This backports several PRs for gh-113993, making interned strings mortal so they can be garbage-collected when no longer needed.
* Allow interned strings to be mortal, and fix related issues (GH-120520)
* Add an InternalDocs file describing how interning should work and how to use it.
* Add internal functions to *explicitly* request what kind of interning is done:
- `_PyUnicode_InternMortal`
- `_PyUnicode_InternImmortal`
- `_PyUnicode_InternStatic`
* Switch uses of `PyUnicode_InternInPlace` to those.
* Disallow using `_Py_SetImmortal` on strings directly.
You should use `_PyUnicode_InternImmortal` instead:
- Strings should be interned before immortalization, otherwise you're possibly
interning a immortalizing copy.
- `_Py_SetImmortal` doesn't handle the `SSTATE_INTERNED_MORTAL` to
`SSTATE_INTERNED_IMMORTAL` update, and those flags can't be changed in
backports, as they are now part of public API and version-specific ABI.
* Add private `_only_immortal` argument for `sys.getunicodeinternedsize`, used in refleak test machinery.
Make sure the statically allocated string singletons are unique. This means these sets are now disjoint:
- `_Py_ID`
- `_Py_STR` (including the empty string)
- one-character latin-1 singletons
Now, when you intern a singleton, that exact singleton will be interned.
* Add a `_Py_LATIN1_CHR` macro, use it instead of `_Py_ID`/`_Py_STR` for one-character latin-1 singletons everywhere (including Clinic).
* Intern `_Py_STR` singletons at startup.
* Beef up the tests. Cover internal details (marked with `@cpython_only`).
* Add lots of assertions
* Don't immortalize in PyUnicode_InternInPlace; keep immortalizing in other API (GH-121364)
* Switch PyUnicode_InternInPlace to _PyUnicode_InternMortal, clarify docs
* Document immortality in some functions that take `const char *`
This is PyUnicode_InternFromString;
PyDict_SetItemString, PyObject_SetAttrString;
PyObject_DelAttrString; PyUnicode_InternFromString;
and the PyModule_Add convenience functions.
Always point out a non-immortalizing alternative.
* Don't immortalize user-provided attr names in _ctypes
* Immortalize names in code objects to avoid crash (GH-121903)
* Intern latin-1 one-byte strings at startup (GH-122303)
There are some 3.12-specific changes, mainly to allow statically allocated strings in deepfreeze. (In 3.13, deepfreeze switched to the general `_Py_ID`/`_Py_STR`.)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
The tests were only checking cases where the slot wrapper was present in the initial case. They were missing when the slot wrapper was added in the additional initializations. This fixes that.
(cherry-picked from commit 490e0ad83a, AKA gh-122248)
In gh-121602, I applied a fix to a builtin types initialization bug.
That fix made sense in the context of some broader future changes,
but introduced a little bit of extra complexity. For earlier versions
those future changes are not relevant; we can avoid the extra complexity.
Thus we can revert that earlier change and replace it with this one,
which is more focused and conceptually simpler. This is essentially
the implementation of an idea that @markshannon pointed out to me.
Note that this change would be much smaller if we didn't have to deal
with repr compatibility for builtin types that explicitly inherit tp slots
(see expect_manually_inherited()). The alternative is to stop
*explicitly* inheriting tp slots in static PyTypeObject values,
which is churn that we can do separately.
(cherry picked from commit 716c6771fc, AKA gh-121932)
When builtin static types are initialized for a subinterpreter, various "tp" slots have already been inherited (for the main interpreter). This was interfering with the logic in add_operators() (in Objects/typeobject.c), causing a wrapper to get created when it shouldn't. This change fixes that by preserving the original data from the static type struct and checking that.
(cherry picked from commit 5250a03133, AKA gh-121602)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
gh-112266: Remove `(if defined)` part from `__dict__` and `__weakref__` docstrings (GH-112268)
(cherry picked from commit f8129146ef)
Co-authored-by: Nikita Sobolev <mail@sobolevn.me>
gh-106719: Fix __annotations__ getter and setter in the type and module types (GH-106720)
No longer suppress arbitrary errors. Simplify the code.
