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Created on 2011-02-19 16:38 by loewis, last changed 2022-04-11 14:57 by admin. This issue is now closed.
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| File name | Uploaded | Description | Edit | |
| tp_doc.diff | loewis, 2011-02-19 16:38 | |||
| Messages (12) | |||
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| msg128857 - (view) | Author: Martin v. Löwis (loewis) *  |
Date: 2011-02-19 16:38 | |
Currently, memory management for the Py_tp_doc slot in PyType_FromSpec is ill-defined. The doc string being passed is stored in the type object as-is, but later released with PyObject_Free. To make this consistent, PyType_FromSpec should copy the string, so that it's guaranteed that relasing the memory matches allocation. Without this patch, users will have to hold onto the type objects they get from PyType_FromSpec "forever". |
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| msg128858 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2011-02-19 16:44 | |
Sure it should be a blocker? |
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| msg128859 - (view) | Author: Martin v. Löwis (loewis) * |
Date: 2011-02-19 16:48 | |
If this isn't added, people using the API might see crashes. If they then work around crashes, they will see memory leaks in future releases. |
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| msg128860 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2011-02-19 17:00 | |
Well, isn't Py_tp_doc characteristically bound to a constant char *, so that the problem doesn't manifest itself? |
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| msg128863 - (view) | Author: Georg Brandl (georg.brandl) * |
Date: 2011-02-19 17:26 | |
Sounds like a blocker to me. Martin, will you be able to provide a patch before final? |
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| msg128871 - (view) | Author: Martin v. Löwis (loewis) * |
Date: 2011-02-19 18:25 | |
> Well, isn't Py_tp_doc characteristically bound to a constant char * That's exactly the problem: PyType_FromSpec puts in this string literal. When the type is later released, PyObject_Free is called in type_dealloc, which segfaults. |
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| msg128872 - (view) | Author: Martin v. Löwis (loewis) * |
Date: 2011-02-19 18:26 | |
> Sounds like a blocker to me. Martin, will you be able to provide a patch before final? The attached patch works fine for me. |
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| msg128873 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2011-02-19 18:34 | |
> > Sounds like a blocker to me. Martin, will you be able to provide a patch before final? > > The attached patch works fine for me. Is there some documentation somewhere for all this? |
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| msg128879 - (view) | Author: Martin v. Löwis (loewis) * |
Date: 2011-02-19 19:39 | |
>>> Sounds like a blocker to me. Martin, will you be able to provide a patch before final? >> >> The attached patch works fine for me. > > Is there some documentation somewhere for all this? Can you please be more specific? What's "all this"? That tp_doc will be copied is currently undocumented. PyType_FromSpec is documented in the PEP. |
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| msg128880 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2011-02-19 19:41 | |
> >>> Sounds like a blocker to me. Martin, will you be able to provide a patch before final? > >> > >> The attached patch works fine for me. > > > > Is there some documentation somewhere for all this? > > Can you please be more specific? What's "all this"? > > That tp_doc will be copied is currently undocumented. PyType_FromSpec > is documented in the PEP. I meant all of py_tp_doc, "limited api", "restricted api" show almost zero hits in the API docs. A PEP is nice but I'm not sure many people spontaneously read PEPs. |
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| msg128881 - (view) | Author: Martin v. Löwis (loewis) * |
Date: 2011-02-19 19:48 | |
>> That tp_doc will be copied is currently undocumented. PyType_FromSpec >> is documented in the PEP. > > I meant all of py_tp_doc, "limited api", "restricted api" show almost > zero hits in the API docs. A PEP is nice but I'm not sure many people > spontaneously read PEPs. No, there is no documentation in the Doc directory. I *would* expect that people interested in using the stable ABI do find the PEP and read it. With the exception of this issue, I consider the PEP to be complete and correct documentation (of course, it probably contains errors that I'm unaware of). However, documentation for the PEP 384 changes seems to be an unrelated issue. |
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| msg128882 - (view) | Author: Georg Brandl (georg.brandl) * |
Date: 2011-02-19 21:47 | |
OK, committed in r88443 (with error handling made more consistent). BTW, the return from PyType_GenericAlloc isn't NULL-checked, which looks like a potential crasher to me. Not release-critical though. |
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