Sebastian Haase wrote:
Hi,
I'm converting SWIG typemap'ed C extensions from numarray to numpy.
I studied (and use parts of) numpy.i from the doc directory.
I noticed that there is no
decref for the TYPEMAP_INPLACE2 typemap. This uses a function
obj_to_array_no_conversion() which in turn just returns
the original PyObject* ( casted to a PyArrayObject* after some sanity
checks) It looks to me that in this case there should be an explicit
Py_INCREF() - in case the function is threaded (releases the Python
GIL) since it holds a pointer to that object's data .
Probably, true. The numpy.i typemaps are not thoroughly reference-count
checked.
(Alternatively) Travis suggested (at the
http://www.scipy.org/Converting_from_numarray wiki page) using
PyArray_FromAny - is this incrementing the ref.count (implicitely) ?
The numarray equivalent (NA_InputArray) IS incrementing the ref.count
(as far as I know...).
Yes, you get back a new reference from PyArray_FromAny.
Furthermore on that same wiki page the PyArray_FromAny() is called
together with PyArray_DescrFromType(type).
After searching through the numpy source I found that in
blasdot/_dotblas.c (in dotblas_matrixproduct() )there is an explicit
Py_INCREF even on the dtype returned from PyArray_DescrFromType.
PyArray_FromAny consumes a reference to the PyArray_Descr * object
(which is a Python object). Thus, because PyArray_FromAny is called
twice with the same data-type object, there is a need to increment it's
reference count.
-Travis
-
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV
___
Numpy-discussion mailing list
Numpy-discussion@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/numpy-discussion