(cherry picked from commit e1c295e3da)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
gh-105227: Add PyType_GetDict() (GH-105747)
This compensates for static builtin types having `tp_dict` set to `NULL`.
(cherry picked from commit a840806d33)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
Co-authored-by: Petr Viktorin <encukou@gmail.com>
[3.12] gh-106033: Get rid of new occurrences of PyDict_GetItem and PyObject_HasAttr (GH-106034)
These functions are broken by design because they discard any exceptions raised
inside, including MemoryError and KeyboardInterrupt. They should not be
used in new code.
(cherry picked from commit 1d33d53780)
When I added the relevant condition to type_ready_set_bases() in gh-103912, I had missed that the function also sets tp_base and ob_type (if necessary). That led to problems for third-party static types.
We fix that here, by making those extra operations distinct and by adjusting the condition to be more specific.
(cherry picked from commit 1469393)
Co-authored-by: Eric Snow ericsnowcurrently@gmail.com
In gh-103912 we added tp_bases and tp_mro to each PyInterpreterState.types.builtins entry. However, doing so ignored the fact that both PyTypeObject fields are public API, and not documented as internal (as opposed to tp_subclasses). We address that here by reverting back to shared objects, making them immortal in the process.
(cherry picked from commit 7be667d)
Co-authored-by: Eric Snow ericsnowcurrently@gmail.com
This implements PEP 695, Type Parameter Syntax. It adds support for:
- Generic functions (def func[T](): ...)
- Generic classes (class X[T](): ...)
- Type aliases (type X = ...)
- New scoping when the new syntax is used within a class body
- Compiler and interpreter changes to support the new syntax and scoping rules
Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Co-authored-by: Eric Traut <eric@traut.com>
Co-authored-by: Larry Hastings <larry@hastings.org>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
his involves moving tp_dict, tp_bases, and tp_mro to PyInterpreterState, in the same way we did for tp_subclasses. Those three fields are effectively const for builtin static types (unlike tp_subclasses). In theory we only need to make their values immortal, along with their contents. However, that isn't such a simple proposition. (See gh-103823.) In the meantime the simplest solution is to move the fields into the interpreter.
One alternative is to statically allocate the values, but that's its own can of worms.
Core static types will continue to use the global value. All other types
will use the per-interpreter value. They all share the same range, where
the global types use values < 2^16 and each interpreter uses values
higher than that.
This speeds up `super()` (by around 85%, for a simple one-level
`super().meth()` microbenchmark) by avoiding allocation of a new
single-use `super()` object on each use.
This is the implementation of PEP683
Motivation:
The PR introduces the ability to immortalize instances in CPython which bypasses reference counting. Tagging objects as immortal allows up to skip certain operations when we know that the object will be around for the entire execution of the runtime.
Note that this by itself will bring a performance regression to the runtime due to the extra reference count checks. However, this brings the ability of having truly immutable objects that are useful in other contexts such as immutable data sharing between sub-interpreters.
* Eliminate all remaining uses of Py_SIZE and Py_SET_SIZE on PyLongObject, adding asserts.
* Change layout of size/sign bits in longobject to support future addition of immortal ints and tagged medium ints.
* Add functions to hide some internals of long object, and for setting sign and digit count.
* Replace uses of IS_MEDIUM_VALUE macro with _PyLong_IsCompact().
Moving it valuable with a per-interpreter GIL. However, it is also useful without one, since it allows us to identify refleaks within a single interpreter or where references are escaping an interpreter. This becomes more important as we move the obmalloc state to PyInterpreterState.
https://github.com/python/cpython/issues/102304
When __getattr__ is defined, python with try to find an attribute using _PyObject_GenericGetAttrWithDict
find nothing is reasonable so we don't need an exception, it will hurt performance.
