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.
* As most of `test_embed` now uses `Py_InitializeFromConfig`, add
a specific test case to cover `Py_Initialize` (and `Py_InitializeEx`)
* Rename `_testembed` init helper to clarify the API used
* Add a `PyConfig_Clear` call in `Py_InitializeEx` to make
the code more obviously correct (it already didn't leak as
none of the dynamically allocated config fields were being
populated, but it's clearer if the wrappers follow the
documented API usage guidelines)
(see https://github.com/python/cpython/issues/98608)
This change does the following:
1. change the argument to a new `_PyInterpreterConfig` struct
2. rename the function to `_Py_NewInterpreterFromConfig()`, inspired by `Py_InitializeFromConfig()` (takes a `_PyInterpreterConfig` instead of `isolated_subinterpreter`)
3. split up the boolean `isolated_subinterpreter` into the corresponding multiple granular settings
* allow_fork
* allow_subprocess
* allow_threads
4. add `PyInterpreterState.feature_flags` to store those settings
5. add a function for checking if a feature is enabled on an opaque `PyInterpreterState *`
6. drop `PyConfig._isolated_interpreter`
The existing default (see `Py_NewInterpeter()` and `Py_Initialize*()`) allows fork, subprocess, and threads and the optional "isolated" interpreter (see the `_xxsubinterpreters` module) disables all three. None of that changes here; the defaults are preserved.
Note that the given `_PyInterpreterConfig` will not be used outside `_Py_NewInterpreterFromConfig()`, nor preserved. This contrasts with how `PyConfig` is currently preserved, used, and even modified outside `Py_InitializeFromConfig()`. I'd rather just avoid that mess from the start for `_PyInterpreterConfig`. We can preserve it later if we find an actual need.
This change allows us to follow up with a number of improvements (e.g. stop disallowing subprocess and support disallowing exec instead).
(Note that this PR adds "private" symbols. We'll probably make them public, and add docs, in a separate change.)
It had to live as a global outside of PyConfig for stable ABI reasons in
the pre-3.12 backports.
This removes the `_Py_global_config_int_max_str_digits` and gets rid of
the equivalent field in the internal `struct _is PyInterpreterState` as
code can just use the existing nested config struct within that.
Adds tests to verify unique settings and configs in subinterpreters.
Add the -P command line option and the PYTHONSAFEPATH environment
variable to not prepend a potentially unsafe path to sys.path.
* Add sys.flags.safe_path flag.
* Add PyConfig.safe_path member.
* Programs/_bootstrap_python.c uses config.safe_path=0.
* Update subprocess._optim_args_from_interpreter_flags() to handle
the -P command line option.
* Modules/getpath.py sets safe_path to 1 if a "._pth" file is
present.
We're no longer using _Py_IDENTIFIER() (or _Py_static_string()) in any core CPython code. It is still used in a number of non-builtin stdlib modules.
The replacement is: PyUnicodeObject (not pointer) fields under _PyRuntimeState, statically initialized as part of _PyRuntime. A new _Py_GET_GLOBAL_IDENTIFIER() macro facilitates lookup of the fields (along with _Py_GET_GLOBAL_STRING() for non-identifier strings).
https://bugs.python.org/issue46541#msg411799 explains the rationale for this change.
The core of the change is in:
* (new) Include/internal/pycore_global_strings.h - the declarations for the global strings, along with the macros
* Include/internal/pycore_runtime_init.h - added the static initializers for the global strings
* Include/internal/pycore_global_objects.h - where the struct in pycore_global_strings.h is hooked into _PyRuntimeState
* Tools/scripts/generate_global_objects.py - added generation of the global string declarations and static initializers
I've also added a --check flag to generate_global_objects.py (along with make check-global-objects) to check for unused global strings. That check is added to the PR CI config.
The remainder of this change updates the core code to use _Py_GET_GLOBAL_IDENTIFIER() instead of _Py_IDENTIFIER() and the related _Py*Id functions (likewise for _Py_GET_GLOBAL_STRING() instead of _Py_static_string()). This includes adding a few functions where there wasn't already an alternative to _Py*Id(), replacing the _Py_Identifier * parameter with PyObject *.
The following are not changed (yet):
* stop using _Py_IDENTIFIER() in the stdlib modules
* (maybe) get rid of _Py_IDENTIFIER(), etc. entirely -- this may not be doable as at least one package on PyPI using this (private) API
* (maybe) intern the strings during runtime init
https://bugs.python.org/issue46541
* _testembed_Py_Initialize() now uses the PyConfig API, rather than
deprecated Py_SetProgramName().
* Reduce INIT_LOOPS from 16 to 4: test_embed now takes 8.7 seconds
rather than 14.7 seconds.
Add _PyStructSequence_FiniType() and _PyStaticType_Dealloc()
functions to finalize a structseq static type in Py_Finalize().
Currrently, these functions do nothing if Python is built in release
mode.
Clear static types:
* AsyncGenHooksType: sys.set_asyncgen_hooks()
* FlagsType: sys.flags
* FloatInfoType: sys.float_info
* Hash_InfoType: sys.hash_info
* Int_InfoType: sys.int_info
* ThreadInfoType: sys.thread_info
* UnraisableHookArgsType: sys.unraisablehook
* VersionInfoType: sys.version
* WindowsVersionType: sys.getwindowsversion()
Rename PyConfig.no_debug_ranges to PyConfig.code_debug_ranges and
invert the value.
Document -X no_debug_ranges and PYTHONNODEBUGRANGES env var in
PyConfig.code_debug_ranges documentation.
