New submission from Jeroen Ruigrok van der Werven: Quoting from my email to Raymond:
In the Trac/Genshi community we've been tracking a bit obscure memory leak that causes us a lot of problems. Please see http://trac.edgewall.org/ticket/6614 and then http://genshi.edgewall.org/ticket/190 for background. We reduced the case to the following Python only code and believe it is a bug within itertool's groupby. As Armin Ronacher explains in Genshi ticket 190: "Looks like genshi is not to blame. itertools.groupby has a grouper with a reference to the groupby type but no traverse func. As soon as a circular reference ends up in the groupby (which happens thanks to the func_globals in our lambda) genshi leaks." This can be demonstrated with the following code (testcase attachment present with this issue): import gc from itertools import groupby def run(): keyfunc = lambda x: x for i, j in groupby(range(100), key=keyfunc): keyfunc.x = j for x in xrange(20): gc.collect() run() print len(gc.get_objects()) On executing this in will show numerical output of the garbage collector, but every iteration will be +4 from the previous, as Armin specifies: "a frame, a grouper, a keyfunc and a groupby object" We have been unable to come up with a decent patch and thus I am logging this issue now. ---------- files: testcase.py messages: 63332 nosy: asmodai, rhettinger severity: normal status: open title: itertools.groupby() leaks memory with circular reference type: resource usage versions: Python 2.4, Python 2.5, Python 2.6, Python 3.0 Added file: http://bugs.python.org/file9624/testcase.py __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue2246> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
