* gh-71936: Fix race condition in multiprocessing.Pool
Proxes of shared objects register a Finalizer in BaseProxy._incref(), and it
will call BaseProxy._decref() when it is GCed. This may cause a race condition
with Pool(maxtasksperchild=None) on Windows.
A connection would be closed and raised TypeError when a GC occurs between
_ConnectionBase._check_writable() and _ConnectionBase._send_bytes() in
_ConnectionBase.send() in the second or later task, and a new object
is allocated that shares the id() of a previously deleted one.
Instead of using the id() of the token (or the proxy), use a unique,
non-reusable number.
Co-Authored-By: Akinori Hattori <hattya@gmail.com>
Previously, this would cause an `AttributeError` if the patch stopped more than once after this, and would also disrupt the original patched object.
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Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
The PyMutex implementation supports unlocking after fork because we
clear the list of waiters in parking_lot.c. This doesn't work as well
for _PyRecursiveMutex because on some systems, such as SerenityOS, the
thread id is not preserved across fork().
Accepting objects with false values (like 0 and []) except empty strings
and byte-like objects and None in urllib.parse functions parse_qsl() and
parse_qs() is now deprecated.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
* Removes erroneous explanation of the `global` statement restrictions; a name declared as global can be subsequently bound using any kind of name binding operation.
* Updates `test_global.py` to also test various name-binding scenarios for global
variables to ensure correct behavior
When `zipfile.Path.open` is called, the implementation will check
whether the path already exists in the ZIP file. However, this check is
only required when the ZIP file is in read mode. By swapping arguments
of the `and` operator, the short-circuiting will prevent the check from
being run in write mode.
This change will improve the performance of `open()`, because checking
whether a file exists is slow in write mode, especially when the archive
has many members.
gh-117378: Fix multiprocessing forkserver preload sys.path inheritance.
`sys.path` was not properly being sent from the parent process when launching
the multiprocessing forkserver process to preload imports. This bug has been
there since the forkserver start method was introduced in Python 3.4. It was
always _supposed_ to inherit `sys.path` the same way the spawn method does.
Observable behavior change: A `''` value in `sys.path` will now be replaced in
the forkserver's `sys.path` with an absolute pathname
`os.path.abspath(os.getcwd())` saved at the time that `multiprocessing` was
imported in the parent process as it already was when using the spawn start
method. **This will only be observable during forkserver preload imports**.
The code invoked before calling things in another process already correctly sets `sys.path`.
Which is likely why this went unnoticed for so long as a mere performance issue in
some configurations.
A workaround for the bug on impacted Pythons is to set PYTHONPATH in the
environment before multiprocessing's forkserver process was started. Not perfect
as that is then inherited by other children, etc, but likely good enough for many
people's purposes.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Add emscripten.py script to automate emscripten build.
This is modeled heavily on `Tools/wasm/wasi.py`. This will form the basis of an Emscripten build bot.
Adjust `urllib.request.pathname2url()` and `url2pathname()` so that they
don't remove slashes from Windows DOS drive paths and URLs. There was no
basis for this behaviour, and it conflicts with how UNC and POSIX paths are
handled.
Eventually wasm32-wasi will represent WASI 1.0, and so it's currently deprecated so it can be used for that eventual purpose. wasm32-wasip1 is also more specific to what version of WASI is currently supported.
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Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
Replace the os.environ.refresh() method with a new
os.reload_environ() function.
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
The implementation of `Path.glob()` does rather a hacky thing: it calls
`self.with_segments()` to convert the given pattern to a `Path` object, and
then peeks at the private `_raw_path` attribute to see if pathlib removed a
trailing slash from the pattern.
In this patch, we make `glob()` use a new `_parse_pattern()` classmethod
that splits the pattern into parts while preserving information about any
trailing slash. This skips the cost of creating a `Path` object, and avoids
some path anchor normalization, which makes `Path.glob()` slightly faster.
But mostly it's about making the code less naughty.
Co-authored-by: Tomas R. <tomas.roun8@gmail.com>
Ritvik Pasham
Petr Viktorin
Red4Ru
Andrew Svetlov
Nice Zombies
Sam Gross
Barney Gale
Serhiy Storchaka
Bénédikt Tran
Stephen Morton
RUANG (James Roy)
Sayandip Dutta
Daehee Kim
Stephen Morton
Sahil Prajapati
Diego Russo
Beomsoo Kim
Ned Batchelder
Hugo van Kemenade
sobolevn
Gregory P. Smith
Jan Hicken
Hood Chatham
Steve Dower
Xuanteng Huang
Brett Cannon
Mark Shannon
Duprat
blhsing
Peter Bierma
Victor Stinner
Erlend E. Aasland
Kumar Aditya