

import logging
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger()

zmq.eventloop.ioloop.install()

# run ioloop in separate thread
def threaded_loop():
    while True:
        logger.debug("starting IOLoop")
        zmq.eventloop.ioloop.IOLoop.instance().start()
t = threading.Thread(target=threaded_loop)
t.daemon = True
t.start()

context = zmq.Context()

# like echo - but better
def exclaim(stream, msg):
    stream.send("{}!".format(msg[0].upper()))

address = "tcp://127.0.0.1:20120"
rep = context.socket(zmq.REP)
rep.bind(address)
rep_stream = zmq.eventloop.zmqstream.ZMQStream(rep)
rep_stream.on_recv_stream(exclaim)

# the thread ioloop is wrapped in a `while True` so it
# will immediately start up again - we stop it so it picks up (?) the
# newly added `REP` stream
zmq.eventloop.ioloop.IOLoop.instance().stop()

req = context.socket(zmq.REQ)
logger.debug("connecting")
req.connect(address)
logger.debug("sending")
req.send("steveholt")
logger.debug("receiving")
assert(req.recv() == "STEVEHOLT!")
logger.debug("done")

Output from the above:

DEBUG:root:starting IOLoop
DEBUG:root:connecting
DEBUG:root:starting IOLoop
DEBUG:root:sending
DEBUG:root:receiving
DEBUG:root:done