Reply to an old thread. On Sat, Oct 31, 2020 at 8:02 AM Nick Coghlan <ncogh...@gmail.com> wrote: > > Debuggers and profilers usually only care of specific frames or > > function calls (ex: 10% of function calls or even a single function > > call in a whole application). The problem is how to make them as > > efficient as possible for "no operation" calls, when they don't care > > about the current frame. Avoiding PyFrame_FastToLocalsWithError() to > > enter the debugger/profile and avoiding PyFrame_LocalsToFast() on exit > > sounds a simple and practical solution. > > Aye, I agree. I just don't think we can remove those implicit calls > without preparing a replacement API first.
Again, I don't think that it's incompatible. We can enforce calling PyFrame_FastToLocalsWithError() at enter and PyFrame_LocalsToFast() at exit for now, and enhance the API later. > Unfortunately, cell variables mean that there's no way to make > snapshot-with-writeback logic consistently correct in the presence of > generators and coroutines (...) I do understand that there are corner cases where it doesn't work, ok. But https://bugs.python.org/issue42197 is a simple and ready to merge solution which should optimize profilers and debuggers for the most common case. To be clear: currently, PyFrame_FastToLocalsWithError() is called at enter and PyFrame_LocalsToFast() is called at exit. So asking debuggers/profilers to call them explicitly doesn't make the situation worse (nor better ;-)) for generators/coroutines, it would be exactly the same behavior. It's just an optimization. The PEP 558 is being discussed for 5 years and still a draft. I don't think that it should hold bpo-42197 optimization. Victor -- Night gathers, and now my watch begins. It shall not end until my death. _______________________________________________ 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/MV2723DT7BLHBJPNM6K4WHLTWSRMHZLN/ Code of Conduct: http://python.org/psf/codeofconduct/
