[Cython] cython leaks references to Py_None for cdef'ed globals

[Robert Bradshaw]

On Oct 1, 2008, at 11:19 AM, Lisandro Dalcin wrote:

> BTW, this patch fix the issue by not initializing cdef'ed module
> globals to None. But this is not the safest approach (I can imagine
> some nasty ways to originate segfaults). Perhaps we should try to fix
> the isue in FinalOptimizePhase.visit_SingleAssignmentNode

I agree that this should be fixed (I remember debugging a nasty bug  
where the refcount of the integer 0 wrapped around, ugh..). However,  
FinalOptimizePhase is the right place to do it.

>
> On Wed, Oct 1, 2008 at 3:13 PM, Lisandro Dalcin <dalcinl at gmail.com>  
> wrote:
>> Consider the following code inside a one-line pyx file:
>>
>> cdef object someint = 7
>>
>> Then Cython generates the following inside the module init function:
>>
>>  /*--- Global init code ---*/
>>  __pyx_v_9refleaks2_someint = Py_None; Py_INCREF(Py_None);
>>
>>  /* "/u/dalcinl/Devel/Cython/sandbox/refleaks2.pyx":1
>>  * cdef object someint = 7             # <<<<<<<<<<<<<<
>>  *
>>  */
>>  Py_INCREF(__pyx_int_7);
>>  __pyx_v_9refleaks2_someint = __pyx_int_7;
>>
>>
>> Clearly, Py_None references are being leaked. All this is because of
>> bad interaction between this two methods:
>>
>> * ModuleNode.generate_global_init_code(...) (in ModuleNode.py)
>> * FinalOptimizePhase.visit_SingleAssignmentNode(...) (in Optimize.py)
>>
>>
>>
>> --
>> Lisandro Dalcín
>> ---------------
>> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
>> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
>> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
>> PTLC - Güemes 3450, (3000) Santa Fe, Argentina
>> Tel/Fax: +54-(0)342-451.1594
>>
>
>
>
> -- 
> Lisandro Dalcín
> ---------------
> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
> PTLC - Güemes 3450, (3000) Santa Fe, Argentina
> Tel/Fax: +54-(0) 
> 342-451.1594<fixinitnoneleaks.diff>___________________________________ 
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