## Summary
- Move the `runtime->initialized = 1` store from before `site.py` import to the end of `init_interp_main()`, so `Py_IsInitialized()` only returns true after initialization has fully completed
- Access `initialized` and `core_initialized` through new inline accessors using acquire/release atomics, to also protect from data race undefined behavior
- `PySys_AddAuditHook()` now uses the accessor, so with the flag move it correctly skips audit hook invocation during all init phases (matching the documented "after runtime initialization" behavior) ... We could argue that running these earlier would be good even if the intent was never explicitly expressed, but that'd be its own issue.
## Motivation
`Py_IsInitialized()` returned 1 while `Py_InitializeEx()` was still running — specifically, before `site.py` had been imported. See https://github.com/PyO3/pyo3/issues/5900 where a second thread could acquire the GIL and start executing Python with an incomplete `sys.path` because `site.py` hadn't finished.
The flag was also a plain `int` with no atomic operations, making concurrent reads a C-standard data race, though unlikely to manifest.
## Regression test:
The added test properly fails on `main` with `ERROR: Py_IsInitialized() was true during site import`.
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Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* Drop DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754 macro.
* Use DOUBLE_IS_BIG/LITTLE_ENDIAN_IEEE754 to detect endianness of
float/doubles.
* Drop "unknown_format" code path in PyFloat_Pack/Unpack*().
Co-authored-by: Victor Stinner <vstinner@python.org>
This undoes a change made as a part of PR 137470, for compatibility with EMSDK
4.0.19. It adds `emscripten_trampoline` field in `pycore_runtime_structs.h`
and initializes it from JS initialization code with the wasm-gc based trampoline
if possible. Otherwise we fall back to the JS trampoline.
The pymalloc huge page support had two problems. First, on
architectures where the default huge page size exceeds the arena
size (e.g. 32 MiB on PPC, 512 MiB on ARM64 with 64 KB base
pages), mmap with MAP_HUGETLB silently allocates a full huge page
even when the requested size is smaller. The subsequent munmap
with the original arena size then fails with EINVAL, permanently
leaking the entire huge page. Second, huge pages were always
attempted when compiled in, with no way to disable them at
runtime. On Linux, if the huge page pool is exhausted, page
faults including copy-on-write faults after fork deliver SIGBUS
and kill the process.
The arena allocator now queries the system huge page size from
/proc/meminfo and skips MAP_HUGETLB when the arena size is not a
multiple of it. Huge pages also now require explicit opt-in at
runtime via the PYTHON_PYMALLOC_HUGEPAGES environment variable,
which is read through PyConfig and respects -E and -I flags.
The config field pymalloc_hugepages is propagated to the runtime
allocators struct so the low-level arena allocator can check it
without calling getenv directly.
With https://github.com/llvm/llvm-project/pull/150201 being merged, there is
now a better way to generate the Emscripten trampoline, instead of including
hand-generated binary WASM content. Requires Emscripten 4.0.12.
Switches over to a _Py_thread_local in place of autoTssKey, and also fixes a few other checks regarding PyGILState_Ensure after finalization.
Note that this doesn't fix concurrent use of PyGILState_Ensure with Py_Finalize; I'm pretty sure zapthreads doesn't work at all, and that needs to be fixed seperately.
Move pycore_obmalloc.h include from pycore_interp_structs.h to
pycore_runtime_structs.h.
Add also comment explaining the purpose of each include in
pycore_interp_structs.h, pycore_runtime_structs.h and
pycore_structs.h.
Remove <stdbool.h> and <stddef.h> from pycore_structs.h.
