cpython/Include
mpage e99f159be4
gh-115999: Stop the world when invalidating function versions (#124997)
Stop the world when invalidating function versions

The tier1 interpreter specializes `CALL` instructions based on the values
of certain function attributes (e.g. `__code__`, `__defaults__`). The tier1
interpreter uses function versions to verify that the attributes of a function
during execution of a specialization match those seen during specialization.
A function's version is initialized in `MAKE_FUNCTION` and is invalidated when
any of the critical function attributes are changed. The tier1 interpreter stores
the function version in the inline cache during specialization. A guard is used by
the specialized instruction to verify that the version of the function on the operand
stack matches the cached version (and therefore has all of the expected attributes).
It is assumed that once the guard passes, all attributes will remain unchanged
while executing the rest of the specialized instruction.

Stopping the world when invalidating function versions ensures that all critical
function attributes will remain unchanged after the function version guard passes
in free-threaded builds. It's important to note that this is only true if the remainder
of the specialized instruction does not enter and exit a stop-the-world point.

We will stop the world the first time any of the following function attributes
are mutated:

- defaults
- vectorcall
- kwdefaults
- closure
- code

This should happen rarely and only happens once per function, so the performance
impact on majority of code should be minimal.

Additionally, refactor the API for manipulating function versions to more clearly
match the stated semantics.
2024-10-08 10:04:35 -04:00
..
cpython gh-111178: Fix function signatures in longobject.c (#124895) 2024-10-02 17:41:19 +02:00
internal gh-115999: Stop the world when invalidating function versions (#124997) 2024-10-08 10:04:35 -04:00
abstract.h gh-105201: Add PyIter_NextItem() (#122331) 2024-08-08 00:47:15 +02:00
bltinmodule.h these builtins have to be initialized 2009-05-09 18:10:51 +00:00
boolobject.h gh-115754: Add Py_GetConstant() function (#116883) 2024-03-21 16:07:00 +00:00
bytearrayobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
bytesobject.h gh-108765: Move standard includes to Python.h (#108769) 2023-09-01 21:03:20 +02:00
ceval.h GH-120507: Lower the BEFORE_WITH and BEFORE_ASYNC_WITH instructions. (#120640) 2024-06-18 12:17:46 +01:00
codecs.h Remove private _PyCodec_Lookup() function (#106269) 2023-06-30 09:34:01 +00:00
compile.h gh-109596: Ensure repeated rules in the grammar are not allowed and fix incorrect soft keywords (#109606) 2023-09-22 19:03:23 +01:00
complexobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
critical_section.h gh-119344: Make critical section API public (#119353) 2024-06-21 15:50:18 -04:00
datetime.h gh-87347: Add parenthesis around macro arguments (#93915) 2022-06-20 16:04:52 +02:00
descrobject.h gh-103509: PEP 697 -- Limited C API for Extending Opaque Types (GH-103511) 2023-05-04 09:56:53 +02:00
dictobject.h gh-106004: PyDict_GetItemRef() should only be in the limited API 3.13 (GH-107229) 2023-07-25 21:48:07 +03:00
dynamic_annotations.h gh-96959: Update HTTP links which are redirected to HTTPS (GH-96961) 2022-09-24 14:38:53 +03:00
enumobject.h Implement and apply PEP 322, reverse iteration 2003-11-06 14:06:48 +00:00
