Christian Tismer <tis...@stackless.com> added the comment:
The default of PyType_FromSpec for tp_dealloc is wrong! ------------------------------------------------------- After a long struggle with crashes and leaks, the situation was finally clarified: When a type is converted from a static type to a heaptype via PyType_FromSpec, and the tp_dealloc field is NULL, then subtype_dealloc is inserted. This is not correct. The reasoning in the code is that a heaptype has subtype_dealloc. But before the conversion, the type was static, and for static types the function object_dealloc was inserted. In the given type, the only change is to become a heaptype. The by default inserted object_dealloc should not be changed, since the existing code was written with object_dealloc in mind and not the consequences of replacing it with subtype_dealloc. Before this solution, I used a dummy function to prevend subpype_dealloc being inserted, but that caused leaks. It was hard to understand that the default for a static type is object_dealloc. After that, it was easy to fix that: The now correctly working workaround is to explicitly insert an object_dealloc function whenever the default for tp_dealloc is NULL. Again, in order to use this fix, it is necessary to break the Limited API, because in order to write an object_dealloc function (it is not public) you need access to type objects. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue26979> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
