This PR adds the ability to enable the GIL if it was disabled at
interpreter startup, and modifies the multi-phase module initialization
path to enable the GIL when loading a module, unless that module's spec
includes a slot indicating it can run safely without the GIL.
PEP 703 called the constant for the slot `Py_mod_gil_not_used`; I went
with `Py_MOD_GIL_NOT_USED` for consistency with gh-104148.
A warning will be issued up to once per interpreter for the first
GIL-using module that is loaded. If `-v` is given, a shorter message
will be printed to stderr every time a GIL-using module is loaded
(including the first one that issues a warning).
This is unsupported. Note that `skip_unless_reliable_fork()` checks for
the conditions used by the decorators that were removed, along with checking
for TSAN.
The function returns `True` or `False` depending on whether the GIL is
currently enabled. In the default build, it always returns `True`
because the GIL is always enabled.
Most module names are interned and immortalized, but the main
module was not. This partially addresses a scaling bottleneck in the
free-threaded when creating closure concurrently in the main module.
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 `time.sleep()` call should happen before the GC to give the worker
threads time to clean-up their remaining references to objs.
Additionally, use `support.gc_collect()` instead of `gc.collect()`
just in case the extra GC calls matter.
* Target _FOR_ITER_TIER_TWO at POP_TOP following the matching END_FOR
* Modify _GUARD_NOT_EXHAUSTED_RANGE, _GUARD_NOT_EXHAUSTED_LIST and _GUARD_NOT_EXHAUSTED_TUPLE so that they also target the POP_TOP following the matching END_FOR
Now inspect.signature() supports references to the module globals in
parameter defaults on methods in extension modules. Previously it was
only supported in functions. The workaround was to specify the fully
qualified name, including the module name.
* docs: tiny grammar change: "pointed by" -> "pointed to by"
This commit uses "file pointed to by" to replace "file pointed by" in
- doc for shutil.copytree
- docstring for shutil.copytree
- docstring _abc.PathBase.open
- docstring for pathlib.Path.open
- doc for os.copy_file_range
- doc for os.splice
The docs use "file pointed to by" more frequently than
"file pointed by". So, this commit replaces the uses of
"file pointed by" in order to make the uses consistent
through the docs.
```bash
$ grep -ri 'pointed to by' cpython/
```
yields more results than
```bash
$ grep -ri 'pointed by' cpython/
```
Separately:
There are two occurrences of "tree pointed by":
- cpython/Doc/library/xml.etree.elementtree.rst for
`xml.etree.ElementInclude.include`
- cpython/Lib/xml/etree/ElementInclude.py for `include`
For those uses of "tree pointed by", I expect "tree pointed to by"
instead. However, I found enough uses online of (a) "tree pointed by"
rather than (b) "tree pointed to by" to convince me that (a) is in
common use.
So, this commit does not replace those occurrences of "tree pointed by"
to "tree pointed to by". But I will replace them if a reviewer
believes it is correct to replace them.
* docs: typo: "exists and executable" -> "exists and is executable"
---------
Co-authored-by: Andrew-Zipperer <atzipperer@gmail.com>
Free-threaded builds can intermittently tickle a longstanding bug (24 years!)
in the implementation of `threading.Condition`, leading to flakiness in the
test suite. Fixing the underlying issue will require more discussion, and will
likely apply to most of the concurrency primitives in the `threading` module
that are written in Python. See gh-118433 for more details.