Hi
I am using twistd to run a daemon which manage a device
The issue occur in a LoopingCall
# Create a looping call and assign waiting_update function to it
self.waiting_loop = task.LoopingCall(self.waiting_update)
def send(self):
# If client isn't waiting for response and frame queue of the
NetworkManager is not empty :
if not self.waiting_response and self.network_manager.queue:
# If first element of the queue is None :
if self.network_manager.queue[0] == None:
# Delete first element
del self.network_manager.queue[0]
# Recall the function
self.send()
# If first element of the queue is different than None :
else:
# Copy first element of the queue
frame = self.network_manager.queue[0]
# If debug is enabled print debugging string and frame
if self.network_manager.debug:
print(self.network_manager.lang['keypanel_sending_frame'], "
".join(frame[i:i+2] for i in range(0, len(frame), 2)))
# Send frame to the KeyPanel
self.transport.write(bytes.fromhex(frame))
# Set waiting response to True
self.waiting_response = True
def print_test(self):
print ("Test errback ")
# If loop isn't already running, start the loop
if not self.waiting_loop.running:
self.waiting_time = time.time()
d = self.waiting_loop.start(1)
d.addErrback(print_test)
def waiting_update(self):
# If waiting time is equal or greater than the limit :
if time.time() >= self.waiting_time +
self.network_manager.waiting_response_time:
# Increment retry by 1
self.retry += 1
# If retry is equal or greater than the limit :
if self.retry >= self.network_manager.send_retry_max:
# If debug is enabled print debugging string
if self.network_manager.debug:
print(self.network_manager.lang['keypanel_fail_sending_frame'],
self.network_manager.queue[0])
# Delete first element of the NetworkManager queue
del self.network_manager.queue[0]
# Reset retry variable
self.retry = 0
# Reset waiting state
self.waiting_reset()
# If waiting time is lesser than the limit :
else:
# Waiting 1/2 second
time.sleep(0.5)
# Increment waiting time
self.waiting_time = time.time()
def waiting_reset(self):
# Disable response waiting
self.waiting_response = False
# Stop the loop
self.waiting_loop.stop()
# Reset waiting time
self.waiting_time = time.time()
# Send the next frame in the queue
self.send()
When the internet connection is good everything works but if the cable
is disconnected an error occurs in twisted.internet.defer which I can't
catch
Error message is
[twisted.internet.defer#critical] Unhandled error in Deferred:
[twisted.internet.defer#critical]
Traceback (most recent call last):
File "/usr/local/lib/python3.7/dist-packages/twisted/internet/base.py",
line 913, in runUntilCurrent call.func(*call.args, **call.kw)
File "/usr/local/lib/python3.7/dist-packages/twisted/internet/task.py",
line 241, in __call__ d.addErrback(eb)
File "/usr/local/lib/python3.7/dist-packages/twisted/internet/defer.py",
line 333, in addErrback errbackKeywords=kw)
File "/usr/local/lib/python3.7/dist-packages/twisted/internet/defer.py",
line 311, in addCallbacks self._runCallbacks()
--- <exception caught here> ---
File "/usr/local/lib/python3.7/dist-packages/twisted/internet/defer.py",
line 654, in _runCallbacks current.result = callback(current.result,
*args, **kw)
File "/usr/local/lib/python3.7/dist-packages/twisted/internet/task.py",
line 236, in eb
d.errback(failure) builtins.AttributeError: 'NoneType' object has no
attribute 'errback'
Do you have a proposal to resolve this issue
Thank you
