Wait before resuming a task (without sleep)

Question

I am trying to do a simple task: Waiting.

Here is an example :

# Inform the user about the closing
new_message = Message.objects.create(content='Game closing in 10 seconds...', game=self)
new_message.save()   

time.sleep(10)

# After waiting, delete the game
self.delete()

However, my host only allows me 1 worker process, hence, if I decide to use sleep, every other requests will be freezed and my app will become unresponsive to the users.

Is there a way to work around this problem? Also, I can't use threads in case of