Add Python implementations of certain longobject.c functions. These use
asymptotically faster algorithms that can be used for operations on
integers with many digits. In those cases, the performance overhead of
the Python implementation is not significant since the asymptotic
behavior is what dominates runtime. Functions provided by this module
should be considered private and not part of any public API.
Co-author: Tim Peters <tim.peters@gmail.com>
Co-author: Mark Dickinson <dickinsm@gmail.com>
Co-author: Bjorn Martinsson
Functions re.sub() and re.subn() and corresponding re.Pattern methods
are now 2-3 times faster for replacement strings containing group references.
Closes#91524
Primarily authored by serhiy-storchaka Serhiy Storchaka
Minor-cleanups-by: Gregory P. Smith [Google] <greg@krypto.org>
On Windows, when the Python test suite is run with the -jN option,
the ANSI code page is now used as the encoding for the stdout
temporary file, rather than using UTF-8 which can lead to decoding
errors.
Linux abstract sockets are insecure as they lack any form of filesystem
permissions so their use allows anyone on the system to inject code into
the process.
This removes the default preference for abstract sockets in
multiprocessing introduced in Python 3.9+ via
https://github.com/python/cpython/pull/18866 while fixing
https://github.com/python/cpython/issues/84031.
Explicit use of an abstract socket by a user now generates a
RuntimeWarning. If we choose to keep this warning, it should be
backported to the 3.7 and 3.8 branches.
* The compiler analyzes the usage of the first 64 local variables all at once using bit masks.
* Local variables beyond the first 64 are only partially analyzed, achieving linear time.
Added os.setns and os.unshare to easily switch between namespaces
on Linux.
Co-authored-by: Christian Heimes <christian@python.org>
Co-authored-by: CAM Gerlach <CAM.Gerlach@Gerlach.CAM>
Co-authored-by: Victor Stinner <vstinner@python.org>
Make sys.setprofile() and sys.settrace() functions reentrant. They
can no long fail with: RuntimeError("Cannot install a trace function
while another trace function is being installed").
Make _PyEval_SetTrace() and _PyEval_SetProfile() functions reentrant,
rather than detecting and rejecting reentrant calls. Only delete the
reference to function arguments once the new function is fully set,
when a reentrant call is safe. Call also _PySys_Audit() earlier.
The os module and the PyUnicode_FSDecoder() function no longer accept
bytes-like paths, like bytearray and memoryview types: only the exact
bytes type is accepted for bytes strings.
Change summary:
+ There is now a `gzip.READ_BUFFER_SIZE` constant that is 128KB. Other programs that read in 128KB chunks: pigz and cat. So this seems best practice among good programs. Also it is faster than 8 kb chunks.
+ a zlib._ZlibDecompressor was added. This is the _bz2.BZ2Decompressor ported to zlib. Since the zlib.Decompress object is better for in-memory decompression, the _ZlibDecompressor is hidden. It only makes sense in file decompression, and that is already implemented now in the gzip library. No need to bother the users with this.
+ The ZlibDecompressor uses the older Cpython arrange_output_buffer functions, as those are faster and more appropriate for the use case.
+ GzipFile.read has been optimized. There is no longer a `unconsumed_tail` member to write back to padded file. This is instead handled by the ZlibDecompressor itself, which has an internal buffer. `_add_read_data` has been inlined, as it was just two calls.
EDIT: While I am adding improvements anyway, I figured I could add another one-liner optimization now to the python -m gzip application. That read chunks in io.DEFAULT_BUFFER_SIZE previously, but has been updated now to use READ_BUFFER_SIZE chunks.
#97530 fixed IDLE tests possibly crashing on a Mac without a GUI.
But it resulted in IDLE not starting in 3.10.8, 3.12.0a1, and
Microsoft Python 3.10.2288.0 when test/* is not installed.
After this patch, test.* is only imported when testing on Mac.
This is the next step for deprecating child watchers.
Until we've removed the API completely we have to use it, so this PR is mostly suppressing a lot of warnings when using the API internally.
Once the child watcher API is totally removed, the two child watcher implementations we actually use and need (Pidfd and Thread) will be turned into internal helpers.
On macOS, fix a crash in syslog.syslog() in multi-threaded
applications. On macOS, the libc syslog() function is not
thread-safe, so syslog.syslog() no longer releases the GIL to call
it.
This seems pretty straightforward. The issue mentions other calls in mmapmodule that we could release the GIL on, but those are in methods where we'd need to be careful to ensure that something sensible happens if those are called concurrently. In prior art, note that #12073 released the GIL for munmap. In a toy benchmark, I see the speedup you'd expect from doing this.
Automerge-Triggered-By: GH:gvanrossum
* gh-96821: Fix undefined behaviour in `audioop.c`
Left-shifting negative numbers is undefined behaviour.
Fortunately, multiplication works just as well, is defined behaviour,
and gets compiled to the same machine code as before by optimizing
compilers.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Neil Schemenauer
Stanley
Pablo Galindo Salgado
Erlend E. Aasland
Matthew Rahtz
James Gerity
Thomas Wouters
Kumar Aditya
Serhiy Storchaka
Ikko Ashimine
Victor Stinner
Carl Meyer
Gregory P. Smith
Dennis Sweeney
Ben Kallus
Irit Katriel
Steve Dower
Noam Cohen
Dong-hee Na
chgnrdv
Hugo van Kemenade
Jack Hindmarch
Paul Moore
Raymond Hettinger
Ruben Vorderman
Jason R. Coombs
Joannah Nanjekye
Terry Jan Reedy
Vinay Sajip
Jakub Kuczys
Tony Solomonik
Christoph Hamsen
Julien Palard
Ken Jin
Shantanu
Matthias Görgens