Currently custom modules (the array set on PyImport_FrozenModules) replace all the frozen stdlib modules. That can be problematic and is unlikely to be what the user wants. This change treats the custom frozen modules as additions instead. They take precedence over all other frozen modules except for those needed to bootstrap the import system. If the "code" field of an entry in the custom array is NULL then that frozen module is treated as disabled, which allows a custom entry to disable a frozen stdlib module.
This change allows us to get rid of is_essential_frozen_module() and simplifies the logic for which frozen modules should be ignored.
https://bugs.python.org/issue45395
Remove useless calls to PyThread_exit_thread() in two unit tests of
_testcapi and _testembed modules.
Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>
Py_RunMain() now resets PyImport_Inittab to its initial value at
exit. It must be possible to call PyImport_AppendInittab() or
PyImport_ExtendInittab() at each Python initialization.
Deprecate the following functions to configure the Python
initialization:
* PySys_AddWarnOption()
* PySys_AddWarnOptionUnicode()
* PySys_AddXOption()
* PySys_HasWarnOptions()
* Py_SetPath()
* Py_SetProgramName()
* Py_SetPythonHome()
* Py_SetStandardStreamEncoding()
* _Py_SetProgramFullPath()
Use the new PyConfig API of the Python Initialization Configuration
instead (PEP 587).
Add frozen modules to sys.stdlib_module_names. For example, add
"_frozen_importlib" and "_frozen_importlib_external" names.
Add "list_frozen" command to Programs/_testembed.
The path configuration is now computed in the "main" initialization.
The core initialization no longer computes it.
* Add _PyConfig_Read() function to read the configuration without
computing the path configuration.
* pyinit_core() no longer computes the path configuration: it is now
computed by init_interp_main().
* The path configuration output members of PyConfig are now optional:
* executable
* base_executable
* prefix
* base_prefix
* exec_prefix
* base_exec_prefix
* _PySys_UpdateConfig() now skips NULL strings in PyConfig.
* _testembed: Rename test_set_config() to test_init_set_config() for
consistency with other tests.
* Inline _PyInterpreterState_SetConfig(): replace it with
_PyConfig_Copy().
* Add _PyErr_SetFromPyStatus()
* Add _PyInterpreterState_GetConfigCopy()
* Add a new _PyInterpreterState_SetConfig() function.
* Add an unit which gets, modifies, and sets the config.
This commit removes the old parser, the deprecated parser module, the old parser compatibility flags and environment variables and all associated support code and documentation.
Export explicitly the Py_GetArgcArgv() function to the C API and
document the function. Previously, it was exported implicitly which
no longer works since Python is built with -fvisibility=hidden.
* Add PyConfig._orig_argv member.
* Py_InitializeFromConfig() no longer calls _PyConfig_Write() twice.
* PyConfig_Read() no longer initializes Py_GetArgcArgv(): it is now
_PyConfig_Write() responsibility.
* _PyConfig_Write() result type becomes PyStatus instead of void.
* Write an unit test on Py_GetArgcArgv().
An isolated subinterpreter cannot spawn threads, spawn a child
process or call os.fork().
* Add private _Py_NewInterpreter(isolated_subinterpreter) function.
* Add isolated=True keyword-only parameter to
_xxsubinterpreters.create().
* Allow again os.fork() in "non-isolated" subinterpreters.
* Rename PyConfig.use_peg to _use_peg_parser
* Document PyConfig._use_peg_parser and mark it a deprecated
* Mark -X oldparser option and PYTHONOLDPARSER env var as deprecated
in the documentation.
* Add use_old_parser() and skip_if_new_parser() to test.support
* Remove sys.flags.use_peg: use_old_parser() uses
_testinternalcapi.get_configs() instead.
* Enhance test_embed tests
* subprocess._args_from_interpreter_flags() copies -X oldparser
For now, we'll rely on the fact that the config structures aren't covered by the stable ABI.
We may revisit this in the future if we further explore the idea of offering a stable embedding API.
(cherry picked from commit bdace21b76)
Fix warnings options priority: PyConfig.warnoptions has the highest
priority, as stated in the PEP 587.
* Document options order in PyConfig.warnoptions documentation.
* Make PyWideStringList_INIT macro private: replace "Py" prefix
with "_Py".
* test_embed: add test_init_warnoptions().
Add a new struct_size field to PyPreConfig and PyConfig structures to
allow to modify these structures in the future without breaking the
backward compatibility.
* Replace private _config_version field with public struct_size field
in PyPreConfig and PyConfig.
* Public PyPreConfig_InitIsolatedConfig() and
PyPreConfig_InitPythonConfig()
return type becomes PyStatus, instead of void.
* Internal _PyConfig_InitCompatConfig(),
_PyPreConfig_InitCompatConfig(), _PyPreConfig_InitFromConfig(),
_PyPreConfig_InitFromPreConfig() return type becomes PyStatus,
instead of void.
* Remove _Py_CONFIG_VERSION
* Update the Initialization Configuration documentation.
Explicitly preinitializes with a Python preconfiguration to avoid
Py_SetPath() implicit preinitialization with a compat
preconfiguration.
Fix also test_init_setpath() and test_init_setpythonhome() on macOS:
use self.test_exe as the executable (and base_executable), rather
than shutil.which('python3').
Eddie Elizondo
chgnrdv
Kumar Aditya
Nick Coghlan
Eric Snow
Gregory P. Smith
Brandt Bucher
Matthias Görgens
Pablo Galindo Salgado
neonene
Victor Stinner
Dong-hee Na
Nikita Sobolev
Ammar Askar
Konge
Sandro Mani
Victor Stinner