Hello, The new test_importlib.extension.test_loader is currently leaking references, (issue24268). There is a simple hack to stop this, but I'm inclined to not apply quick hacks and rather dig into the root cause. (It's a test module, the refleaks are relatively harmless.)
The tests are based directly on the "xxlimited" example, xxlimited.Xxo, which exhibits the same bug -- it's just not tested. It's is caused by a combination of a few factors, but I'm not sure what's a bug and what's just undocumented behavior, so I'm asking for input to put me on the right track. As reported in issue16690, heap types with a naïve custom tp_dealloc leak references to the type when instantiated. According to [0], it seems that tp_dealloc should check if it has been overridden, and if so, decref the type. This needs to be documented (regardless of the solution to the other problems), and I intend to document it. We can change xxlimited to do the check and decref, but isn't it too ugly for a module that showcases the extension module API? (xxlimited.Xxo can technically skip the check, since it doesn't allow subclasses, but that would be setting a nasty trap for anyone learning from that example.) The nice way out would be taking advantage of PEP 442: xxlimited.Xxo can ditch tp_dealloc in favor of tp_traverse and tp_finalize (the former of which it needs anyway to behave correctly). Unfortunately, tp_finalize is not available in the stable ABI (issue24345). I think it should be added; is it too late for 3.5? Another problem is that xxlimited is untested. It's only built for non-debug builds, because Py_LIMITED_API and Py_DEBUG are incompatible. Would it make sense to build and test it without Py_LIMITED_API in debug mode, instead of not building it at all? [0] http://bugs.python.org/issue15653#msg168449 _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
