On 12/27/05, Jesus Cea <jcea@argo.es> wrote:
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Wow, Andrea Arcangeli, of Linux Kernel fame. What an honor :).
+ import gc + gc.collect()
Haha. I was just writing you about manual garbage collector invocations.
Manual collections can be costly, nevertheless. Since the manual collector is only needed to free cyclic references, I guess that Twisted people would rather prefer a patch to break cyclic references in Twisted code. For example, using "__del__" methods or "weakref".
You can easily see what objects and references keep the cycles alive using "gc.garbage" and "gc.get_referrers()". Usually a single "a.value=None" can do miracles :-). Weakref can be very very helpful, also.
Just some points of clarification, as I don't think Jesus has got the whole story: - gc.collect() is the equivalent of what's run occassionally by Python. So explicitly calling it is *not* required to break all circular references. In this case, it only helped because Andrea was accumulating objects quicker than the Python-scheduled gc.collect was being run. - I really doubt we need a patch to Twisted to break any cyclic references. :) - gc.garbage contains what _won't_ be collected by a call to gc.collect(). gc.garbage contains only broken cycles (e.g., those with objects that have __del__ methods), not all cycles. - Ever since the new gc system was enabled by default in Python, it should never be necessary to manually break cycles unless you have __del__ crap involved. -- Twisted | Christopher Armstrong: International Man of Twistery Radix | -- http://radix.twistedmatrix.com | Release Manager, Twisted Project \\\V/// | -- http://twistedmatrix.com |o O| | w----v----w-+