* 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.
---------
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
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
The first version had it running two forkserver and one spawn tests underneath each of the _fork, _forkserver, and _spawn test suites that build off the generic one.
This adds to the existing complexity of the multiprocessing test suite by offering BaseTestCase classes another attribute to control which suites they are invoked under. Practicality vs purity here. :/
Net result: we don't over-run the new test and their internal logic is simplified.
Skip `testMakefileCloseSocketDestroy` test if `sys.getrefcount` isn't available. This is necessary for PyPy and other Python implementations that do not have `sys.getrefcount`.
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>
In `PathBase.resolve()`, raise `UnsupportedOperation` if a non-POSIX path
parser is used (our implementation uses `posixpath._realpath()`, which
produces incorrect results for non-POSIX path flavours.) Also tweak code to
call `self.absolute()` upfront rather than supplying an emulated `getcwd()`
function.
Adjust `PathBase.absolute()` to work somewhat like `resolve()`. If a POSIX
path parser is used, we treat the root directory as the current directory.
This is the simplest useful behaviour for concrete path types without a
current directory cursor.
In the past I've equivocated about whether to require at least one argument
in the `PurePathBase` (and `PathBase`) initializer, and what the default
should be if we make it optional. I now have a local use case that has
persuaded me to make it optional and default to the empty string (a
`zipp.Path`-like class that treats relative and absolute paths similarly.)
Happily this brings the base class more in line with `PurePath` and `Path`.
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.
Move creation of a tuple for var-positional parameter out of
_PyArg_UnpackKeywordsWithVararg().
Merge _PyArg_UnpackKeywordsWithVararg() with _PyArg_UnpackKeywords().
Add a new parameter in _PyArg_UnpackKeywords().
The "parameters" and "converters" attributes of ParseArgsCodeGen no
longer contain the var-positional parameter. It is now available as the
"varpos" attribute. Optimize code generation for var-positional
parameter and reuse the same generating code for functions with and without
keyword parameters.
Add special converters for var-positional parameter. "tuple" represents it as
a Python tuple and "array" represents it as a continuous array of PyObject*.
"object" is a temporary alias of "tuple".
* gh-126298: Don't deduplicated slice constants based on equality
* NULL check for PySlice_New
* Fix refcounting
* Fix refcounting some more
* Fix refcounting
* Make tests more complete
* Fix tests
If `read()` in the ConnectionHandler thread raises `OSError` (except `ConnectionError`),
the ConnectionHandler shuts down the entire ThreadedEchoServer,
preventing further connections.
It also does that for `EPROTOTYPE` in `wrap_conn`.
As far as I can see, this is done to avoid the server thread getting stuck,
forgotten, in its accept loop. However, since 2011 (5b95eb90a7)
the server is used as a context manager, and its `__exit__` does `stop()` and `join()`.
(I'm not sure if we *always* used `with` since that commit, but currently we do.)
Make sure that the context manager *is* used, and remove the `server.stop()`
calls from ConnectionHandler.
The skipping machinery called `getattr(err, "reason", "")` on an arbitrary
exception. As intermittent Buildbot failures show, sometimes it's set
to None.
Convert it to string for this specific check.
- The specialization logic determines the appropriate specialization using only the operand's type, which is safe to read non-atomically (changing it requires stopping the world). We are guaranteed that the type will not change in between when it is checked and when we specialize the bytecode because the types involved are immutable (you cannot assign to `__class__` for exact instances of `dict`, `set`, or `frozenset`). The bytecode is mutated atomically using helpers.
- The specialized instructions rely on the operand type not changing in between the `DEOPT_IF` checks and the calls to the appropriate type-specific helpers (e.g. `_PySet_Contains`). This is a correctness requirement in the default builds and there are no changes to the opcodes in the free-threaded builds that would invalidate this.
