gh-117983: Defer import of threading for lazy module loading (GH-120233)
As noted in gh-117983, the import importlib.util can be triggered at
interpreter startup under some circumstances, so adding threading makes
it a potentially obligatory load.
Lazy loading is not used in the stdlib, so this removes an unnecessary
load for the majority of users and slightly increases the cost of the
first lazily loaded module.
An obligatory threading load breaks gevent, which monkeypatches the
stdlib. Although unsupported, there doesn't seem to be an offsetting
benefit to breaking their use case.
For reference, here are benchmarks for the current main branch:
```
❯ hyperfine -w 8 './python -c "import importlib.util"'
Benchmark 1: ./python -c "import importlib.util"
Time (mean ± σ): 9.7 ms ± 0.7 ms [User: 7.7 ms, System: 1.8 ms]
Range (min … max): 8.4 ms … 13.1 ms 313 runs
```
And with this patch:
```
❯ hyperfine -w 8 './python -c "import importlib.util"'
Benchmark 1: ./python -c "import importlib.util"
Time (mean ± σ): 8.4 ms ± 0.7 ms [User: 6.8 ms, System: 1.4 ms]
Range (min … max): 7.2 ms … 11.7 ms 352 runs
```
Compare to:
```
❯ hyperfine -w 8 './python -c pass'
Benchmark 1: ./python -c pass
Time (mean ± σ): 7.6 ms ± 0.6 ms [User: 5.9 ms, System: 1.6 ms]
Range (min … max): 6.7 ms … 11.3 ms 390 runs
```
This roughly halves the import time of importlib.util.
(cherry picked from commit 94f50f8ee6)
Co-authored-by: Chris Markiewicz <effigies@gmail.com>
* Make MetadataPathFinder a proper classmethod.
* In PathFinder.invalidate_caches, also invoke MetadataPathFinder.invalidate_caches.
* Add blurb
(cherry picked from commit 5f52d20a93)
gh-114763: Protect lazy loading modules from attribute access races (GH-114781)
Setting the __class__ attribute of a lazy-loading module to ModuleType enables other threads to attempt to access attributes before the loading is complete. Now that is protected by a lock.
(cherry picked from commit 200271c61d)
Co-authored-by: Chris Markiewicz <effigies@gmail.com>
gh-112983: Add the known magic value of 3495 for Python 3.11 bytecode (GH-112985)
Add the known magic value of 3495 for Python 3.11 bytecode
(cherry picked from commit 616622cab7)
Co-authored-by: wim glenn <jump@wimglenn.com>
gh-112414: Fix `AttributeError` when calling `repr()` on a namespace package imported with a custom loader (GH-112425)
(cherry picked from commit 0622839cfe)
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
The original name wasn't as clear as it could have been. This change includes the following:
* rename the function
* change the default value for "disable_check" to False
* add clues to the docstring that folks should probably not use the function
---------
(cherry picked from commit 34c63b86d3)
Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
Co-authored-by: Kirill Podoprigora <kirill.bast9@mail.ru>
This implements PEP 695, Type Parameter Syntax. It adds support for:
- Generic functions (def func[T](): ...)
- Generic classes (class X[T](): ...)
- Type aliases (type X = ...)
- New scoping when the new syntax is used within a class body
- Compiler and interpreter changes to support the new syntax and scoping rules
Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Co-authored-by: Eric Traut <eric@traut.com>
Co-authored-by: Larry Hastings <larry@hastings.org>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
* Remove deprecated classes from pkgutil
* Remove some other PEP 302 obsolescence
* Use find_spec instead of load_module
* Remove more tests of PEP 302 obsolete APIs
* Remove another bunch of tests using obsolete load_modules()
* Remove deleted names from __all__
* Remove obsolete footnote
* imp is removed
* Remove `imp` from generated stdlib names
* What's new and blurb
* Update zipimport documentation for the removed methods
* Fix some Windows tests
* Remove any test (or part of a test) that references `find_module()`.
* Use assertIsNone() / assertIsNotNone() consistently.
* Update Doc/reference/import.rst
* We don't need pkgutil._get_spec() any more either
* test.test_importlib.fixtures.NullFinder
* ...BadLoaderFinder.find_module
* ...test_api.InvalidatingNullFinder.find_module
* ...test.test_zipimport test of z.find_module
* Suppress cross-references to find_loader and find_module
* Suppress cross-references to Finder
* Suppress cross-references to pkgutil.ImpImporter and pkgutil.ImpLoader
---------
Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>
Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com>
This speeds up `super()` (by around 85%, for a simple one-level
`super().meth()` microbenchmark) by avoiding allocation of a new
single-use `super()` object on each use.
* The majority of the monitoring code is in instrumentation.c
* The new instrumentation bytecodes are in bytecodes.c
* legacy_tracing.c adapts the new API to the old sys.setrace and sys.setprofile APIs
Change FOR_ITER to have the same stack effect regardless of whether it branches or not.
Performance is unchanged as FOR_ITER (and specialized forms jump over the cleanup code).
