Jeroen Demeyer schrieb am 05.10.2015 um 16:04: > I'm not entirely sure if this is a feature or bug... > > I noticed that, if a __cinit__ call raises an exception on an object, that > __dealloc__ on that same object is still called. > > The problem is that __cinit__ is supposed to set up the C-level attributes > for that object. If this somehow fails, then the object isn't in a > consistent state yet, so it makes no sense to call __dealloc__ on it. > > Do you consider this a Cython bug or should I manually protect my code > against this?
In addition to what was already answered, note that __cinit__() is called *after* the CPython instantiation of the class, so the object is fully alive at that point. If the error happens in the middle of an inheritance chain, then the object is created and the upper __cinit__() methods have run, but the lower ones have not and will not be. Since the overall process failed, the object is collected immediately and the __dealloc__() methods are called, all of them, one after the other. Calling no __dealloc__() methods at all would be wrong here and easily leads to resource leaks. But trying to decide in such a case which __dealloc__() methods to call and which not would just make things overly complex and potentially difficult to understand. Calling all of them and letting users guard against uninitialised fields is much simpler, also handles other error cases at the user level and is generally more predictable for all sides. Stefan _______________________________________________ cython-devel mailing list cython-devel@python.org https://mail.python.org/mailman/listinfo/cython-devel
