This PR adds the ability to enable the GIL if it was disabled at
interpreter startup, and modifies the multi-phase module initialization
path to enable the GIL when loading a module, unless that module's spec
includes a slot indicating it can run safely without the GIL.
PEP 703 called the constant for the slot `Py_mod_gil_not_used`; I went
with `Py_MOD_GIL_NOT_USED` for consistency with gh-104148.
A warning will be issued up to once per interpreter for the first
GIL-using module that is loaded. If `-v` is given, a shorter message
will be printed to stderr every time a GIL-using module is loaded
(including the first one that issues a warning).
Remove the "cpython/pytime.h" header file: it only contained private
functions. Move functions to the internal pycore_time.h header file.
Move tests from _testcapi to _testinternalcapi. Rename also test
methods to have the same name than tested C functions.
No longer export these functions:
* _PyTime_Add()
* _PyTime_As100Nanoseconds()
* _PyTime_FromMicrosecondsClamp()
* _PyTime_FromTimespec()
* _PyTime_FromTimeval()
* _PyTime_GetPerfCounterWithInfo()
* _PyTime_MulDiv()
This is related to fixing the refleaks introduced by commit 096d009. I haven't been able to find the leak yet, but these changes are a consequence of that effort. This includes some cleanup, some tweaks to the existing tests, and a bunch of new test cases. The only change here that might have impact outside the tests in question is in imp.py, where I update imp.load_dynamic() to use spec_from_file_location() instead of creating a ModuleSpec directly.
Also note that I've updated the tests to only skip if we're checking for refleaks (regrtest's --huntrleaks), whereas in gh-101969 I had skipped the tests entirely. The tests will be useful for some upcoming work and I'd rather the refleaks not hold that up. (It isn't clear how quickly we'll be able to fix the leaking code, though it will certainly be done in the short term.)
https://github.com/python/cpython/issues/102251
The new test exercises the most important variants for single-phase init extension modules. We also add some explanation about those variants to import.c.
https://github.com/python/cpython/issues/101758
This makes it more clear that a given test is definitely testing against a single-phase init (legacy) extension module. The new module is a companion to _testmultiphase.
https://github.com/python/cpython/issues/98627