I also found it strange that i get no error message whatsoever. I was always running POX with --verbose plus log.level —DEBUG, and i did not use .raiseEventNoErrors() method.
I haven't really given much thought on how i want the events to be raised, i experimented a little in order to find a way that works. Adding the CustomEvent, in the _eventMixin set of OpenFlowNexus and did the trick. In the end it doesn’t really matter for me which way the event is raised. I have a module, with 2 distinct functions. 1. Flow removal that is called automatically 2. Flow insertion that has to be manually called everywhere a new flow is added. I used the same logic as FlowRemoved, PacketIn e.t.c. events/handlers, so i added the following lines in of_01.py def handle_CUSTOM_EVENT (con, msg): #A > e = con.ofnexus.raiseEvent( > CustomEvent, con, msg) > if e is None or e.halt != True: > con.raiseEvent(CustomEvent, con, msg) > and in order to call the above (e.g. l2_learning): of_01.handle_CUSTOM_EVENT(event.connection, msg) > The above doesn't work unless i delete the arguments in handle_CUSTOM_EVENT(). Traceback is: File "/home/mininet/pox/pox/lib/revent/revent.py", line 234, in > raiseEventNoErrors > > return self.raiseEvent(event, *args, **kw) > > File "/home/mininet/pox/pox/lib/revent/revent.py", line 281, in > raiseEvent > > rv = event._invoke(handler, *args, **kw) > > File "/home/mininet/pox/pox/lib/revent/revent.py", line 159, in _invoke > > return handler(self, *args, **kw) > > File "/home/mininet/pox/pox/forwarding/l2_learning.py", line 182, in > _handle_PacketIn > > of_01.handle_CUSTOM_EVENT(event.connection, msg) > > File "/home/mininet/pox/pox/openflow/of_01.py", line 68, in > handle_CUSTOM_EVENT > > e = con.ofnexus.raiseEvent(CustomEvent, con, msg) > > File "/home/mininet/pox/pox/lib/revent/revent.py", line 265, in > raiseEvent > > event = eventType(*args, **kw) > > TypeError: __init__() takes exactly 1 argument (3 given) > >From what i understand raiseEvent method expects 1 argument but receives 3. I don't understand however why handle_PACKET_IN/FLOW_REMOVED get to .raiseEventNoErrors the exact same way, and no TypeError occurs. Truth is i don't need the connection part, but is necessary for my module that the msg.match object representing the flow that is installed is passed to the handler. def _handle_CustomEvent(self, msg): > I don’t know if what i did is conceptually correct or if there is a cleaner way (programming-wise). I just thought that using a separate module instead of hard-coding the actions i need executed was better, considering i will also be able to pass some arguments from the CLI to the module less painfully, e.g. misc.CustomModule --<server>_<hostname>. I would greatly appreciate your opinion on this. Thanks for all your help so far, Adam Pavlidis On Tue, Nov 4, 2014 at 12:42 AM, Murphy McCauley <murphy.mccau...@gmail.com> wrote: > I'm a bit surprised that you're getting no result at all as opposed to, > say, exceptions in the POX log. Have you tried turning logging to DEBUG > level and reading through to make sure there are no hints as to what might > be going wrong? It's possible that raiseEventNoErrors() is masking the > exceptions. You might try at least temporarily replacing such calls with > just plain raiseEvent(). > > It looks like you want these events to be raised using the same sources as > normal OpenFlow events. Normally, sources need to be aware of the events > they'll be raising. In your case, these sources are the Connection (in > of_01) and OpenFlowNexus (in openflow/__init__) classes. Have you added > your event to their set of _eventMixin_events? > > On Nov 3, 2014, at 2:15 AM, Adam Pavlidis <adampavli...@gmail.com> wrote: > > > Hello, > > > > i am trying to implement a controller module that handles two types of > Events: > > the already existing FlowRemoved and another of my own creation > > "CustomEvent" that i will execute in various circumstances. > > > > I have read the section on custom events contained in the POX manual > > ( > https://openflow.stanford.edu/display/ONL/POX+Wiki#POXWiki-TheEventSystem%3Apox.lib.revent > > ) > > and have successfully executed the examples. > > > > I have looked up a bit how the POX raises events such as PacketIn. > > I added the following lines of code in pox/pox/openflow/__init__.py > > > > class CustomEvent(Event): > > """ > > Our own custom event > > """ > > def __init__(self): > > Event.__init__(self) > > > > Then i added a handler for that event in an already existing controller > module, > > > > def _handle_CustomEvent (self, event): > > log.debug('The Event was raised successfully') > > > > However when i manually raise the above event, > > (e.g. during the handling of a PacketIn event in > > forwarding.l2_learning) nothing happens. > > I used both the method explained in the manual (creating a subclass of > > EventMixin with _eventMixin_set=([CustomEvent], creating an instance > > of that class and raising the event on that instance), and the > > core.raiselater method. > > > > Important note: In the same module there is a handler for FlowRemoved > > Events, that is notified without issues, when a flow is removed from the > > switch, so i don't think there is a listener issue. > > > > In my efforts to find the problem i tried to experiment in > > openflow/of_01.py and specifically in lines 85, 177 where FlowRemoved > > and PacketIn events are raised from the Controller, i tried to force > > raise my own > > event when a PacketIn was supposed to be raised. > > > > def handle_PACKET_IN (con, msg): #A > > e = con.ofnexus.raiseEventNoErrors(CustomEvent, con, msg) > > if e is None or e.halt != True: > > con.raiseEventNoErrors(CustomEvent, con, msg) > > > > Nothing happened either (apart from losing connectivity between the > hosts). > > > > I would appreciate any help, > > Adam Pavlidis > >
