Message 351099 - Python tracker

Message351099

Author	vstinner
Recipients	Mark.Shannon, christian.heimes, jdemeyer, lukasz.langa, pablogsal, petr.viktorin, pitrou, vstinner
Date	2019-09-03.19:30:28
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1567539029.24.0.634351307567.issue38006@roundup.psfhosted.org>
In-reply-to

Content
collect() of gcmodule.c: * collect() builds an "unreachable" list which is quite important in this bug * the bug occurs in delete_garbage() which uses the unreachable list * weak references part of unreachable are handled before delete_garbage() in handle_weakrefs(): "Clear weakrefs and invoke callbacks as necessary". It seems like reproducer.tar.gz and gc_crash.py crashes involve a reference cycle. reproducer.tar.gz uses a weak reference which is not part of the reference cycle.

Content

collect() of gcmodule.c:

* collect() builds an "unreachable" list which is quite important in this bug
* the bug occurs in delete_garbage() which uses the unreachable list
* weak references part of unreachable are handled before delete_garbage() in handle_weakrefs(): "Clear weakrefs and invoke callbacks as necessary".

It seems like reproducer.tar.gz and gc_crash.py crashes involve a reference cycle.

reproducer.tar.gz uses a weak reference which is *not* part of the reference cycle.

History
Date	User	Action	Args
2019-09-03 19:30:29	vstinner	set	recipients: + vstinner, pitrou, christian.heimes, petr.viktorin, lukasz.langa, Mark.Shannon, jdemeyer, pablogsal
2019-09-03 19:30:29	vstinner	set	messageid: <1567539029.24.0.634351307567.issue38006@roundup.psfhosted.org>
2019-09-03 19:30:29	vstinner	link	issue38006 messages
2019-09-03 19:30:29	vstinner	create