On Saturday, October 25, 2014, Stefan Richthofer <stefan.richtho...@gmx.de> wrote:
> Okay, sorry, I was thinking too Jython-like. I fixed runGC() just to > see now that it does not even trigger resurrection, since under > CPython there are no finalizers executed in ref cycles (i.e. I find my > objects in gc.garbage). > So I realize, my xy_cyclic tests are pointless anyway since in cyclic > gc no resurrection can happen. > > > The second problem (with weakref) is different: weakrefs are cleared > > before __del__ is called, so resurrection doesn't affect the whole > > process. > It appears weakrefs are only cleared if this is done by gc (where no > resurrection can happen anyway). If a resurrection-performing-__del__ is > just called by ref-count-drop-to-0, weakrefs persist - a behavior that is > very difficult and inefficient to emulate in Jython, but I'll give it > some more thoughts... > > You shouldn't have to emulate that. The exact behavior of GC is allowed to vary between systems. > However thanks for the help! > > -Stefan > > > > Gesendet: Sonntag, 26. Oktober 2014 um 01:22 Uhr > > Von: "Antoine Pitrou" <solip...@pitrou.net <javascript:;>> > > An: python-dev@python.org <javascript:;> > > Betreff: Re: [Python-Dev] results of id() and weakref.getweakrefs() > sometimes break on object resurrection > > > > > > Hello Stefan, > > > > On Sun, 26 Oct 2014 00:20:47 +0200 > > "Stefan Richthofer" <stefan.richtho...@gmx.de <javascript:;>> wrote: > > > Hello developers, > > > > > > I observed strange behaviour in CPython (tested in 2.7.5 and 3.3.3) > > > regarding object resurrection. > > > > Your runGC() function is buggy, it does not run the GC under CPython. > > Fix it and the first problem (with id()) disappears. > > > > The second problem (with weakref) is different: weakrefs are cleared > > before __del__ is called, so resurrection doesn't affect the whole > > process. Add a callback to the weakref and you'll see it is getting > > called. > > > > In other words, CPython behaves as expected. Your concern is > > appreciated, though. > > > > Regards > > > > Antoine. > > > > > > _______________________________________________ > > Python-Dev mailing list > > Python-Dev@python.org <javascript:;> > > https://mail.python.org/mailman/listinfo/python-dev > > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/stefan.richthofer%40gmx.de > > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org <javascript:;> > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/guido%40python.org > -- --Guido van Rossum (on iPad)
_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
