"Generally, mixed-mode arithmetic combining real and complex variables should
be performed directly, not by first coercing the real to complex, lest the sign
of zero be rendered uninformative; the same goes for combinations of pure
imaginary quantities with complex variables." (c) Kahan, W: Branch cuts for
complex elementary functions.
This patch implements mixed-mode arithmetic rules, combining real and
complex variables as specified by C standards since C99 (in particular,
there is no special version for the true division with real lhs
operand). Most C compilers implementing C99+ Annex G have only these
special rules (without support for imaginary type, which is going to be
deprecated in C2y).
When handed an absolute Windows path such as `C:\foo` or `//server/share`,
the `urllib.request.pathname2url()` function returns a URL with an
authority section, such as `///C:/foo` or `//server/share` (or before
GH-126205, `////server/share`). Only the `file:` prefix is omitted.
But when handed an absolute POSIX path such as `/etc/hosts`, or a Windows
path of the same form (rooted but lacking a drive), the function returns a
URL without an authority section, such as `/etc/hosts`.
This patch corrects the discrepancy by adding a `//` prefix before
drive-less, rooted paths when generating URLs.
Stop converting Windows drive letters to uppercase in
`urllib.request.pathname2url()` and `url2pathname()`. This behaviour is
unnecessary and inconsistent with pathlib's file URI implementation.
If Python fails to start newly created thread
due to failure of underlying PyThread_start_new_thread() call,
its state should be removed from interpreter' thread states list
to avoid its double cleanup.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Threads are gone after fork, so clear the queues too. Otherwise the
child process (here created via multiprocessing.Process) crashes on
interpreter exit.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
* Name without a PATHEXT extension is only searched if the mode does not
include X_OK.
* Support multi-component PATHEXT extensions (e.g. ".foo.bar").
* Support files without extensions in PATHEXT contains dot-only extension
(".", "..", etc).
* Support PATHEXT extensions that end with a dot (e.g. ".foo.").
The usage parameter of argparse.ArgumentParser no longer
affects the default value of the prog parameter in subparsers.
Previously the full custom usage of the main parser was used as
the prog prefix in subparsers.
`mmap`, `munmap`, and `mprotect` are used by CPython for memory
management, which may occur in the middle of the FileIO tests. The
system calls can also be used with files, so `strace` includes them
in its `%file` and `%desc` filters.
Filter out the `mmap` system calls related to memory allocation for the
file tests. Currently FileIO doesn't do `mmap` at all, so didn't add
code to track from `mmap` through `munmap` since it wouldn't be used.
For now if an `mmap` on a fd happens, the call will be included (which
may cause test to fail), and at that time support for tracking the
address throug `munmap` could be added.
The `methodcaller` C vectorcall implementation uses an arguments array
that is shared across calls. The first argument is modified on every
invocation. This isn't thread-safe in the free threading build. I think
it's also not safe in general, but for now just disable it in the free
threading build.
Decode a file URI like `file://///server/share` as a UNC path like
`\\server\share`. This form of file URI is created by software the simply
prepends `file:///` to any absolute Windows path.
Discard any 'localhost' authority from the beginning of a `file:` URI. As a
result, file URIs like `//localhost/etc/hosts` are correctly decoded as
`/etc/hosts`.
Adjust `pathname2url()` to encode embedded colon characters in Windows
paths, rather than bailing out with an `OSError`.
Co-authored-by: Steve Dower <steve.dower@microsoft.com>
* Fix support of STRING and GLOBAL opcodes with non-ASCII arguments.
* dis() now outputs non-ASCII bytes in STRING, BINSTRING and
SHORT_BINSTRING arguments as escaped (\xXX).
Distribution tooling (ex. sandbox on Gentoo and fakeroot on Debian) uses
LD_PRELOAD to intercept system calls and potentially modify them when
building. These tools can change the set of system calls, so disable
system call testing under these cases.
Co-authored-by: Michał Górny <mgorny@gentoo.org>
This adds authentication to the forkserver control socket. In the past only filesystem permissions protected this socket from code injection into the forkserver process by limiting access to the same UID, which didn't exist when Linux abstract namespace sockets were used (see issue) meaning that any process in the same system network namespace could inject code. We've since stopped using abstract namespace sockets by default, but protecting our control sockets regardless of type is a good idea.
This reuses the HMAC based shared key auth already used by `multiprocessing.connection` sockets for other purposes.
Doing this is useful so that filesystem permissions are not relied upon and trust isn't implied by default between all processes running as the same UID with access to the unix socket.
### pyperformance benchmarks
No significant changes. Including `concurrent_imap` which exercises `multiprocessing.Pool.imap` in that suite.
### Microbenchmarks
This does _slightly_ slow down forkserver use. How much so appears to depend on the platform. Modern platforms and simple platforms are less impacted. This PR adds additional IPC round trips to the control socket to tell forkserver to spawn a new process. Systems with potentially high latency IPC are naturally impacted more.
Typically a 1-4% slowdown on a very targeted process creation microbenchmark, with a worst case overloaded system slowdown of 20%. No evidence that these slowdowns appear in practical sense. See the PR for details.
Adjust `urllib.request.url2pathname()` and `pathname2url()` to use the
filesystem encoding when quoting and unquoting file URIs, rather than
forcing use of UTF-8.
No changes are needed in the `nturl2path` module because Windows always
uses UTF-8, per PEP 529.
