This is a temporary commit to verify that the unbuffered stdout fix
makes the hanging test visible in CI logs. REVERT THIS COMMIT after
confirming the output appears.
This test verifies that gil_safe_call_once_and_store provides separate
storage for each interpreter when subinterpreter support is enabled.
The test caches the interpreter ID in the main interpreter, then creates
a subinterpreter and verifies it gets its own cached value (not the main
interpreter's). Without per-interpreter storage, the subinterpreter would
incorrectly see the main interpreter's cached object.
This test hangs in Py_EndInterpreter() when the subinterpreter is
destroyed from a different thread than it was created on.
The hang was observed:
- Intermittently on macOS with Python 3.14.0t
- Predictably on macOS, Ubuntu, and Windows with Python 3.14.1t and 3.14.2t
Root cause analysis points to an interaction between pybind11's
subinterpreter creation code and CPython's free-threaded runtime,
specifically around PyThreadState_Swap() after PyThreadState_DeleteCurrent().
See detailed analysis: https://github.com/pybind/pybind11/pull/5933
* Avoid heap allocation for function calls with a small number of arguments
We don't have access to llvm::SmallVector or similar, but given the
limited subset of the `std::vector` API that
`function_call::args{,_convert}` need and the "reserve-then-fill"
usage pattern, it is relatively straightforward to implement custom
containers that get the job done.
Seems to improves time to call the collatz function in
pybind/pybind11_benchmark significantly; numbers are a little noisy
but there's a clear improvement from "about 60 ns per call" to "about
45 ns per call" on my machine (M4 Max Mac), as measured with
`timeit.repeat('collatz(4)', 'from pybind11_benchmark import
collatz')`.
* clang-tidy
* more clang-tidy
* clang-tidy NOLINTBEGIN/END instead of NOLINTNEXTLINE
* forgot to increase inline size after removing std::variant
* constexpr arg_vector_small_size, use move instead of swap to hopefully clarify second_pass_convert
* rename test_embed to test_low_level
* rename test_low_level to test_with_catch
* Be careful to NOINLINE slow paths
* rename array/vector members to iarray/hvector. Move comment per request. Add static_asserts for our untagged union implementation per request.
* drop is_standard_layout assertions; see https://github.com/pybind/pybind11/pull/5824#issuecomment-3308616072
