This runs test_asyncio sub-tests in parallel using sharding from Cinder. This suite is typically the longest-pole in runs because it is a test package with a lot of further sub-tests otherwise run serially. By breaking out the sub-tests as independent modules we can run a lot more in parallel.
After porting we can see the direct impact on a multicore system.
Without this change:
Running make test is 5 min 26 seconds
With this change:
Running make test takes 3 min 39 seconds
That'll vary based on system and parallelism. On a `-j 4` run similar to what CI and buildbot systems often do, it reduced the overall test suite completion latency by 10%.
The drawbacks are that this implementation is hacky and due to the sorting of the tests it obscures when the asyncio tests occur and involves changing CPython test infrastructure but, the wall time saved it is worth it, especially in low-core count CI runs as it pulls a long tail. The win for productivity and reserved CI resource usage is significant.
Future tests that deserve to be refactored into split up suites to benefit from are test_concurrent_futures and the way the _test_multiprocessing suite gets run for all start methods. As exposed by passing the -o flag to python -m test to get a list of the 10 longest running tests.
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Co-authored-by: Carl Meyer <carl@oddbird.net>
Co-authored-by: Gregory P. Smith <greg@krypto.org> [Google, LLC]
The default task name is "Task-<counter>" (if no name is passed in during Task creation).
This is initialized in `Task.__init__` (C impl) using string formatting, which can be quite slow.
Actually using the task name in real world code is not very common, so this is wasted init.
Let's defer this string formatting to the first time the name is read (in `get_name` impl),
so we don't need to pay the string formatting cost if the task name is never read.
We don't change the order in which tasks are assigned numbers (if they are) --
the number is set on task creation, as a PyLong instead of a formatted string.
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
subprocess's communicate(None) closes stdin of the child process, after
sending no (extra) data. Make asyncio variant do the same.
This fixes issues with processes that waits for EOF on stdin before
continuing.
Using `datetime.datetime.utcnow()` and `datetime.datetime.utcfromtimestamp()` will now raise a `DeprecationWarning`.
We also have removed our internal uses of these functions and documented the change.
This change removes the alias of the 'C' locale to 'en_US'. Because of
this alias, it is currently impossible for an application to use
setlocale() to specify a UTF-8 locale on a system that has no locales
installed, but which supports the C.UTF-8 locale/encoding.
gh-82814: Adds `errno.EACCES` to the list of ignored errors on
`_copyxattr`. EPERM and EACCES are different constants but
in general should be treated the same.
News entry authored by: Gregory P. Smith <greg@krypto.org>
This PR makes some minor linting adjustments to the Lib/test module
caught by [ruff](https://github.com/charliermarsh/ruff). The adjustments
are all related to the `F541 f-string without any placeholders` issue.
Issue: https://github.com/python/cpython/issues/103805
<!-- gh-issue-number: gh-103805 -->
* Issue: gh-103805
<!-- /gh-issue-number -->
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Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Gregory P. Smith <greg@krypto.org>
This is strictly about moving the "obmalloc" runtime state from
`_PyRuntimeState` to `PyInterpreterState`. Doing so improves isolation
between interpreters, specifically most of the memory (incl. objects)
allocated for each interpreter's use. This is important for a
per-interpreter GIL, but such isolation is valuable even without it.
FWIW, a per-interpreter obmalloc is the proverbial
canary-in-the-coalmine when it comes to the isolation of objects between
interpreters. Any object that leaks (unintentionally) to another
interpreter is highly likely to cause a crash (on debug builds at
least). That's a useful thing to know, relative to interpreter
isolation.
sockserver gains ForkingUnixStreamServer and ForkingUnixDatagramServer classes for consistency with all of the others. Ironically these existed but were buried in our test suite.
Addresses #103673
<!-- gh-issue-number: gh-103673 -->
* Issue: gh-103673
<!-- /gh-issue-number -->
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Co-authored-by: Gregory P. Smith <greg@krypto.org>
Co-authored-by: Nikita Sobolev <mail@sobolevn.me>
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.
* Clean up unused variables and imports in the email module
* Remove extra newline char
* Remove superflous dict+unpacking syntax
* Remove unused 'msg' var
* Clean up unused variables and imports in the email module
* Remove extra newline char
* Remove superflous dict+unpacking syntax
* Remove unused 'msg' var
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Co-authored-by: Barry Warsaw <barry@python.org>
The word 'dependent' is both an adjective and a noun. A 'dependant' is a British alternative spelling for the noun form. In idlelib.sidebar, 'OS-dependant' is an adjective and clearly wrong. In 'Using', 'dependant' as a noun would be acceptable in Britain, but we use American spellings in Python docs.
https://www.merriam-webster.com/words-at-play/spelling-variants-dependent-vs-dependant
