We tried this before with a dict and for all interned strings. That ran into problems due to interpreter isolation. However, exclusively using a per-interpreter cache caused some inconsistency that can eliminate the benefit of interning. Here we circle back to using a global cache, but only for statically allocated strings. We also use a more-basic _Py_hashtable_t for that global cache instead of a dict.
Ideally we would only have the global cache, but the optional isolation of each interpreter's allocator means that a non-static string object must not outlive its interpreter. Thus we would have to store a copy of each such interned string in the global cache, tied to the main interpreter.
(cherry-picked from commit b72947a8d2)
gh-107913: Fix possible losses of OSError error codes (GH-107930)
Functions like PyErr_SetFromErrno() and SetFromWindowsErr() should be
called immediately after using the C API which sets errno or the Windows
error code.
(cherry picked from commit 2b15536fa9)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
gh-105699: Fix an Interned Strings Crasher (gh-106930)
A static (process-global) str object must only have its "interned" state cleared when no longer interned in any interpreters. They are the only ones that can be shared by interpreters so we don't have to worry about any other str objects.
We trigger clearing the state with the main interpreter, since no other interpreters may exist at that point and _PyUnicode_ClearInterned() is only called during interpreter finalization.
We do not address here the fact that a string will only be interned in the first interpreter that interns it. In any subsequent interpreters str.state.interned is already set so _PyUnicode_InternInPlace() will skip it. That needs to be addressed separately from fixing the crasher.
(cherry picked from commit 87e7cb09e4)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
gh-105699: Fix a Crasher Related to a Deprecated Global Variable (gh-106923)
There was a slight race in _Py_ClearFileSystemEncoding() (when called from _Py_SetFileSystemEncoding()), between freeing the value and setting the variable to NULL, which occasionally caused crashes when multiple isolated interpreters were used. (Notably, I saw at least 10 different, seemingly unrelated spooky-action-at-a-distance, ways this crashed. Yay, free threading!) We avoid the problem by only setting the global variables with the main interpreter (i.e. runtime init).
(cherry picked from commit 0ba07b2108)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
Bail on first error to prevent exceptions from possibly being overwritten.
(cherry picked from commit 555be81026)
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
* Support for conversion specifiers o (octal) and X (uppercase hexadecimal).
* Support for length modifiers j (intmax_t) and t (ptrdiff_t).
* Length modifiers are now applied to all integer conversions.
* Support for wchar_t C strings (%ls and %lV).
* Support for variable width and precision (*).
* Support for flag - (left alignment).
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).
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.
We can revisit the options for keeping it global later, if desired. For now the approach seems quite complex, so we've gone with the simpler isolation solution in the meantime.
https://github.com/python/cpython/issues/100227
This reverts commit 87be8d9.
This approach to keeping the interned strings safe is turning out to be too complex for my taste (due to obmalloc isolation). For now I'm going with the simpler solution, making the dict per-interpreter. We can revisit that later if we want a sharing solution.
This is effectively two changes. The first (the bulk of the change) is where we add _Py_AddToGlobalDict() (and _PyRuntime.cached_objects.main_tstate, etc.). The second (much smaller) change is where we update PyUnicode_InternInPlace() to use _Py_AddToGlobalDict() instead of calling PyDict_SetDefault() directly.
Basically, _Py_AddToGlobalDict() is a wrapper around PyDict_SetDefault() that should be used whenever we need to add a value to a runtime-global dict object (in the few cases where we are leaving the container global rather than moving it to PyInterpreterState, e.g. the interned strings dict). _Py_AddToGlobalDict() does all the necessary work to make sure the target global dict is shared safely between isolated interpreters. This is especially important as we move the obmalloc state to each interpreter (gh-101660), as well as, potentially, the GIL (PEP 684).
https://github.com/python/cpython/issues/100227
* move _PyRuntime.global_objects.interned to _PyRuntime.cached_objects.interned_strings (and use _Py_CACHED_OBJECT())
* rename _PyRuntime.global_objects to _PyRuntime.static_objects
(This also relates to gh-96075.)
https://github.com/python/cpython/issues/90111
builtins and extension module functions and methods that expect boolean values for parameters now accept any Python object rather than just a bool or int type. This is more consistent with how native Python code itself behaves.
Fix potential race condition in code patterns:
* Replace "Py_DECREF(var); var = new;" with "Py_SETREF(var, new);"
* Replace "Py_XDECREF(var); var = new;" with "Py_XSETREF(var, new);"
* Replace "Py_CLEAR(var); var = new;" with "Py_XSETREF(var, new);"
Other changes:
* Replace "old = var; var = new; Py_DECREF(var)"
with "Py_SETREF(var, new);"
* Replace "old = var; var = new; Py_XDECREF(var)"
with "Py_XSETREF(var, new);"
* And remove the "old" variable.
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
The os module and the PyUnicode_FSDecoder() function no longer accept
bytes-like paths, like bytearray and memoryview types: only the exact
bytes type is accepted for bytes strings.
asciilib_count() is the same than ucs1lib_count(): the code is not
specialized for ASCII strings, so it's not worth it to have a
separated function. Remove asciilib_count() function.
An unrecognized format character in PyUnicode_FromFormat() and
PyUnicode_FromFormatV() now sets a SystemError.
In previous versions it caused all the rest of the format string to be
copied as-is to the result string, and any extra arguments discarded.
This is the first of several precursors to storing tp_subclasses (and tp_weaklist) on the interpreter state for static builtin types.
We do the following:
* add `_PyStaticType_InitBuiltin()`
* add `_Py_TPFLAGS_STATIC_BUILTIN`
* set it on all static builtin types in `_PyStaticType_InitBuiltin()`
* shuffle some code around to be able to use _PyStaticType_InitBuiltin()
* rename `_PyStructSequence_InitType()` to `_PyStructSequence_InitBuiltinWithFlags()`
* add `_PyStructSequence_InitBuiltin()`.
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
Avoid _PyCodec_Lookup() and PyCodec_LookupError() for most common
built-in encodings and error handlers to avoid creating a temporary
Unicode string object, whereas these encodings and error handlers are
known to be valid.
Remove the PyUnicode_InternImmortal() function and the
SSTATE_INTERNED_IMMORTAL macro.
The PyUnicode_InternImmortal() function is still exported in the
stable ABI. The function is removed from the API.
PyASCIIObject.state.interned size is now a single bit, rather than 2
bits.
Keep SSTATE_NOT_INTERNED and SSTATE_INTERNED_MORTAL macros for
backward compatibility, but no longer use them internally since the
interned member is now a single bit and so can only have two values
(interned or not interned).
Update stats of _PyUnicode_ClearInterned().
Replace "(PyCFunction)(void(*)(void))func" cast with
_PyCFunction_CAST(func).
Change generated by the command:
sed -i -e \
's!(PyCFunction)(void(\*)(void)) *\([A-Za-z0-9_]\+\)!_PyCFunction_CAST(\1)!g' \
$(find -name "*.c")
