Add `MS_WINDOWS_DESKTOP`, `MS_WINDOWS_APPS`, `MS_WINDOWS_SYSTEM` and `MS_WINDOWS_GAMES` preprocessor definitions to allow switching off functionality missing from particular API partitions ("partitions" are used in Windows to identify overlapping subsets of APIs).
CPython only officially supports `MS_WINDOWS_DESKTOP` and `MS_WINDOWS_SYSTEM` (APPS is included by normal desktop builds, but APPS without DESKTOP is not covered). Other configurations are a convenience for people building their own runtimes.
`MS_WINDOWS_GAMES` is for the Xbox subset of the Windows API, which is also available on client OS, but is restricted compared to `MS_WINDOWS_DESKTOP`. These restrictions may change over time, as they relate to the build headers rather than the OS support, and so we assume that Xbox builds will use the latest available version of the GDK.
Enforcing (optionally) the restriction set by PEP 489 makes sense. Furthermore, this sets the stage for a potential restriction related to a per-interpreter GIL.
This change includes the following:
* add tests for extension module subinterpreter compatibility
* add _PyInterpreterConfig.check_multi_interp_extensions
* add Py_RTFLAGS_MULTI_INTERP_EXTENSIONS
* add _PyImport_CheckSubinterpIncompatibleExtensionAllowed()
* fail iff the module does not implement multi-phase init and the current interpreter is configured to check
https://github.com/python/cpython/issues/98627
This change is almost entirely moving code around and hiding import state behind internal API. We introduce no changes to behavior, nor to non-internal API. (Since there was already going to be a lot of churn, I took this as an opportunity to re-organize import.c into topically-grouped sections of code.) The motivation is to simplify a number of upcoming changes.
Specific changes:
* move existing import-related code to import.c, wherever possible
* add internal API for interacting with import state (both global and per-interpreter)
* use only API outside of import.c (to limit churn there when changing the location, etc.)
* consolidate the import-related state of PyInterpreterState into a single struct field (this changes layout slightly)
* add macros for import state in import.c (to simplify changing the location)
* group code in import.c into sections
*remove _PyState_AddModule()
https://github.com/python/cpython/issues/101758
A PyThreadState can be in one of many states in its lifecycle, represented by some status value. Those statuses haven't been particularly clear, so we're addressing that here. Specifically:
* made the distinct lifecycle statuses clear on PyThreadState
* identified expectations of how various lifecycle-related functions relate to status
* noted the various places where those expectations don't match the actual behavior
At some point we'll need to address the mismatches.
(This change also includes some cleanup.)
https://github.com/python/cpython/issues/59956
The objective of this change is to help make the GILState-related code easier to understand. This mostly involves moving code around and some semantically equivalent refactors. However, there are a also a small number of slight changes in structure and behavior:
* tstate_current is moved out of _PyRuntimeState.gilstate
* autoTSSkey is moved out of _PyRuntimeState.gilstate
* autoTSSkey is initialized earlier
* autoTSSkey is re-initialized (after fork) earlier
https://github.com/python/cpython/issues/59956
Fix a number of compile errors with GCC-12 on macOS:
1. In pylifecycle.c the compile rejects _Pragma within a declaration
2. posixmodule.c was missing a number of ..._RUNTIME macros for non-clang on macOS
3. _ctypes assumed that __builtin_available is always present on macOS
We actually don't move PyImport_Inittab. Instead, we make a copy that we keep on _PyRuntimeState and use only that after Py_Initialize(). We also prevent folks from modifying PyImport_Inittab (the best we can) after that point.
https://github.com/python/cpython/issues/81057
The global allocators were stored in 3 static global variables: _PyMem_Raw, _PyMem, and _PyObject. State for the "small block" allocator was stored in another 13. That makes a total of 16 global variables. We are moving all 16 to the _PyRuntimeState struct as part of the work for gh-81057. (If PEP 684 is accepted then we will follow up by moving them all to PyInterpreterState.)
https://github.com/python/cpython/issues/81057
As we consolidate global variables, we find some objects that are almost suitable to add to _PyRuntimeState.global_objects, but have some small/sneaky bit of per-interpreter state (e.g. a weakref list). We're adding PyInterpreterState.static_objects so we can move such objects there. (We'll removed the _not_used field once we've added others.)
https://github.com/python/cpython/issues/81057
* Adds EXIT_INTERPRETER instruction to exit PyEval_EvalDefault()
* Simplifies RETURN_VALUE, YIELD_VALUE and RETURN_GENERATOR instructions as they no longer need to check for entry frames.
