In my Django application I need to schedule some tasks to run in future. Celery is not an option here because some crucial options - mainly, the ability to revoke() a task - are only available with fully-featured MQ backend and I only have a limited shared hosting where I can't install this kind of software. After some reading, I've found that supposedly "right" way to do that in Python is to spawn a subprocess and call sleep(). However, spawning a process does have an overhead, especially considering a rather simple nature of tasks I want to defer (retrieval and conditional deletion of one object).
Then I decided to use threads instead. They have little to no overhead, share memory and Python has a nice little threading.Timer class which is exactly what I need. My code looks like this: http://pastebin.com/K6RukAX9 Here's when my questions come in. I admit my knowledge of threading is somewhat low and Python operates on high-level too, so nuances are not easily noticeable. From what I've learned, threads (can?) share memory with main thread/process. My primary concern here is that, as far as I understand, method=prefork (the default) creates a pool of processes waiting for work. It seems possible that it may impact my scheduler somehow, i.e. if process that spawned it sits idle (sleeps?) when countdown ends. On the other hand, threaded mode is supposedly more efficient because, being free from overhead of process forking, it can create child threads at will. In my mind this raises a similar concern to above: what if framework decides to destroy a thread that happens to be the one where Timer has been previously spawned? It is entirely possible that my concerns are completely baseless and both methods have nothing to do with my scheduler. I'm asking for input from smarter people than me :) Regards, Peter -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-users. For more options, visit https://groups.google.com/groups/opt_out.
