The `free_work_item()` function in QSBR may call arbitrary code via
Python object destructors, which may reenter the QSBR code. Reorder
the processing of work items to be robust to reentrancy.
Also fix the TODO for the out of memory situation.
Move many functions from _testcapimodule.c into more specific files
in Modules/_testcapi/.
In moved code:
* Replace get_testerror() with PyExc_AssertionError.
* Replace raiseTestError() with
PyErr_Format(PyExc_AssertionError, ...).
This exposes `PyUnstable_Object_ClearWeakRefsNoCallbacks` as an unstable
C-API function to provide a thread-safe mechanism for clearing weakrefs
without executing callbacks.
Some C-API extensions need to clear weakrefs without calling callbacks,
such as after running finalizers like we do in subtype_dealloc.
Previously they could use `_PyWeakref_ClearRef` on each weakref, but
that's not thread-safe in the free-threaded build.
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Add Py_GetConstant() and Py_GetConstantBorrowed() functions.
In the limited C API version 3.13, getting Py_None, Py_False,
Py_True, Py_Ellipsis and Py_NotImplemented singletons is now
implemented as function calls at the stable ABI level to hide
implementation details. Getting these constants still return borrowed
references.
Add _testlimitedcapi/object.c and test_capi/test_object.py to test
Py_GetConstant() and Py_GetConstantBorrowed() functions.
Sam Gross