[Numpy-discussion] subclassing array in c

[Christoph Gohle]

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Hi again,

I don't want to look as if I want other people do my work, so I would like to ask if there is a simple way of tracing memory leaks (without recompiling the python interpreter)?

Cheers,
Christoph
Am 09.03.2012 um 01:22 schrieb Christoph Gohle:

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> Hi
> Am 08.03.2012 um 20:39 schrieb Pauli Virtanen:
> 
>> 08.03.2012 17:37, Christoph Gohle kirjoitti:
>>> thanks for testing. I have now tried on different platforms. I get
>>> all kinds of crashes on os x (now with numpy 1.6.1) and windows
>>> with numpy 1.6.0. On Ubuntu with numpy 1.3.0 I get a hughe memory
>>> leak...
>>> 
>>> Any hints would be welcome.
>> 
>> The type object inherits `tp_alloc` from Numpy. This routine always
>> allocates memory of size NPY_SIZEOF_PYARRAYOBJECT for the
>> PyArrayObject. Therefore, the write to new->unit in your
>> __array_finalize__ goes to unallocated memory.
>> 
>> This is probably a bug in Numpy --- arrayobject.c:array_alloc should
>> respect the size specified by the subtype.
>> 
>> A workaround is probably to specify a suitable tp_alloc routine yourself:
>> 
>>  PyType_GenericAlloc,        /* tp_alloc */
>>   unitArray_new,              /* tp_new */
>>   _PyObject_Del               /* tp_free */
>> 
> OK, I did that. And I get no more segfaults as far as I can tell. But there is still a memory leak:
> 
> In [1]: import spampub
> 
> In [2]: a=[spampub.UnitArray(i,{'s':i}) for i in xrange(100000)]
> 
> In [3]: del a
> 
> after the last two statements, python uses ~60MB more memory than before.
> 
> Thanks for your help
> Christoph
>> -- 
>> Pauli Virtanen
>> 
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> 
> 
> Christoph Gohle
> - --
> Max-Planck-Institut für Quantenoptik
> Abteilung Quantenvielteilchensysteme
> Hans-Kopfermann-Strasse 1
> 85748 Garching
> 
> christoph.gohle at mpq.mpg.de
> tel: +49 89 32905 283
> fax: +49 89 32905 313
> 
> 
> 
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Christoph Gohle
- --
Max-Planck-Institut für Quantenoptik
Abteilung Quantenvielteilchensysteme
Hans-Kopfermann-Strasse 1
85748 Garching

christoph.gohle at mpq.mpg.de
tel: +49 89 32905 283
fax: +49 89 32905 313



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