Celery periodic_task in Django run once(!)

Celery periodic_task in Django run once(!)

I am creating a periodic_task using celery and Django which I want to run
every X seconds.. The task should spawn a couple of sub-tasks, but I need
to make sure only one set of sub-tasks are spawned for each main task.
This is what I have..
@periodic_task(run_every=datetime.timedelta(seconds=2))
def initialize_new_jobs():
for obj in Queue.objects.filter(status__in=['I', 'Q']):
obj = Queue.objects.get(id=obj.id)
if obj.status not in ['I', 'Q']:
continue
obj.status = 'A'
obj.save()
create_other_task.delay(obj.id)
This kinda works, but feels wrong. I haveto refresh obj at the beginning
of the loop to make sure another running periodic_task isnt issuing
create_other_task on the same Queue object.
Is there any better way of doing this kind of job? Basically, I want to do
create_other_task as often as possible, but only ONCE per Queue object
with status I or Q.
This is a shortened version of my problem, so please ignore the fact that
I could just run create_other_task when creating the Queue object, instead
of running the periodic task :)