Critical sections are helpers to replace the global interpreter lock
with finer grained locking. They provide similar guarantees to the GIL
and avoid the deadlock risk that plain locking involves. Critical
sections are implicitly ended whenever the GIL would be released. They
are resumed when the GIL would be acquired. Nested critical sections
behave as if the sections were interleaved.
This is partly to clear this stuff out of pystate.c, but also in preparation for moving some code out of _xxsubinterpretersmodule.c. This change also moves this stuff to the internal API (new: Include/internal/pycore_crossinterp.h). @vstinner did this previously and I undid it. Now I'm re-doing it. :/
Make sure that the internal C API is not tested by mistake by
_testcapi.
Undefine Py_BUILD_CORE_BUILTIN and Py_BUILD_CORE_MODULE macros in
Modules/_testcapi/parts.h: move code from _testcapimodule.c.
heaptype_relative.c and vectorcall_limited.c are using the limited C
API which is incompatible with the internal C API.
Move test_long_numbits() from _testcapi to _testinternalcapi since it
uses the internal C API "pycore_long.h".
Fix Modules/_testcapi/pyatomic.c: don't include Python.h directly,
just include _testcapi/parts.h.
Ajust "make check-c-globals" for these changes.
PyMutex is a one byte lock with fast, inlineable lock and unlock functions for the common uncontended case. The design is based on WebKit's WTF::Lock.
PyMutex is built using the _PyParkingLot APIs, which provides a cross-platform futex-like API (based on WebKit's WTF::ParkingLot). This internal API will be used for building other synchronization primitives used to implement PEP 703, such as one-time initialization and events.
This also includes tests and a mini benchmark in Tools/lockbench/lockbench.py to compare with the existing PyThread_type_lock.
Uncontended acquisition + release:
* Linux (x86-64): PyMutex: 11 ns, PyThread_type_lock: 44 ns
* macOS (arm64): PyMutex: 13 ns, PyThread_type_lock: 18 ns
* Windows (x86-64): PyMutex: 13 ns, PyThread_type_lock: 38 ns
PR Overview:
The primary purpose of this PR is to implement PyMutex, but there are a number of support pieces (described below).
* PyMutex: A 1-byte lock that doesn't require memory allocation to initialize and is generally faster than the existing PyThread_type_lock. The API is internal only for now.
* _PyParking_Lot: A futex-like API based on the API of the same name in WebKit. Used to implement PyMutex.
* _PyRawMutex: A word sized lock used to implement _PyParking_Lot.
* PyEvent: A one time event. This was used a bunch in the "nogil" fork and is useful for testing the PyMutex implementation, so I've included it as part of the PR.
* pycore_llist.h: Defines common operations on doubly-linked list. Not strictly necessary (could do the list operations manually), but they come up frequently in the "nogil" fork. ( Similar to https://man.freebsd.org/cgi/man.cgi?queue)
---------
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
Symbols of the C API should be prefixed by "Py_" to avoid conflict
with existing names in 3rd party C extensions on "#include <Python.h>".
test.pythoninfo now logs Py_C_RECURSION_LIMIT constant and other
_testcapi and _testinternalcapi constants.
Move the private _PyErr_WriteUnraisableMsg() functions to the
internal C API (pycore_pyerrors.h).
Move write_unraisable_exc() from _testcapi to _testinternalcapi.
Remove _PyErr_ChainExceptions(), _PyErr_ChainExceptions1() and
_PyErr_SetFromPyStatus() functions from the public C API.
* Move the private _PyErr_ChainExceptions() and
_PyErr_ChainExceptions1() function to the internal C API
(pycore_pyerrors.h).
* Move the private _PyErr_SetFromPyStatus() to the internal C API
(pycore_initconfig.h).
* No longer export the _PyErr_ChainExceptions() function.
* Move run_in_subinterp_with_config() from _testcapi to
_testinternalcapi.
Move private functions to the internal C API (pycore_dict.h):
* _PyDictView_Intersect()
* _PyDictView_New()
* _PyDict_ContainsId()
* _PyDict_DelItemId()
* _PyDict_DelItem_KnownHash()
* _PyDict_GetItemIdWithError()
* _PyDict_GetItem_KnownHash()
* _PyDict_HasSplitTable()
* _PyDict_NewPresized()
* _PyDict_Next()
* _PyDict_Pop()
* _PyDict_SetItemId()
* _PyDict_SetItem_KnownHash()
* _PyDict_SizeOf()
No longer export most of these functions.
Move also the _PyDictViewObject structure to the internal C API.
Move dict_getitem_knownhash() function from _testcapi to the
_testinternalcapi extension. Update test_capi.test_dict for this
change.
No longer export _PyUnicode_FromId() internal C API function.
