cpython/Include
Sam Gross 052cb717f5
gh-124878: Fix race conditions during interpreter finalization (#130649)
The PyThreadState field gains a reference count field to avoid
issues with PyThreadState being a dangling pointer to freed memory.
The refcount starts with a value of two: one reference is owned by the
interpreter's linked list of thread states and one reference is owned by
the OS thread. The reference count is decremented when the thread state
is removed from the interpreter's linked list and before the OS thread
calls `PyThread_hang_thread()`. The thread that decrements it to zero
frees the `PyThreadState` memory.

The `holds_gil` field is moved out of the `_status` bit field, to avoid
a data race where on thread calls `PyThreadState_Clear()`, modifying the
`_status` bit field while the OS thread reads `holds_gil` when
attempting to acquire the GIL.

The `PyThreadState.state` field now has `_Py_THREAD_SHUTTING_DOWN` as a
possible value. This corresponds to the `_PyThreadState_MustExit()`
check. This avoids race conditions in the free threading build when
checking `_PyThreadState_MustExit()`.
2025-03-06 10:38:34 -05:00
..
cpython gh-124878: Fix race conditions during interpreter finalization (#130649) 2025-03-06 10:38:34 -05:00
internal gh-124878: Fix race conditions during interpreter finalization (#130649) 2025-03-06 10:38:34 -05:00
abstract.h gh-91417: Remove PySequence_Fast() from the limited C API (#129398) 2025-02-02 23:17:30 +01:00
audit.h gh-125604: Move _Py_AuditHookEntry, etc. Out of pycore_runtime.h (gh-125605) 2024-10-18 09:26:08 -06:00
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-120026: soft deprecate Py_HUGE_VAL macro (#120027) 2024-11-01 22:04:31 +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 gh-125063: marshal: Add version 5, improve documentation (GH-126829) 2024-11-15 13:48:57 +01:00
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-129666: Add C11/C++11 to docs and -pedantic-errors to GCC/clang test_c[pp]ext tests (GH-130692) 2025-03-04 14:10:09 +01:00
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-100239: replace BINARY_SUBSCR & family by BINARY_OP with oparg NB_SUBSCR (#129700) 2025-02-07 22:39:54 +00:00
opcode_ids.h gh-130574: renumber RESUME opcode from 149 to 128 (GH-130685) 2025-03-06 08:59:36 +00:00
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 Post 3.14.0a5 2025-02-11 21:26:52 +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-128629: Add Py_PACK_VERSION and Py_PACK_FULL_VERSION (GH-128630) 2025-01-09 11:10:28 +01:00
pymath.h gh-120026: soft deprecate Py_HUGE_VAL macro (#120027) 2024-11-01 22:04:31 +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-128902: Fix check for fallthrough attribute support (#128903) 2025-01-22 04:25:30 -05:00
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-127271: Replace use of PyCell_GET/SET (gh-127272) 2024-12-03 10:33:06 -08:00
pythonrun.h GH-130396: Include stack margin for debug windows builds (GH-130554) 2025-02-25 19:26:21 +00:00
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 Fix a typo in Py_DECREF comment (#128387) 2025-02-25 11:10:40 +01:00
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-125604: Move _Py_AuditHookEntry, etc. Out of pycore_runtime.h (gh-125605) 2024-10-18 09:26:08 -06:00
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/