memcopy'ing arbitrary values to _Bool variable triggers undefined
behaviour. Avoid this.
We assume that `false` is represented by all zero bytes.
Credits to Alex Gaynor.
Co-authored-by: Sam Gross <colesbury@gmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Petr Viktorin <encukou@gmail.com>
* Add definitions for "context", "current context", and "context
management protocol".
* Update related definitions to be consistent with the new
definitions.
* Restructure the documentation for the `contextvars.Context` class
to prepare for adding context manager support, and for consistency
with the definitions.
* Use `testcode` and `testoutput` to test the `Context.run` example.
* Expand the documentation for the `Py_CONTEXT_EVENT_ENTER` and
`Py_CONTEXT_EVENT_EXIT` events to clarify and to prepare for
planned changes.
Replace the private _PyUnicodeWriter with the public PyUnicodeWriter.
Replace PyObject_Repr() + _PyUnicodeWriter_WriteStr()
with PyUnicodeWriter_WriteRepr().
As argparse now detects by default when the code was run as a module.
This leads to using the actual executable name instead of simply "python"
to display in the usage message ("usage: python -m ...").
Fix a crash caused by immortal interned strings being shared between
sub-interpreters that use basic single-phase init. In that case, the string
can be used by an interpreter that outlives the interpreter that created and
interned it. For interpreters that share obmalloc state, also share the
interned dict with the main interpreter.
This is an un-revert of gh-124646 that then addresses the Py_TRACE_REFS
failures identified by gh-124785.
Each of the `LOAD_GLOBAL` specializations is implemented roughly as:
1. Load keys version.
2. Load cached keys version.
3. Deopt if (1) and (2) don't match.
4. Load keys.
5. Load cached index into keys.
6. Load object from (4) at offset from (5).
This is not thread-safe in free-threaded builds; the keys object may be replaced
in between steps (3) and (4).
This change refactors the specializations to avoid reloading the keys object and
instead pass the keys object from guards to be consumed by downstream uops.
* Update `__future__.rst`
Fixed typo in the sentence :pep:`649`: *Deferred evaluation of annotations using descriptors* - James McCarthy
* Update `__future__.rst`
Fixed sphinx formatting
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Barry Warsaw <barry@python.org>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
This allows testing Y2038 with system time set to after that,
so that actual Y2038 issues can be exposed, and not masked
by expired certificate errors.
Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
* Replace unicode_compare_eq() with unicode_eq().
* Use unicode_eq() in setobject.c.
* Replace _PyUnicode_EQ() with _PyUnicode_Equal().
* Remove unicode_compare_eq() and _PyUnicode_EQ().
* Make slices marshallable
* Emit slices as constants
* Update Python/marshal.c
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
* Refactor codegen_slice into two functions so it
always has the same net effect
* Fix for free-threaded builds
* Simplify marshal loading of slices
* Only return SUCCESS/ERROR from codegen_slice
---------
Co-authored-by: Mark Shannon <mark@hotpy.org>
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Stop the world when invalidating function versions
The tier1 interpreter specializes `CALL` instructions based on the values
of certain function attributes (e.g. `__code__`, `__defaults__`). The tier1
interpreter uses function versions to verify that the attributes of a function
during execution of a specialization match those seen during specialization.
A function's version is initialized in `MAKE_FUNCTION` and is invalidated when
any of the critical function attributes are changed. The tier1 interpreter stores
the function version in the inline cache during specialization. A guard is used by
the specialized instruction to verify that the version of the function on the operand
stack matches the cached version (and therefore has all of the expected attributes).
It is assumed that once the guard passes, all attributes will remain unchanged
while executing the rest of the specialized instruction.
Stopping the world when invalidating function versions ensures that all critical
function attributes will remain unchanged after the function version guard passes
in free-threaded builds. It's important to note that this is only true if the remainder
of the specialized instruction does not enter and exit a stop-the-world point.
We will stop the world the first time any of the following function attributes
are mutated:
- defaults
- vectorcall
- kwdefaults
- closure
- code
This should happen rarely and only happens once per function, so the performance
impact on majority of code should be minimal.
Additionally, refactor the API for manipulating function versions to more clearly
match the stated semantics.
If the PYTHON_BASIC_REPL environment variable is set, the site module
no longer imports the _pyrepl module.
Moreover, the site module now respects -E and -I command line
options: ignore PYTHON_BASIC_REPL in this case.
Sergey B Kirpichev
Donghee Na
Irit Katriel
Victor Stinner
Adam Turner
Richard Hansen
Serhiy Storchaka
Pablo Galindo Salgado
Savannah Ostrowski
Eric Snow
mpage
Mark Shannon
Hugo van Kemenade
JamesMcCarthy21
Tomas R.
Alex Waygood
Alyssa Coghlan
Petr Viktorin
Alexander Kanavin
Furkan Onder
musvaage
Jelle Zijlstra
Mariusz Felisiak
Raymond Hettinger
spacemanspiff2007
Michael Droettboom
Cody Maloney
Kumar Aditya