"Asaf Las" <roeg...@gmail.com> wrote in message news:58c541ab-c6e1-45a8-b03a-8597ed7ec...@googlegroups.com... > > Yes the question was about CPython. But i am not after CPython leaks > though detecting these would be good, but my own mistakes leading to > accumulation of data in mutable structures. > there will be few processes running python code standalone communicating > across servers and every activity will be spread over time so > i have to persistently keep record of activity and remove it later when > activity is finished.
I had a similar concern. My main worry, which turned out to be well-founded, was that I would create an object as a result of some user input, but when the user had finished with it, and in theory it could be garbage-collected, in practice it would not be due to some obscure circular reference somewhere. For short-running tasks this is not a cause for concern, but for a long-running server these can build up over time and end up causing a problem. My solution was to log every time an object was created, with some self-identifying piece of information, and then log when it was deleted, with the same identifier. After running the program for a while I could then analyse the log and ensure that each creation had a corresponding deletion. The tricky bit was logging the deletion. It is a known gotcha in Python that you cannot rely on the __del__ method, and indeed it can cause a circular reference in itself which prevents the object from being garbage-collected. I found a solution somewhere which explained the use of a 'delwatcher' class. This is how it works - class MainObject: def __init__(self, identifier): self._del = delwatcher('MainObject', identifier) class delwatcher: def __init__(self, obj_type, identifier): self.obj_type = obj_type self.identifier = identifier log('{}: id={} created'.format(self.obj_type, self.identifier)) def __del__(self): log('{}: id={} deleted'.format(self.obj_type, self.identifier)) In this case calling __del__() is safe, as no reference to the main object is held. If you do find that an object is not being deleted, it is then trial-and-error to find the problem and fix it. It is probably a circular reference HTH Frank Millman -- https://mail.python.org/mailman/listinfo/python-list