Message 68126 - Python tracker

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In-reply-to
Author	Rhamphoryncus
Recipients	Rhamphoryncus
Date	2008年06月13日.05:14:50
SpamBayes Score	0.04756887
Marked as misclassified	No
Message-id	<1213334091.99.0.730324798344.issue3100@psf.upfronthosting.co.za>

Content
1. MyRef is released from the module as part of shutdown 2. MyRef's subtype_dealloc DECREFs its dictptr (not clearing it, as MyRef is dead and should be unreachable) 3. the dict DECREFs the Dummy (MyRef's target) 4. Dummy's subtype_dealloc calls PyObject_ClearWeakRefs to notify of its demise 5. the callback is called, with the dead MyRef as an argument 6. If MyRef's dict is accessed a segfault occurs. Presumably just calling the callback does enough damage to explain the segfault without accessing MyRef's dict. As I understand, a deleted weakref doesn't call its callback. However, subtype_dealloc doesn't call the base type's tp_dealloc until after it does everything else. Does it need a special case for weakrefs, or maybe a tp_predealloc slot?

Content

1. MyRef is released from the module as part of shutdown
2. MyRef's subtype_dealloc DECREFs its dictptr (not clearing it, as
MyRef is dead and should be unreachable)
3. the dict DECREFs the Dummy (MyRef's target)
4. Dummy's subtype_dealloc calls PyObject_ClearWeakRefs to notify of its
demise
5. the callback is called, with the dead MyRef as an argument
6. If MyRef's dict is accessed a segfault occurs. Presumably just
calling the callback does enough damage to explain the segfault without
accessing MyRef's dict.
As I understand, a deleted weakref doesn't call its callback. However,
subtype_dealloc doesn't call the base type's tp_dealloc until *after* it
does everything else. Does it need a special case for weakrefs, or
maybe a tp_predealloc slot?

History
Date	User	Action	Args
2008年06月13日 05:14:52	Rhamphoryncus	set	spambayes_score: 0.0475689 -> 0.04756887 recipients: + Rhamphoryncus
2008年06月13日 05:14:52	Rhamphoryncus	set	spambayes_score: 0.0475689 -> 0.0475689 messageid: <1213334091.99.0.730324798344.issue3100@psf.upfronthosting.co.za>
2008年06月13日 05:14:51	Rhamphoryncus	link	issue3100 messages
2008年06月13日 05:14:50	Rhamphoryncus	create

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