I have a question on LoopCall.
I have a process that uses a sequence of LoopCalls, once one finishes
I call the next to check for the next critical event to continue:
e.g.
def checkForAvailableProfile(self):
profile = fs_profiles_manager.get_next_available_profile()
if profile is None:
return
else:
self.checkForAvailableProfileLoop.stop()
self.profile = profile
logging.debug("using profile: %s", self.profile['name'])
self.ff = FirefoxProcess(self.profile, self.params)
self.ff.run()
self.checkForEventsFileLoop = LoopingCall(self.checkIfEventsFileExists)
self.checkForEventsFileLoop.start(0.5)
self.state = self.STATE_WAIT_FOR_EVENTS
====================================================
The problem is that I'm getting errors, errors when I try to call stop
when stop perhaps has already been called.
I want advice on how to manage LoopCalls. So far I'm using state variables.
e.g.
self.state = self.STATE_WAIT_FOR_EVENTS
if something goes haywire or if the process is done I have a function
that cleans up all the LoopCalls so it's not checking constantly:
def cleanExit(self):
if self.state == self.STATE_WAIT_FOR_PROFILE:
self.checkForAvailableProfileLoop.stop()
elif self.state == self.STATE_WAIT_FOR_EVENTS:
self.checkForEventsFileLoop.stop()
elif self.state == self.STATE_WAIT_FOR_PROC_KILLED:
self.checkIfFirefoxWasKilledLoop.stop()
self.ff.cleanExit()
the above code is what I believe is causing my exceptions, but how
else do I check for the LoopCalls?
=====================================================
2011-08-31 12:30:11-0700 [FiresharkProtocol,1278,127.0.0.1] Unhandled Error
Traceback (most recent call last):
File "/usr/lib/python2.6/dist-packages/twisted/application/app.py",
line 348, in runReactorWithLogging
reactor.run()
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 1170, in run
self.mainLoop()
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 1182, in mainLoop
self.doIteration(t)
File "/usr/lib/python2.6/dist-packages/twisted/internet/selectreactor.py",
line 140, in doSelect
_logrun(selectable, _drdw, selectable, method, dict)
--- <exception caught here> ---
File "/usr/lib/python2.6/dist-packages/twisted/python/log.py",
line 84, in callWithLogger
return callWithContext({"system": lp}, func, *args, **kw)
File "/usr/lib/python2.6/dist-packages/twisted/python/log.py",
line 69, in callWithContext
return context.call({ILogContext: newCtx}, func, *args, **kw)
File "/usr/lib/python2.6/dist-packages/twisted/python/context.py",
line 59, in callWithContext
return self.currentContext().callWithContext(ctx, func, *args, **kw)
File "/usr/lib/python2.6/dist-packages/twisted/python/context.py",
line 37, in callWithContext
return func(*args,**kw)
File "/usr/lib/python2.6/dist-packages/twisted/internet/selectreactor.py",
line 156, in _doReadOrWrite
self._disconnectSelectable(selectable, why, method=="doRead")
File "/usr/lib/python2.6/dist-packages/twisted/internet/posixbase.py",
line 194, in _disconnectSelectable
selectable.connectionLost(f)
File "/usr/lib/python2.6/dist-packages/twisted/internet/tcp.py",
line 519, in connectionLost
protocol.connectionLost(reason)
File "/usr/sbin/fireshark.py", line 101, in connectionLost
self.cleanExit()
File "/usr/sbin/fireshark.py", line 43, in cleanExit
self.checkIfFirefoxWasKilledLoop.stop()
File "/usr/lib/python2.6/dist-packages/twisted/internet/task.py",
line 171, in stop
assert self.running, ("Tried to stop a LoopingCall that was "
exceptions.AssertionError: Tried to stop a LoopingCall that was not running.
2011-08-31 12:30:22-0700 [-] Unhandled error in Deferred:
2011-08-31 12:30:22-0700 [-] Unhandled Error
Traceback (most recent call last):
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 1170, in run
self.mainLoop()
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 1179, in mainLoop
self.runUntilCurrent()
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 778, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py",
line 944, in unwindGenerator
return _inlineCallbacks(None, f(*args, **kwargs), Deferred())
--- <exception caught here> ---
File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py",
line 823, in _inlineCallbacks
3, in _inlineCallbacks
result = g.send(result)
exceptions.AttributeError: 'NoneType' object has no attribute 'send'
2011-08-31 12:30:28-0700 [-] Unhandled error in Deferred:
2011-08-31 12:30:28-0700 [-] Unhandled Error
Traceback (most recent call last):
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 1170, in run
self.mainLoop()
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 1179, in mainLoop
self.runUntilCurrent()
File "/usr/lib/python2.6/dist-packages/twisted/internet/base.py",
line 778, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py",
line 944, in unwindGenerator
return _inlineCallbacks(None, f(*args, **kwargs), Deferred())
--- <exception caught here> ---
File "/usr/lib/python2.6/dist-packages/twisted/internet/defer.py",
line 823, in _inlineCallbacks
result = g.send(result)
exceptions.AttributeError: 'NoneType' object has no attribute 'send'
