Hi Gabriele, I think the code is currently the only documentation, since this is considered a CPython internal issue. I'm CC'ing Mark Shannon, since he designed this for 3.11.
For a bit of background, see this issue in the Faster CPython tracker: https://github.com/faster-cpython/ideas/issues/31 -- maybe this will help you understand the background (though what was implemented doesn't match the discussion there precisely). Since you seem to be the author of Austin, a sampling profiler for Python code (which I presume itself is written in C or C++), I'm guessing you're asking because you're looking to make Austin work with 3.11. (Actually, the CFrame structure appears in 3.10, but it's not usable for unwinding stack frames in 3.10, since the 3.10 version doesn't have a pointer to the interpreter frame -- it's only used to speed up access to the `use-tracing` flag. So I'm assuming you're asking about 3.10.) One of the goals for the Faster CPython project that has only become in focus for the team recently is helping tools like Austin (and others like Cython, PyDev and Greenlets) that use internal interpreter state figure out how to get their code working in 3.11, without making too many commitments to stable APIs -- we're already thinking about more performance improvements in 3.12 and beyond, which most likely will require us to change the internal data structures again. (We do commit to leaving these internal data structures unchanged for bugfix release cycles, so that once you've got it working for 3.11.0, it should work without changes for 3.11.1, 3.11.2, etc. In fact we hope to stabilize everything starting with the release of 3.11b1, May 2020.) Oh, I see that Brandt has already given a better overview of how this stuff actually works (he's a faster typist than me :-), so I'll just sign off here. If you have more specific questions, you can continue this thread, or you can create a new Discussion item in the https://github.com/faster-cpython/ideas repo. --Guido On Mon, Dec 20, 2021 at 10:25 AM Gabriele <phoenix1...@gmail.com> wrote: > Hi there > > I hope you would indulge me in asking for some details about the new > CFrame structure, even in the form of existing literature (e.g. PEP) > where the idea behind it is explained. > > Also, I'd like to a quick question, if I may. There now appear to be > two ways of unwinding the frame stack: either iterate over > CFrame.previous, or the more traditional PyFrameObject.f_back. I > suspect there are reasons why these are perhaps not actually > equivalent, and indeed this is mainly what I'd like to read in the > literature I've requested above. > > Cheers, > Gabriele > > -- > "Egli è scritto in lingua matematica, e i caratteri son triangoli, > cerchi, ed altre figure > geometriche, senza i quali mezzi è impossibile a intenderne umanamente > parola; > senza questi è un aggirarsi vanamente per un oscuro laberinto." > > -- G. Galilei, Il saggiatore. > _______________________________________________ > Python-Dev mailing list -- python-dev@python.org > To unsubscribe send an email to python-dev-le...@python.org > https://mail.python.org/mailman3/lists/python-dev.python.org/ > Message archived at > https://mail.python.org/archives/list/python-dev@python.org/message/KQOQTLR5IXMJXYZGPDHWR32I2Z53UVBL/ > Code of Conduct: http://python.org/psf/codeofconduct/ > -- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* <http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/>
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