errcode.h gh-107450: Check for overflow in the tokenizer and fix overflow test (#110832) 2023-10-16 16:42:49 +02:00
exports.h gh-121040: Use __attribute__((fallthrough)) (#121044) 2024-06-27 09:58:44 +00:00
fileobject.h gh-106320: Remove _PyIsSelectable_fd() C API (#107142) 2023-07-23 19:07:12 +00:00
fileutils.h gh-108765: Move stat() fiddling from pyport.h to fileutils.h (#108854) 2023-09-03 21:32:13 +00:00
floatobject.h gh-121905: Consistently use "floating-point" instead of "floating point" (GH-121907) 2024-07-19 08:06:02 +00:00
frameobject.h bpo-45434: Remove useless space in includes (GH-28963) 2021-10-15 01:50:04 +02:00
genericaliasobject.h bpo-44654: Refactor and clean up the union type implementation (GH-27196) 2021-07-17 22:44:10 +03:00
import.h gh-105922: Add PyImport_AddModuleRef() function (#105923) 2023-06-20 08:48:14 +02:00
intrcheck.h gh-106320: Remove private _PyOS_IsMainThread() function (#108605) 2023-08-29 03:20:31 +00:00
iterobject.h gh-106320: Remove _PyAnextAwaitable_Type from the public C API (#108597) 2023-08-29 02:05:11 +00:00
listobject.h gh-114329: Fix PyList_GetItemRef() limited C API definition (#117520) 2024-04-03 21:02:42 +00:00
lock.h gh-117511: Make PyMutex public in the non-limited API (#117731) 2024-06-20 11:29:08 -04:00
longobject.h gh-120389: Add PyLong_FromInt64() and PyLong_AsInt64() (#120390) 2024-08-28 10:16:13 +00:00
marshal.h bpo-45474: Exclude all of marshal.h if Py_LIMITED_API is defined (GH-29061) 2021-10-20 02:32:14 -07:00
memoryobject.h gh-79315: Add Include/cpython/memoryobject.h header (#99723) 2022-11-23 15:44:42 +01:00
methodobject.h gh-114626: Add again _PyCFunctionFastWithKeywords name (GH-115561) 2024-02-19 13:20:46 +01:00
modsupport.h gh-112136: Restore removed _PyArg_Parser (#121262) 2024-07-03 18:36:57 +02:00
moduleobject.h gh-116322: Rename PyModule_ExperimentalSetGIL to PyUnstable_Module_SetGIL (GH-118645) 2024-05-06 18:59:36 +02:00
monitoring.h gh-111997: C-API for signalling monitoring events (#116413) 2024-05-04 08:23:50 +00:00
object.h gh-124609: Fix _Py_ThreadId for Windows builds using MinGW (#124663) 2024-09-27 18:52:23 +00:00
objimpl.h gh-102013: Move PyUnstable_GC_VisitObjects() to Include/cpython/objimpl.h (#115560) 2024-02-16 15:49:13 +01:00
opcode.h gh-105481: opcode.h is no longer generated during the build (#108080) 2023-08-17 17:07:58 +01:00
opcode_ids.h GH-119866: Spill the stack around escaping calls. (GH-124392) 2024-10-07 14:56:39 +01:00
osdefs.h gh-108765: Reformat Include/osdefs.h (#108766) 2023-09-01 14:35:39 +00:00
osmodule.h Issue #29058: All stable API extensions added after Python 3.2 are now 2016-12-27 14:57:39 +02:00
patchlevel.h Python 3.14.0a0 2024-05-08 16:57:05 +02:00
py_curses.h gh-123961: Add a global state to _curses (#124729) 2024-09-29 15:17:20 +00:00
pyatomic.h gh-108724: Add PyMutex and _PyParkingLot APIs (gh-109344) 2023-09-19 09:54:29 -06:00
pybuffer.h gh-102500: Implement PEP 688 (#102521) 2023-05-04 07:59:46 -07:00
pycapsule.h gh-108240: Add pycore_capsule.h internal header file (#108596) 2023-08-29 01:20:02 +00:00
pydtrace.d bpo-36842: Implement PEP 578 (GH-12613) 2019-05-23 08:45:22 -07:00
pydtrace.h Fix pydtrace.d path comment in Include/pydtrace.h (#28539) 2022-12-31 22:40:25 +05:30
pyerrors.h gh-119521: Rename IncompleteInputError to _IncompleteInputError and remove from public API/ABI (GH-119680) 2024-06-24 14:08:12 +02:00
pyexpat.h gh-115398: Revert PyExpat_CAPI_MAGIC version bump (GH-116411) 2024-03-06 09:55:07 -08:00
