On 15.08.2012, 11:05:42 Phil Thompson wrote:
> On Tue, 14 Aug 2012 23:47:51 +0200, mathias.b...@gmx.de wrote:
>> Thanks for the answer. However, it appears I've not made myself
>> clear enough.
>> I don't want the C++ wrapper to be owned by Python; surely, I
>> can achieve that with "sipTransferTo". But nothing is done about the
>> Python part. When I delete the wrapper in C++, the Python part it wraps
>> stays alive, because its reference count is not touched. (No parent!)
>> I have to manually, explicitely decrease the reference count to get
>> rid of it. I'm not complaining. I get this Python object from a Python
>> function, so I have to take care of it.
>>
>> However, the sip module already contains some code that essentially
>> already would do what I want:
>>
>> ======================== siplib.c ===================================
>> void sip_api_common_dtor(sipSimpleWrapper *sipSelf)
>> {
>> if (sipSelf != NULL && sipInterpreter != NULL)
>> {
>> PyObject *xtype, *xvalue, *xtb;
>>
>> SIP_BLOCK_THREADS
>>
>> /* We may be tidying up after an exception so preserve it. */
>> PyErr_Fetch(&xtype, &xvalue, &xtb);
>> callPyDtor(sipSelf);
>> PyErr_Restore(xtype, xvalue, xtb);
>>
>> sipOMRemoveObject(&cppPyMap, sipSelf);
>>
>> /* This no longer points to anything useful. */
>> clear_access_func(sipSelf);
>>
>> /*
>> * If C/C++ has a reference (and therefore no parent) then
> remove
>> it.
>> * Otherwise remove the object from any parent.
>> */
>> if (sipCppHasRef(sipSelf))
>> {
>> sipResetCppHasRef(sipSelf);
>> Py_DECREF(sipSelf);
>> }
>> else if (PyObject_TypeCheck((PyObject *)sipSelf, (PyTypeObject
>> *)&sipWrapper_Type))
>> removeFromParent((sipWrapper *)sipSelf);
>>
>> SIP_UNBLOCK_THREADS
>> }
>> }
>> =====================================================================
>>
>> What about:
>>
>> if (sipCppHasRef(sipSelf))
>> {
>> sipResetCppHasRef(sipSelf);
>> Py_DECREF(sipSelf);
>> }
>>
>> Is there an official way for my wrapper to have the "SIP_CPP_HAS_REF"
> flag
>> set?
>> It would then automatically dispose its Python counterpart.
> I could change sipTransferTo() to do this if the owner was Py_None. At the
> moment this is undocumented behaviour. Would this be sufficient?
I believe so.
Best Regards,
Mathias Born
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