Handlers Cannot Terminate Connection

[alexmbird]

I'm trying to write some code that'll handle a fixed number of events then exit. The natural way to do this seems to be calling Pusher.disconnect() from a handler once it's seen enough events.

But since the callbacks are fired from within Pusher's connection thread and disconnect() ends in a Thread.join(), this results in a RuntimeError.

Example code:

import time
import pusherclient

class MyClient(object):
    
    STOP_AT_N = 5
    
    def __init__(self):
        super(MyClient,self).__init__()
        self.n_events = 0
    
    def connect(self):
        "Connect to a random Pusher channel & consume events"
        self.pusher = pusherclient.Pusher('de504dc5763aeef9ff52')
        def event_handler(e):
            self.n_events += 1
            print("event %d" % (self.n_events,))
            if self.n_events >= self.STOP_AT_N:
                self.pusher.disconnect()
        def connect_handler(data):
            channel = self.pusher.subscribe('live_orders')
            channel.bind('order_created', event_handler)
        self.pusher.connection.bind('pusher:connection_established', connect_handler)
        self.pusher.connect()


if __name__ == '__main__':
    mc = MyClient()
    mc.connect()
    while True:
        time.sleep(1)

What happens for me:

$ python3 experiments/pusher_handler_disconnect.py
event 1
event 2
event 3
event 4
event 5
error from callback <bound method Connection._on_message of <Connection(Thread-1, started daemon 123145422946304)>>: cannot join current thread

[joders]

had the same problem. turns out you need to call disconnect from outside the handler to avoid the error. that is in many cases very inconvenient. I ended up creating a separate thread that's checking the result which I stored in something more global periodically and calling disconnect accordingly