We do the following:
* move the generated _PyUnicode_InitStaticStrings() to its own file
* move the generated _PyStaticObjects_CheckRefcnt() to its own file
* include pycore_global_objects.h in extension modules instead of pycore_runtime_init.h
These changes help us avoid including things that aren't needed.
https://github.com/python/cpython/issues/90868
Previously, the optional restrictions on subinterpreters were: disallow fork, subprocess, and threads. By default, we were disallowing all three for "isolated" interpreters. We always allowed all three for the main interpreter and those created through the legacy `Py_NewInterpreter()` API.
Those settings were a bit conservative, so here we've adjusted the optional restrictions to: fork, exec, threads, and daemon threads. The default for "isolated" interpreters disables fork, exec, and daemon threads. Regular threads are allowed by default. We continue always allowing everything For the main interpreter and the legacy API.
In the code, we add `_PyInterpreterConfig.allow_exec` and `_PyInterpreterConfig.allow_daemon_threads`. We also add `Py_RTFLAGS_DAEMON_THREADS` and `Py_RTFLAGS_EXEC`.
* 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.)
⚠️⚠️ Note for reviewers, hackers and fellow systems/low-level/compiler engineers ⚠️⚠️
If you have a lot of experience with this kind of shenanigans and want to improve the **first** version, **please make a PR against my branch** or **reach out by email** or **suggest code changes directly on GitHub**.
If you have any **refinements or optimizations** please, wait until the first version is merged before starting hacking or proposing those so we can keep this PR productive.
Static builtin types are finalized by calling _PyStaticType_Dealloc(). Before this change, we were skipping finalizing such a type if it still had subtypes (i.e. its tp_subclasses hadn't been cleared yet). The problem is that types hold several heap objects, which leak if we skip the type's finalization. This change addresses that.
For context, there's an old comment (from e9e3eab0b8) that says the following:
// If a type still has subtypes, it cannot be deallocated.
// A subtype can inherit attributes and methods of its parent type,
// and a type must no longer be used once it's deallocated.
However, it isn't clear that is actually still true. Clearing tp_dict should mean it isn't a problem.
Furthermore, the only subtypes that might still be around come from extension modules that didn't clean them up when unloaded (i.e. extensions that do not implement multi-phase initialization, AKA PEP 489). Those objects are already leaking, so this change doesn't change anything in that regard. Instead, this change means more objects gets cleaned up that before.
Seems in the past the copy of builtins was not made in some scenarios,
and the error was silenced. Write it now to stderr, so we have a chance
to see it.
It combines PyImport_ImportModule() and PyObject_GetAttrString()
and saves 4-6 lines of code on every use.
Add also _PyImport_GetModuleAttr() which takes Python strings as arguments.
This was added for bpo-40514 (gh-84694) to test out a per-interpreter GIL. However, it has since proven unnecessary to keep the experiment in the repo. (It can be done as a branch in a fork like normal.) So here we are removing:
* the configure option
* the macro
* the code enabled by the macro
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
Move _Py_GetAllocatedBlocks() and _PyObject_DebugMallocStats()
declarations to pycore_pymem.h. These functions are related to memory
allocators, not to the PyObject structure.
Add _PyUnicode_FiniTypes() function, called by
finalize_interp_types(). It clears these static types:
* EncodingMapType
* PyFieldNameIter_Type
* PyFormatterIter_Type
_PyStaticType_Dealloc() now does nothing if tp_subclasses
is not NULL.
Add 'static_exceptions' list to factorize code between
_PyExc_InitTypes() and _PyBuiltins_AddExceptions().
_PyExc_InitTypes() does nothing if it's not the main interpreter.
Sort exceptions in Lib/test/exception_hierarchy.txt.
* Move PyContext static types into object.c static_types list.
* Rename PyContextTokenMissing_Type to _PyContextTokenMissing_Type
and declare it in pycore_context.h.
* _PyHamtItems types are no long exported: replace PyAPI_DATA() with
extern.
Add _PyTypes_FiniTypes() best-effort function to clear static types:
don't deallocate a type if it still has subclasses.
remove_subclass() now sets tp_subclasses to NULL when removing the
last subclass.
"python -X showrefcount" now shows the total reference count after
clearing and destroyed the main Python interpreter. Previously, it
was shown before.
Py_FinalizeEx() now calls _PyDebug_PrintTotalRefs() after
finalize_interp_delete().