pyframe.h gh-93937, C API: Move PyFrame_GetBack() to Python.h (#93938) 2022-06-19 12:02:33 +02:00
pyhash.h gh-111545: Add Include/cpython/pyhash.h header file (#112063) 2023-11-15 01:19:20 +01:00
pylifecycle.h gh-117987: Restore several functions removed in Python 3.13 alpha 1 (GH-117993) 2024-04-18 15:20:38 +02:00
pymacconfig.h gh-110820: Make sure processor specific defines are correct for Universal 2 build on macOS (#112828) 2023-12-08 10:09:34 +01:00
pymacro.h gh-118124: fix assert related C++ checks on Solaris/Illumos (#121974) 2024-07-21 18:50:14 +02:00
pymath.h gh-119613: Soft deprecate Py_IS_NAN/INFINITY/FINITE (#119701) 2024-05-29 10:45:14 +00:00
pymem.h gh-85283: Add PyMem_RawMalloc() to the limited C API (#108570) 2023-10-17 02:41:51 +02:00
pyport.h gh-121040: Use __attribute__((fallthrough)) (#121044) 2024-06-27 09:58:44 +00:00
pystate.h gh-108867: Add PyThreadState_GetUnchecked() function (#108870) 2023-10-03 16:53:51 +00:00
pystats.h GH-124284: Add stats for refcount operations on immortal objects (GH-124288) 2024-09-23 19:10:55 +01:00
pystrcmp.h Merged revisions 59541-59561 via svnmerge from 2007-12-19 02:07:34 +00:00
pystrtod.h gh-106320: Remove private float C API functions (#108430) 2023-08-24 19:09:49 +02:00
Python.h gh-124609: Fix _Py_ThreadId for Windows builds using MinGW (#124663) 2024-09-27 18:52:23 +00:00
pythonrun.h gh-102755: PyErr_DisplayException only in ABI >= 3.12. Tests cover PyErr_Display as well (GH-102849) 2023-03-21 10:36:18 +01:00
pythread.h gh-87135: Hang non-main threads that attempt to acquire the GIL during finalization (GH-105805) 2024-10-02 09:17:49 -07:00
pytypedefs.h bpo-45459: Fix PyModuleDef_Slot type in the limited C API (GH-31668) 2022-03-03 23:06:55 +01:00
rangeobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
README.rst gh-101101: Unstable C API tier (PEP 689) (GH-101102) 2023-02-28 09:31:01 +01:00
refcount.h gh-124127: Make Py_REFCNT() opaque in limited C API 3.14 (#124128) 2024-09-24 08:42:58 +02:00
setobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
sliceobject.h gh-115754: Add Py_GetConstant() function (#116883) 2024-03-21 16:07:00 +00:00
structmember.h Fix typos in comments (#120188) 2024-06-07 10:19:41 +02:00
structseq.h gh-106168: PyTuple_SET_ITEM() now checks the index (#106164) 2023-06-28 03:45:57 +02:00
sysmodule.h gh-117987: Restore several functions removed in Python 3.13 alpha 1 (GH-117993) 2024-04-18 15:20:38 +02:00
traceback.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
tupleobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
typeslots.h gh-124153: Implement PyType_GetBaseByToken() and Py_tp_token slot (GH-124163) 2024-09-18 09:18:19 +02:00
unicodeobject.h gh-124502: Add PyUnicode_Equal() function (#124504) 2024-10-07 21:24:53 +00:00
warnings.h bpo-35134: Split warnings.h and weakrefobject.h (GH-29042) 2021-10-19 01:31:57 +02:00
weakrefobject.h gh-105927: Limit PyWeakref_GetRef() to limited C API 3.13 (#117091) 2024-03-20 23:52:23 +01:00

The Python C API
================

The C API is divided into these sections:

1. ``Include/``: Limited API
2. ``Include/cpython/``: CPython implementation details
3. ``Include/cpython/``, names with the ``PyUnstable_`` prefix: API that can
   change between minor releases
4. ``Include/internal/``, and any name with ``_`` prefix: The internal API

Information on changing the C API is available `in the developer guide`_

.. _in the developer guide: https://devguide.python.org/c-api/