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Helpers for getting references to singletons #91927
Description
Activity
The problem of adding
Py_RefNone()is that it grows up the Python C API by 1 more function which should be:- tested
- documented
- new comers have to learn about it
If we consider 5 singletons, we're talking about adding 5 functions. The problem is that the Python C API is already very big and is painful to maintain: see statistics on the C API.
IMO
Py_NewRef(Py_None)is short and it doesn't require to learn a new API but combine two well defined API:Py_None: borrowed reference to theNonesingletonPy_NewRef(): create a new strong reference
See issue #99300 which replaces Py_INCREF() with Py_NewRef(). You can see there that Py_NewRef() is applicable to many cases.
@erlend-aasland: I propose closing this issue in favor of using
Py_NewRef(Py_None).For example, the
Py_RETURN_NONEis now simply defined asreturn Py_NewRef(Py_None).Reacted by Erlend E. Aasland
Feature or enhancement
There are lots of places where a new reference to a singleton is needed. This is done in a variety of ways:
The proposal is to add another way that can hopefully become idiomatic:
The following singletons are considered:
NoneNotImplementedEllipsisFalseTrueIn the internal API, helpers for the following singletons can be added:
_Py_IDand_Py_STRPitch
One advantage of using the new helpers is that it abstracts away the necessity to increment the reference count if immortal instances are implemented.
Alternatively, if immortal instances aren't implemented and all singletons are made per-interpreter, it will slightly reduce the performance overhead by making sure that the singletons are only looked up once (compared to patterns 3, 4, and 5, where the singletons are obtained twice).
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