Message 352672 - Python tracker

Message352672

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Author	ammar2
Recipients	ammar2, docs@python
Date	2019-09-17.23:27:39
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1568762859.98.0.230733966822.issue38206@roundup.psfhosted.org>
In-reply-to

Content
When dealing with a heap allocated type (https://docs.python.org/3/c-api/typeobj.html#Py_TPFLAGS_HEAPTYPE / PyType_FromSpec), if the type has a custom tp_dealloc function then it MUST decrement the references to the type object itself due to this code block: https://github.com/python/cpython/blob/4a12a178f4a6b9a59d97fecc727f2b6b28dfc85f/Objects/typeobject.c#L1189-L1192 The only mention of this is within the whatsnew entry for 3.8: https://github.com/python/cpython/commit/364f0b0f19cc3f0d5e63f571ec9163cf41c62958#diff-77c703d9a958f6a4b0dc2f692b3fd5b3 This error was made in https://github.com/python/cpython/pull/16127#pullrequestreview-288312751 and https://github.com/python/cpython/pull/16071#pullrequestreview-287819525 It seems like a common pitfall, let's add a note about this in the doc.

Content

When dealing with a heap allocated type (https://docs.python.org/3/c-api/typeobj.html#Py_TPFLAGS_HEAPTYPE / PyType_FromSpec), if the type has a custom tp_dealloc function then it MUST decrement the references to the type object itself due to this code block: https://github.com/python/cpython/blob/4a12a178f4a6b9a59d97fecc727f2b6b28dfc85f/Objects/typeobject.c#L1189-L1192

The only mention of this is within the whatsnew entry for 3.8: https://github.com/python/cpython/commit/364f0b0f19cc3f0d5e63f571ec9163cf41c62958#diff-77c703d9a958f6a4b0dc2f692b3fd5b3

This error was made in https://github.com/python/cpython/pull/16127#pullrequestreview-288312751 and https://github.com/python/cpython/pull/16071#pullrequestreview-287819525

It seems like a common pitfall, let's add a note about this in the doc.

History
Date	User	Action	Args
2019-09-17 23:27:40	ammar2	set	recipients: + ammar2, docs@python
2019-09-17 23:27:39	ammar2	set	messageid: <1568762859.98.0.230733966822.issue38206@roundup.psfhosted.org>
2019-09-17 23:27:39	ammar2	link	issue38206 messages
2019-09-17 23:27:39	ammar2	create