Re: [RFC][2/5] Event and event registry

[Richard Ward <richard.j.ward1@googlemail.com>]

Tom Tromey wrote:
>>>>>> "Oguz" == Oguz Kayral <oguzkayral@gmail.com> writes:
> Oguz>   Py_INCREF (func);
> Oguz>   PyList_Append (callback_list, func);
> 
> I always forget whether the list APIs incref themselves, or not.

As a general rule, The list/dict/tupe functions do their own 
incrementing (so the Py_INCREF above is not needed).

The main Exceptions are Py(List|Tuple)_SetItem, which steal a reference. 
The idea being if you create a sequence with Py(List|Tuple)_New(length) 
with length>0, you are probably going to create a bunch of objects to 
put in the list. The stealing of references mean you don't have to call 
Py_DECREF after each Py(List|Tuple)_SetItem (but you must own a `spare' 
reference when you do it).

FWIW there seem to be a fair few places in gdb where Py_INCREF is used 
over-zealously. Sometimes this is just extra increments to python's 
None, True and False values, which I suppose won't cause any leaks, but 
there are a few places that will.

Richard.