Hi, On Sun, 04 Aug 2013 09:23:41 +0200 Stefan Behnel <stefan...@behnel.de> wrote: > > I'm currently catching up on PEP 442, which managed to fly completely below > my radar so far. It's a really helpful change that could end up fixing a > major usability problem that Cython was suffering from: user provided > deallocation code now has a safe execution environment (well, at least in > Py3.4+). That makes Cython a prime candidate for testing this, and I've > just started to migrate the implementation.
That's great to hear. "Safe execution environment" for finalization code is exactly what the PEP is about. > One thing that I found to be missing from the PEP is inheritance handling. > The current implementation doesn't seem to care about base types at all, so > it appears to be the responsibility of the type to call its super type > finalisation function. Is that really intended? Yes, it is intended that users have to call super().__del__() in their __del__ implementation, if they want to call the upper-level finalizer. This is exactly the same as in __init__() and (most?) other special functions. > Another bit is the exception handling. According to the documentation, > tp_finalize() is supposed to first save the current exception state, then > do the cleanup, then call WriteUnraisable() if necessary, then restore the > exception state. > > http://docs.python.org/3.4/c-api/typeobj.html#PyTypeObject.tp_finalize > > Is there a reason why this is left to the user implementation, rather than > doing it generically right in PyObject_CallFinalizer() ? That would also > make it more efficient to call through the super type hierarchy, I guess. I > don't see a need to repeat this exception state swapping at each level. I didn't give much thought to this detail. Originally I was simply copying this bit of semantics from tp_dealloc and tp_del, but indeed we could do better. Do you want to open an issue about it? Regards Antoine. _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
