On Tue, Nov 12, 2019 at 3:11 PM Victor Stinner <vstin...@python.org> wrote: > Are you ok to modify internal C functions to pass explicitly tstate?
I'm also in favor (strongly)! (no surprises there) The only concerns I've heard is that on some platforms there is a measurable overhead once you hit a threshold of a specific small number of parameters. Adding this extra parameter will put some functions over that threshold. I don't have any more information than that. > There are different reasons to pass explicitly tstate, but my main > motivation is to rework Python code base to move away from implicit > global states to states passed explicitly, to implement the PEP 554 > "Multiple Interpreters in the Stdlib". In short, the final goal is to > run multiple isolated Python interpreters in the same process: run > pure Python code on multiple CPUs in parallel with a single process > (whereas multiprocessing runs multiple processes). FTR, PEP 554 is explicitly independent of efforts to stop sharing the GIL between interpreters. I argue there that it is a good idea regardless. The existing functionality the PEP exposes, though, clearly benefits from better isolation between interpreters (including not sharing the GIL). :) On Thu, Nov 14, 2019 at 4:12 AM Victor Stinner <vstin...@python.org> wrote: > Another approach would be to pass a "PyContext*" pointer which > contains tstate, but also additional fields. But I chose to state with > a direct "PyThreadState* tstate" to avoid one indirection to every > tstate access. Currently, tstate seems to be enough for the current > code base. FWIW, I favor this approach as well. As long as it is an opaque type, a PyContext allows us to be more flexible in adapting to the future. For now it could even be a simple alias for PyThreadState. Regardless, I'm not convinced that using a PyContext will have a real impact on runtime performance. Also, we already use "context" in a number of ways in Python. So "PyContext" might not be the best name. It probably needs to be a name without "context" in it or one with a concrete clue (e.g. 'PyRuntimeContext"). Anyway, thanks for driving this discussion, Victor! -eric _______________________________________________ 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/C7EQXGL3RCOLQNBCK7CVRDT52FWJFAVT/ Code of Conduct: http://python.org/psf/codeofconduct/
