_PyArg_Parser holds static global data generated for modules by Argument Clinic. The _PyArg_Parser.kwtuple field is a tuple object, even though it's stored within a static global. In some cases the tuple is statically allocated and thus it's okay that it gets shared by multiple interpreters. However, in other cases the tuple is set lazily, allocated from the heap using the active interprepreter at the point the tuple is needed.
This is a problem once that interpreter is destroyed since _PyArg_Parser.kwtuple becomes at dangling pointer, leading to crashes. It isn't a problem if the tuple is allocated under the main interpreter, since its lifetime is bound to the lifetime of the runtime. The solution here is to temporarily switch to the main interpreter. The alternative would be to always statically allocate the tuple.
This change also fixes a bug where only the most recent parser was added to the global linked list.
This ensures we don't lose races that occur in subprocesses or
interleave races from workers running in parallel.
Log files are collected and packaged into a zipfile that can be
downloaded from the "Artifacts" section of the workflow run.
`_Py_qsbr_unregister` is called when the PyThreadState is already
detached, so the access to `tstate->qsbr` isn't safe without locking the
shared mutex. Grab the `struct _qsbr_shared` from the interpreter
instead.
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.
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.
The module itself is a thin wrapper around calls to functions in
`Python/codecs.c`, so that's where the meaningful changes happened:
- Move codecs-related state that lives on `PyInterpreterState` to a
struct declared in `pycore_codecs.h`.
- In free-threaded builds, add a mutex to `codecs_state` to synchronize
operations on `search_path`. Because `search_path_mutex` is used as a
normal mutex and not a critical section, we must be extremely careful
with operations called while holding it.
- The codec registry is explicitly initialized as part of
`_PyUnicode_InitEncodings` to simplify thread-safety.
The code for Tier 2 is now only compiled when configured
with `--enable-experimental-jit[=yes|interpreter]`.
We drop support for `PYTHON_UOPS` and -`Xuops`,
but you can disable the interpreter or JIT
at runtime by setting `PYTHON_JIT=0`.
You can also build it without enabling it by default
using `--enable-experimental-jit=yes-off`;
enable with `PYTHON_JIT=1`.
On Windows, the `build.bat` script supports
`--experimental-jit`, `--experimental-jit-off`,
`--experimental-interpreter`.
In the C code, `_Py_JIT` is defined as before
when the JIT is enabled; the new variable
`_Py_TIER2` is defined when the JIT *or* the
interpreter is enabled. It is actually a bitmask:
1: JIT; 2: default-off; 4: interpreter.
Makes sys.settrace, sys.setprofile, and monitoring generally thread-safe.
Mostly uses a stop-the-world approach and synchronization around the code object's _co_instrumentation_version. There may be a little bit of extra synchronization around the monitoring data that's required to be TSAN clean.
Quiet erroneous TSAN reports of data races in `_PySeqLock`
TSAN reports a couple of data races between the compare/exchange in
`_PySeqLock_LockWrite` and the non-atomic loads in `_PySeqLock_{Abandon,Unlock}Write`.
This is another instance of TSAN incorrectly modeling failed compare/exchange
as a write instead of a load.
Fix data races in the method cache in free-threaded builds
These are technically data races, but I think they're benign (to
the extent that that is actually possible). We update cache entries
non-atomically but read them atomically from another thread, and there's
nothing that establishes a happens-before relationship between the
reads and writes that I can see.
Additionally, reduce the iterations for a few weakref tests that would
otherwise take a prohibitively long amount of time (> 1 hour) when TSAN
is enabled and the GIL is disabled.
* Move ifndef_symbols, includes and add_include() from Clinic to
Codegen. Add a 'codegen' (Codegen) attribute to Clinic.
* Remove libclinic.crenderdata module: move code to libclinic.codegen.
* BlockPrinter.print_block(): remove unused 'limited_capi' argument.
Remove also 'core_includes' parameter.
* Add get_includes() methods.
* Make Codegen.ifndef_symbols private.
* Make Codegen.includes private.
* Make CConverter.includes private.
Introduce a unified 16-bit backoff counter type (``_Py_BackoffCounter``),
shared between the Tier 1 adaptive specializer and the Tier 2 optimizer. The
API used for adaptive specialization counters is changed but the behavior is
(supposed to be) identical.
The behavior of the Tier 2 counters is changed:
- There are no longer dynamic thresholds (we never varied these).
- All counters now use the same exponential backoff.
- The counter for ``JUMP_BACKWARD`` starts counting down from 16.
- The ``temperature`` in side exits starts counting down from 64.
Add libclinic.clanguage module and move the following classes and
functions there:
* CLanguage
* declare_parser()
Add libclinic.codegen and move the following classes there:
* BlockPrinter
* BufferSeries
* Destination
Move the following functions to libclinic.function:
* permute_left_option_groups()
* permute_optional_groups()
* permute_right_option_groups()
* Add a new create_parser_namespace() function for
PythonParser to pass objects to executed code.
* In run_clinic(), list converters using 'converters' and
'return_converters' dictionarties.
* test_clinic: add 'object()' return converter.
* Use also create_parser_namespace() in eval_ast_expr().
Co-authored-by: Erlend E. Aasland <erlend@python.org>
I added it quite a while ago as a strategy for managing interpreter lifetimes relative to the PEP 554 (now 734) implementation. Relatively recently I refactored that implementation to no longer rely on InterpreterID objects. Thus now I'm removing it.
Add Py_GetConstant() and Py_GetConstantBorrowed() functions.
In the limited C API version 3.13, getting Py_None, Py_False,
Py_True, Py_Ellipsis and Py_NotImplemented singletons is now
implemented as function calls at the stable ABI level to hide
implementation details. Getting these constants still return borrowed
references.
Add _testlimitedcapi/object.c and test_capi/test_object.py to test
Py_GetConstant() and Py_GetConstantBorrowed() functions.
Keep Tools/build/deepfreeze.py around (we may repurpose it for deepfreezing non-code objects),
and keep basic "clean" targets that remove the output of former deep-freeze activities,
to keep the build directories of current devs clean.
* Move Block and BlockParser classes to a new libclinic.block_parser
module.
* Move Language and PythonLanguage classes to a new
libclinic.language module.
The fildes converter of Argument Clinic now always call
PyObject_AsFileDescriptor(), not only for the limited C API.
The _PyLong_FileDescriptor_Converter() converter stays as a fallback
when PyObject_AsFileDescriptor() cannot be used.
Eric Snow
Arnon Yaari
Seth Michael Larson
Brandt Bucher
Miro Hrončok
Michał Górny
mpage
Mark Shannon
Alex Turner
Brett Simmers
trag1c
Pablo Galindo Salgado
dependabot[bot]
Tian Gao
Irit Katriel
Savannah Ostrowski
Jelle Zijlstra
Andrej
Guido van Rossum
Steve Dower
Alex Turner
Xie Yanbo
Dino Viehland
David Rubin
neonene
Jeff Glass
Victor Stinner
Erlend E. Aasland
Ken Jin
Michael Droettboom
Sam Gross
Donghee Na