I'm setting up a listener for Hyperledger Sawtooth events with a pyzmq dealer socket and the provided asyncio functionality. Currently futures are returned but only sometimes finished, even though messages are sent to the Socket.
Weirdly this works for the connection message (only when sleeping before it as shown below) but not for event messages. I implemented this already with JavaScript and it works without problems. It seems that the issue does not lie with Sawtooth but rather in pyzmq's implementation of asyncio functionality or in my code.
class EventListener:
def __init__(self):
...
ctx = Context.instance()
self._socket = ctx.socket(zmq.DEALER)
self._socket.connect("tcp://127.0.0.1:4004")
async def subscribe(self):
...
await self._socket.send_multipart([connection_msg])
async def receive(self):
# Necessary wait otherwise the future is never finished
await asyncio.sleep(0.1)
resp = await self._socket.recv_multipart()
handle_response(resp)
async def listen(self):
while True:
# here sleep is not helping
# await asyncio.sleep(0.1)
# follwing await is never finished
resp = await self._socket.recv_multipart()
handle_response(resp)
...
listener = listener.EventListener()
await asyncio.gather(
listener.receive(), listener.subscribe())
await asyncio.create_task(listener.listen())
...
Debugging shows that the returned Future object is never changed from a pending to a finished state. So, is my code incorrect, do I need to await messages differently or is it possible that something is wrong with pyzmq's asyncio functionality? Also, why do I need to sleep in receive(), isn't that why we have asyncio?
