On 23 April 2012 09:42, Stefan Behnel <stefan...@behnel.de> wrote: > Stefan Behnel, 23.04.2012 10:23: >> mark florisson, 22.04.2012 16:41: >>> On 22 April 2012 15:31, mark florisson wrote: >>>> I think the problem here >>>> is that a single memoryview object is traversed multiple times through >>>> different traverse functions, and that the refcount doesn't match the >>>> number of traverses. Indeed, the refcount is only one, as the actual >>>> count is the acquisition count. So we shouldn't traverse the >>>> memoryview objects in memoryview slices, i.e. not >>>> _memoryviewslice.from_slice.memview. I'll come up with a commit >>>> shortly, would you be willing to test it? >>> >>> BTW, tp_clear calls Py_CLEAR on Py_buffer.obj, shouldn't it call >>> releasebuffer instead? >> >> Where is that? The memoryview class calls __Pyx_ReleaseBuffer() here. > > Ah, found it. Yes, tp_clear() would be called before __dealloc__() in > reference cycles, so that's a problem. I'm not sure tp_clear should do > something as (potentially) involved as freeing the buffer, but if the > Py_buffer is owned by the object, then I guess it just has to do that. > Otherwise, it would leak the buffer. > > The problem is that this also impacts user code, though, so a change might > break code, e.g. when it needs to do some cleanup on its own before freeing > the buffer. It would make the code more correct, sure, but it would still > break it. Guess we have to take that route, though... > > Stefan > _______________________________________________ > cython-devel mailing list > cython-devel@python.org > http://mail.python.org/mailman/listinfo/cython-devel
It also seems that tp_clear is only generated for object attributes, and then it includes freeing the object of Py_buffers (so only a Py_buffer attribute doesn't result in a tp_clear function). Finally, tp_dealloc doesn't deallocate buffers either, which it should. So both tp_clear and tp_dealloc should call release buffer (it can be called multiple times on the same buffer). _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
