* Support free-threaded CPython (PEP 703)
Some additional locking is added in the free-threaded build when
`Py_GIL_DISABLED` is defined:
- Most accesses to internals are protected by a single mutex
- The registered_instances uses a striped lock to improve concurrency
Pybind11 modules can indicate support for running with the GIL disabled
by calling `set_gil_not_used()`.
* refactor: use PYBIND11_MODULE (#11)
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
* Address code review
* Suppress MSVC warning
* Changes from review
* style: pre-commit fixes
* `py::mod_gil_not_used()` suggestion.
* Update include/pybind11/pybind11.h
---------
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>
* Fix segfault when reloading interpreter with external modules
When embedding the interpreter and loading external modules in that
embedded interpreter, the external module correctly shares its
internals_ptr with the one in the embedded interpreter. When the
interpreter is shut down, however, only the `internals_ptr` local to
the embedded code is actually reset to nullptr: the external module
remains set.
The result is that loading an external pybind11 module, letting the
interpreter go through a finalize/initialize, then attempting to use
something in the external module fails because this external module is
still trying to use the old (destroyed) internals. This causes
undefined behaviour (typically a segfault).
This commit fixes it by adding a level of indirection in the internals
path, converting the local internals variable to `internals **` instead
of `internals *`. With this change, we can detect a stale internals
pointer and reload the internals pointer (either from a capsule or by
creating a new internals instance).
(No issue number: this was reported on gitter by @henryiii and @aoloe).
