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[Python-Dev] RE: [Python-checkins] python/dist/src/Objects typeobject.c, 2.244, 2.245

Guido van Rossum guido at python.org
Fri Oct 24 11:59:04 EDT 2003 
> >   Py_INCREF(Py_True);
> >   return Py_True;
> > 
> > takes less time than
> > 
> >   return PyBool_FromLong(1);
> > 
> > Maybe a pair of macros Py_return_True and Py_return_False would make
> > sense?
> 
> Sorry if this was already suggested and hastily rejected, but why do
> we care at all about the reference counter of the few heavily-used
> immortal objects of CPython?

It was never discussed; I don't recall that it has ever occurred to
me.

> I guess allowing their counter not to be carefully maintained
> ventures to the slippery slopes of bad code.  Anyway, my two cents
> for a (very) slightly faster and shorter code would be to be allowed
> never to do Py_INCREF or Py_DECREF when we know that the object is
> Py_None, Py_False or Py_True.  These three would have a dummy
> tp_dealloc that just resets the reference counter to some large
> value if it ever reaches zero.

I think there are debugging modes where this would upset some counters
that maintain a balance of the total number of references in the
world.

I also don't think that the performance ggain would be measurable.

Maybe the slight code size decrease would have some benefits.

I'm worried that there would be a negative effect in terms of people
copying the pattern for other objects.

--Guido van Rossum (home page: http://www.python.org/~guido/)
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