_PyWeakref_ClearRef was previously exposed in the public C-API, although
it begins with an underscore and is not documented. It's used by a few
C-API extensions. There is currently no alternative public API that can
replace its use.
_PyWeakref_ClearWeakRefsExceptCallbacks is the only thread-safe way to
use _PyWeakref_ClearRef in the free-threaded build. This exposes the C
symbol, but does not make the API public.
* shm_unlink() parameter becomes positional-only.
* shm_open() first parameter (path) becomes positional-only,
the two following parameters remain positional-or-keyword.
Using `race:` filters out warnings if the function appears anywhere in
the stack trace. This can hide a lot of unrelated warnings, especially
for a function like `_PyEval_EvalFrameDefault`, which is somewhere on
the stack more often than not.
Change all free-threaded suppressions to `race_top:`, which only matches
the top frame, and add any new suppressions this exposes.
Some embedders and extensions include parts of the internal API. The
pycore_mimalloc.h file is transitively include by a number of other
internal headers. This avoids include errors for code that was
already including those headers.
The `list_preallocate_exact` function did not zero initialize array
contents. In the free-threaded build, this could expose uninitialized
memory to concurrent readers between the call to
`list_preallocate_exact` and the filling of the array contents with
items.
Use relaxed atomics when reading / writing to the field. There are still a
few places in the GC where we do not use atomics. Those should be safe as
the world is stopped.
A new `compute_powers()` function computes all and only the powers of the base the various base-conversion functions need, as efficiently as reasonably possible (turns out that invoking `**`is needed at most once). This typically gives a few % speedup, but the primary point is to simplify the base-conversion functions, which no longer need their own, ad hoc, and less efficient power-caching schemes.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Make a rough editorial pass over Python 3.13's What's New document. Add the
release highlights, remove or merge some duplicated entries, and reorder
some of the sections (removals should really go before future deprecations).
