I need to put messages into a queue from within a Zclass, and then get and process them from an external long running process.
When you say an external long running process, do you mean that you'll want to access them from a separate process via something like XML-RPC? or ZEO? Or HTTP? What is your preferred way to get access to the items in the queue?
I have created a class which imports a derivative of queue, the class instantiates a queue as a class object. The idea is that the queue will use a persistent object for the queue (list), and then some external process can also use the same object(list) in its queue processing. Both the zclasses that inherit from this queue and the external process must use the same mutexes...
I dont think you mean external process here, I think you might mean something else... two processes can not share the same mutex. Do you maybe mean thread?
Questions: 1 Should the queue.queue object be made persistent or should we instantiate it with an external list which is the persistent object. Can either of these be done an how.
I think you could probably wrap the Queue class in a persistent wrapper... that'd work. Anything that can be pickled can be made persistent, so as long as the Queue class doesnt have a subobject that can't be pickled, you can make it persistent. You'll need to write a Python product to do so (see the Zope developer's Guide).
2. Assuming we can do something like the above what are the considerations wrt package distribution.
None, really... if you intend to share just the class data. If you intend to share exports of instance data (the queues themselves), not much of an issue here either... just need to make sure that each Zope you run on has the Product you create. HTH, - C