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pythonpython-3.xpython-asyncioautobahnwamp-protocol

Running several ApplicationSessions non-blockingly using autbahn.asyncio.wamp


I'm trying to run two autobahn.asyncio.wamp.ApplicationSessions in python at the same time. Previously, I did this using a modification of the autobahn library as suggested in this post's answer. I now require a bit more professional solution.

After googling about for a while, this post appeared quite promising, but uses the twisted library, instead of asyncio. I wasn't able to identify a similar solution for the asyncio branch of the autobahn library, since it doesn't appear to be using Reactors.

The main problem I have, is that ApplicationRunner.run() is blocking (which is why I previously outsourced it to a thread), so I can't just run a second ApplicationRunner after it.

I do need to access 2 websocket channels at the same time, which I cannot appear to do with a single ApplicationSession.

My Code so far:

from autobahn.asyncio.wamp import ApplicationSession
from autobahn.asyncio.wamp import ApplicationRunner
from asyncio import coroutine
import time


channel1 = 'BTC_LTC'
channel2 = 'BTC_XMR'

class LTCComponent(ApplicationSession):

    def onConnect(self):
        self.join(self.config.realm)

    @coroutine
    def onJoin(self, details):
        def onTicker(*args, **kwargs):
            print('LTCComponent', args, kwargs)

        try:
            yield from self.subscribe(onTicker, channel1)
        except Exception as e:
            print("Could not subscribe to topic:", e)

class XMRComponent(ApplicationSession):

    def onConnect(self):
        self.join(self.config.realm)

    @coroutine
    def onJoin(self, details):
        def onTicker(*args, **kwargs):
            print('XMRComponent', args, kwargs)

        try:
            yield from self.subscribe(onTicker, channel2)
        except Exception as e:
            print("Could not subscribe to topic:", e)

def main():
    runner = ApplicationRunner("wss://api.poloniex.com:443", "realm1", extra={})
    runner.run(LTCComponent)
    runner.run(XMRComponent) # <- is not being called


if __name__ == "__main__":

    try:
        main()
    except KeyboardInterrupt:
        quit()

    except Exception as e:
        print(time.time(), e)

My knowledge of the autobahn library is limited, and I'm afraid the documentation isn't improving my situation much. Am I overlooking something here? A function, a parameter, which would enable me to either compound my components or run them both at once?

Perhaps a similar solution as provided here, which implements an alternative ApplicationRunner ?


Related Topics

Running two ApplicationSessions in twisted

Running Autobahn ApplicationRunner in Thread

Autobahn.wamp.ApplicationSession Source

Autobahn.wamp.Applicationrunner Source


As Requested, the Traceback from @stovfl's answer using multithreading code:

Exception in thread Thread-2:
Traceback (most recent call last):
  File "/home/nils/anaconda3/lib/python3.5/threading.py", line     914, in _bootstrap_inner
    self.run()
  File "/home/nils/git/tools/gemini_wss/t2.py", line 27, in run
    self.appRunner.run(self.__ApplicationSession)
  File "/home/nils/anaconda3/lib/python3.5/site-packages/autobahn-    0.14.1-py3.5.egg/autobahn/asyncio/wamp.py", line 143,     in run
    transport_factory = WampWebSocketClientFactory(create,         url=self.url,                 serializers=self.serializers)
  File "/home/nils/anaconda3/lib/python3.5/site-packages/autobahn-    0.14.1-py3.5.egg/autobahn/asyncio/websocket.py", line     319, in __init__
    WebSocketClientFactory.__init__(self, *args, **kwargs)
  File "/home/nils/anaconda3/lib/python3.5/site-packages/autobahn-    0.14.1-py3.5.egg/autobahn/asyncio/websocket.py", line     268, in __init__
    self.loop = loop or asyncio.get_event_loop()
  File "/home/nils/anaconda3/lib/python3.5/asyncio/events.py",     line 626, in get_event_loop
    return get_event_loop_policy().get_event_loop()
  File "/home/nils/anaconda3/lib/python3.5/asyncio/events.py",     line 572, in get_event_loop
    % threading.current_thread().name)
RuntimeError: There is no current event loop in thread 'Thread-2'.
Exception in thread Thread-1:
**Same as in Thread-2**
...
RuntimeError: There is no current event loop in thread 'Thread-1'.

Solution

  • Following the approach you linked for twisted I managed to get same behaviour with asyncio setting start_loop=False

    import asyncio
    from autobahn.asyncio.wamp import ApplicationSession, ApplicationRunner
    
    runner1 = ApplicationRunner(url, realm, extra={'cli_id': 1})
    coro1 = runner1.run(MyApplicationSession, start_loop=False)
    
    runner2 = ApplicationRunner(url, realm, extra={'cli_id': 2})
    coro2 = runner2.run(MyApplicationSession, start_loop=False)
    
    asyncio.get_event_loop().run_until_complete(coro1)
    asyncio.get_event_loop().run_until_complete(coro2)
    asyncio.get_event_loop().run_forever()
    
    class MyApplicationSession(ApplicationSession):
    
        def __init__(self, cfg):
            super().__init__(cfg)
            self.cli_id = cfg.extra['cli_id']
    
       def onJoin(self, details):
            print("session attached", self.cli_id)