On Wed, Feb 2, 2022 at 9:25 AM dw-git@d-woods.co.uk wrote:
Guido van Rossum wrote:
My question for you is if you're willing to write up a list of things in CPython that you depend on. Or is this just something you're not willing to commit to? It would be nice to know which it is, just so the CPython team knows what we're up against.
I'm happy to prepare a list of CPython internals that Cython uses. Obviously there's no guarantee that it'll be complete (just because it involves lots of manually finding things in code so is full of human error) or that it doesn't change in future. But a list would at least let everyone know where they stand.
A subset of these issues are listed in these two issues:
* PyThreadState: https://bugs.python.org/issue39947 * PyFrameObject: https://bugs.python.org/issue40421
By the way, I have a pending PR to add PyThreadState_SetTrace(tstate, trace_func) and PyThreadState_SetProfile(tstate, profile_func) to avoid modifying directly PyThreadState members directly: (c_tracefunc and c_traceobj) and (c_profilefunc and c_profileobj). The implementation is more complicated than what you would expect: it does Py_DECREF() which can trigger a GC collection, it requires to call _PyThreadState_ResumeTracing() which is non-trivial, etc. But it's unclear to me if debbugers and profilers *can* or *would like* to use such function which requires to hold the GIL and can execute arbitrary Python code (Py_DECREF which can trigger a GC collection).
=> PR: https://github.com/python/cpython/pull/29121
Victor