[Cython] Cython 0.16

[mark florisson]

On 28 October 2011 21:59, mark florisson <markflorisson88 at gmail.com> wrote:
> On 28 October 2011 21:55, Robert Bradshaw <robertwb at math.washington.edu> wrote:
>> With Mark's fused types and memory views going in, I think it's about
>> time for a new release. Thoughts? Anyone want to volunteer to take up
>> the process?
>>
>> - Robert
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>> cython-devel at python.org
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>>
>
> That'd be cool. However there are a few outstanding issues:
>    a) the compiler is somewhat slower (possible solution: lazy utility codes)
>    b) there's a potential memory leak problem for memoryviews with
> object dtype that contain themselves, this still needs investigation.
>
> As for a), Stefan mentioned code spending a lot of time in sub.
> Stefan, could you post the code for this that made Cython compile very
> slowly?
>

It seems that NumPy does not support cyclic references, it has
'(traverseproc)0,                            /* tp_traverse */' in its
source (PyArray_Type is the ndarray right?). Indeed, this code prints
"deallocated!" only if there is no reference cycle:


import numpy

cdef class DeallocateMe(object):
    def __dealloc__(self):
        print "deallocated!"
a = numpy.arange(20, dtype=numpy.object)
a[10] = DeallocateMe()
a[1] = a # <- try commenting out this line
del a
import gc
gc.collect()

Anyway, I got it to traverse and clear the buffer object and the
memoryview slice struct, so it should work if the buffer exporter
supports cycles.