Change comment style to "// comment" and add comment explaining why
other functions have to be exported.
Update Tools/build/generate_token.py to update Include/internal/pycore_token.h
comments.
* Add missing includes.
* Remove unused includes.
* Update old include/symbol names to newer names.
* Mention at least one included symbol.
* Sort includes.
* Update Tools/cases_generator/generate_cases.py used to generated
pycore_opcode_metadata.h.
* Update Parser/asdl_c.py used to generate pycore_ast.h.
* Cleanup also includes in _testcapimodule.c and _testinternalcapi.c.
The _xxsubinterpreters module should not rely on internal API. Some of the functions it uses were recently moved there however. Here we move them back (and expose them properly).
Move private _PyMem functions to the internal C API (pycore_pymem.h):
* _PyMem_GetCurrentAllocatorName()
* _PyMem_RawStrdup()
* _PyMem_RawWcsdup()
* _PyMem_Strdup()
No longer export these functions.
Move pymem_getallocatorsname() function from _testcapi to _testinternalcapi,
since the API moved to the internal C API.
Move private debug _PyObject functions to the internal C API
(pycore_object.h):
* _PyDebugAllocatorStats()
* _PyObject_CheckConsistency()
* _PyObject_DebugTypeStats()
* _PyObject_IsFreed()
No longer export most of these functions, except of
_PyObject_IsFreed().
Move test functions using _PyObject_IsFreed() from _testcapi to
_testinternalcapi. check_pyobject_is_freed() test no longer catch
_testcapi.error: the tested function cannot raise _testcapi.error.
Move the private _PyInterpreterID C API to the internal C API: add a
new pycore_interp_id.h header file.
Remove Include/interpreteridobject.h and
Include/cpython/interpreteridobject.h header files.
Remove private pylifecycle.h functions: move them to the internal C
API ( pycore_atexit.h, pycore_pylifecycle.h and pycore_signal.h). No
longer export most of these functions.
Move _testcapi.test_atexit() to _testinternalcapi.
Remove private _PyUnicode_TransformDecimalAndSpaceToASCII() and other
private _PyUnicode C API functions: move them to the internal C API
(pycore_unicodeobject.h). No longer most of these functions.
Replace _testcapi.unicode_transformdecimalandspacetoascii() with
_testinternal._PyUnicode_TransformDecimalAndSpaceToASCII().
Remove private _PyThreadState and _PyInterpreterState C API
functions: move them to the internal C API (pycore_pystate.h and
pycore_interp.h). Don't export most of these functions anymore, but
still export functions used by tests.
Remove _PyThreadState_Prealloc() and _PyThreadState_Init() from the C
API, but keep it in the stable API.
* Remove private _PyTraceMalloc C API functions: move them to the
internal C API.
* Don't export most of these functions anymore, but still export
_PyTraceMalloc_GetTraceback() used by tests.
* Rename Include/tracemalloc.h to Include/cpython/tracemalloc.h
Remove the "cpython/pytime.h" header file: it only contained private
functions. Move functions to the internal pycore_time.h header file.
Move tests from _testcapi to _testinternalcapi. Rename also test
methods to have the same name than tested C functions.
No longer export these functions:
* _PyTime_Add()
* _PyTime_As100Nanoseconds()
* _PyTime_FromMicrosecondsClamp()
* _PyTime_FromTimespec()
* _PyTime_FromTimeval()
* _PyTime_GetPerfCounterWithInfo()
* _PyTime_MulDiv()
Added a new, experimental, tracing optimizer and interpreter (a.k.a. "tier 2"). This currently pessimizes, so don't use yet -- this is infrastructure so we can experiment with optimizing passes. To enable it, pass ``-Xuops`` or set ``PYTHONUOPS=1``. To get debug output, set ``PYTHONUOPSDEBUG=N`` where ``N`` is a debug level (0-4, where 0 is no debug output and 4 is excessively verbose).
All of this code is likely to change dramatically before the 3.13 feature freeze. But this is a first step.
For a while now, pending calls only run in the main thread (in the main interpreter). This PR changes things to allow any thread run a pending call, unless the pending call was explicitly added for the main thread to run.
We also add PyInterpreterState.ceval.own_gil to record if the interpreter actually has its own GIL.
Note that for now we don't actually respect own_gil; all interpreters still share the one GIL. However, PyInterpreterState.ceval.own_gil does reflect PyInterpreterConfig.own_gil. That lie is a temporary one that we will fix when the GIL really becomes per-interpreter.
Here we are doing no more than adding the value for Py_mod_multiple_interpreters and using it for stdlib modules. We will start checking for it in gh-104206 (once PyInterpreterState.ceval.own_gil is added in gh-104204).
