CODEWITHSUNDEEP
pythonmultithreadingpython-multithreadingpaho
Bindu Manjunath
Bindu Manjunath

Reputation: 49

RuntimeError: cannot set daemon status of active thread

I am trying to run some test in parallel upon on_message callback. When my on_message callback gets called, based on some message, I create a thread to run some test and set it as daemon thread. When I run, I get this run-time error.

"cannot set daemon status of active thread".

#this is the callback attached to paho.mqtt.client client.on_message = self.on_message
def on_message(self, client, userdata, msg):
        if  msg.topic.startswith("hello/"):
            #set some vlaues              
        elif msg.topic.startswith("data/"):
            #set some vlaues                                 
        elif msg.topic.startswith("test/"):
            value =  msg.payload.decode("utf-8")  
            lst = value.split('-')
            test = Test()
            test._value = lstr[0]
            t = Thread(target = test.callmethod,args=(lst[1]))  
            t.start()
            t.setDaemon(True)

 Exception in thread Thread-2:
 Traceback (most recent call last):
   File "/usr/local/lib/python3.6/threading.py", line 916, in _bootstrap_inner
     self.run()
   File "/usr/local/lib/python3.6/threading.py", line 864, in run
     self._target(*self._args, **self._kwargs)
 TypeError: mymethod() takes 2 positional arguments but 10 were given

 Exception in thread Thread-1:
 Traceback (most recent call last):
   File "/usr/local/lib/python3.6/threading.py", line 916, in _bootstrap_inner
     self.run()
   File "/usr/local/lib/python3.6/threading.py", line 864, in run
     self._target(*self._args, **self._kwargs)
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 2650, in _thread_main
     self.loop_forever(retry_first_connection=True)
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 1481, in loop_forever
     rc = self.loop(timeout, max_packets)
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 1003, in loop
     rc = self.loop_read(max_packets)
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 1284, in loop_read
     rc = self._packet_read()
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 1849, in _packet_read
     rc = self._packet_handle()
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 2305, in _packet_handle
     return self._handle_publish()
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 2500, in _handle_publish
     self._handle_on_message(message)
   File "/usr/local/lib/python3.6/site-packages/paho_mqtt-1.3.1-py3.6.egg/paho/mqtt/client.py", line 2647, in _handle_on_message
     self.on_message(self, self._userdata, message)
   File "/usr/local/lib/python3.6/site-packages/myproject-0.0.1-py3.6.egg/subscribe/client.py", line 60, in on_message
     t.setDaemon(True)
   File "/usr/local/lib/python3.6/threading.py", line 1148, in setDaemon
     self.daemon = daemonic
   File "/usr/local/lib/python3.6/threading.py", line 1141, in daemon
     raise RuntimeError("cannot set daemon status of active thread")
 RuntimeError: cannot set daemon status of active thread

Upvotes: 2

Views: 6853

Answers (1)

Skandix
Skandix

Reputation: 1994

setDaemon should be used before start:

t = Thread(target = test.callmethod,args=(lst[1]))  
t.setDaemon(True) # first
t.start() # second

Upvotes: 4

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