On Apr 28, 12:02 am, Chris Rebert <c...@rebertia.com> wrote: > On Tue, Apr 27, 2010 at 2:58 PM, Chris Rebert <c...@rebertia.com> wrote: > > On Tue, Apr 27, 2010 at 2:42 PM, Michal M <mich.mier...@googlemail.com> > > wrote: > >> On 27 Kwi, 23:21, Duncan Booth <duncan.bo...@invalid.invalid> wrote: > >>> Michal M <mich.mier...@googlemail.com> wrote: > >>> > I've just found out that one of objects is not destroyed when it > >>> > should be. This means that something was holding reference to this > >>> > object or part of it (i.e. method). Is there any way to check what > >>> > holds that reference? I am unable to do that just looking to the code > >>> > or debugging it because it is pretty complicated, but I am able to > >>> > invoke this situation again. > > >>> See if this code helps: > > >>>http://groups.google.com/group/comp.lang.python/browse_thread/thread/... > > >>> It's pretty old so it may need some adjustment, but I wrote it > >>> to figure out exactly that sort of problem. > > >> Thanks you for answers. > >> I tried to use gc.get_referrers(self) in point in code when according > >> to me object should be destroyed earlier but I did not see anything > >> interesting. Then just realised that gc will not destroy object even > >> when itself holds reference to his own method. > > >> For example > > >> class A(object): > >> def a(self): > >> pass > >> def b(self): > >> self.method = self.a > >> def __del__(self): > >> print "A object deleted" > > >>>> a = A() > >>>> del a > >> A object delted > >>>> a = A() > >>>> a.b() > >>>> del a > >> ... nothing ... > > >> I thought gc would discover such circle loops but apparently it did > >> not. > > > No, it does, you just didn't give it long enough; for performance > > reasons, cyclical GC is only done every so often: > > Addendum: > Also, defining __del__ in your example was likely problematic: > Seehttp://docs.python.org/library/gc.html#gc.garbage > > - Chris
Thanks, specially for pointing the last issue with __del__ - I missed that! -- http://mail.python.org/mailman/listinfo/python-list
