They are alternate constructors which only accept numbers
(including objects with special methods __float__, __complex__
and __index__), but not strings.
It is our general practice to make new optional parameters keyword-only,
even if the existing parameters are all positional-or-keyword. Passing
this parameter as positional would look confusing and could be error-prone
if additional parameters are added in the future.
Performance improvement to `float.fromhex`: use a lookup table
for computing the hexadecimal value of a character, in place of the
previous switch-case construct. Patch by Bruno Lima.
On POSIX systems, excluding macOS framework installs, the lib directory
for the free-threaded build now includes a "t" suffix to avoid conflicts
with a co-located default build installation.
When builtin static types are initialized for a subinterpreter, various "tp" slots have already been inherited (for the main interpreter). This was interfering with the logic in add_operators() (in Objects/typeobject.c), causing a wrapper to get created when it shouldn't. This change fixes that by preserving the original data from the static type struct and checking that.
The `_PySeqLock_EndRead` function needs an acquire fence to ensure that
the load of the sequence happens after any loads within the read side
critical section. The missing fence can trigger bugs on macOS arm64.
Additionally, we need a release fence in `_PySeqLock_LockWrite` to
ensure that the sequence update is visible before any modifications to
the cache entry.
Make error message for index() methods consistent
Remove the repr of the searched value (which can be arbitrary large)
from ValueError messages for list.index(), range.index(), deque.index(),
deque.remove() and ShareableList.index(). Make the error messages
consistent with error messages for other index() and remove()
methods.
This reduces the system call count of a simple program[0] that reads all
the `.rst` files in Doc by over 10% (5706 -> 4734 system calls on my
linux system, 5813 -> 4875 on my macOS)
This reduces the number of `fstat()` calls always and seek calls most
the time. Stat was always called twice, once at open (to error early on
directories), and a second time to get the size of the file to be able
to read the whole file in one read. Now the size is cached with the
first call.
The code keeps an optimization that if the user had previously read a
lot of data, the current position is subtracted from the number of bytes
to read. That is somewhat expensive so only do it on larger files,
otherwise just try and read the extra bytes and resize the PyBytes as
needeed.
I built a little test program to validate the behavior + assumptions
around relative costs and then ran it under `strace` to get a log of the
system calls. Full samples below[1].
After the changes, this is everything in one `filename.read_text()`:
```python3
openat(AT_FDCWD, "cpython/Doc/howto/clinic.rst", O_RDONLY|O_CLOEXEC) = 3`
fstat(3, {st_mode=S_IFREG|0644, st_size=343, ...}) = 0`
ioctl(3, TCGETS, 0x7ffdfac04b40) = -1 ENOTTY (Inappropriate ioctl for device)
lseek(3, 0, SEEK_CUR) = 0
read(3, ":orphan:\n\n.. This page is retain"..., 344) = 343
read(3, "", 1) = 0
close(3) = 0
```
This does make some tradeoffs
1. If the file size changes between open() and readall(), this will
still get all the data but might have more read calls.
2. I experimented with avoiding the stat + cached result for small files
in general, but on my dev workstation at least that tended to reduce
performance compared to using the fstat().
[0]
```python3
from pathlib import Path
nlines = []
for filename in Path("cpython/Doc").glob("**/*.rst"):
nlines.append(len(filename.read_text()))
```
[1]
Before small file:
```
openat(AT_FDCWD, "cpython/Doc/howto/clinic.rst", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=343, ...}) = 0
ioctl(3, TCGETS, 0x7ffe52525930) = -1 ENOTTY (Inappropriate ioctl for device)
lseek(3, 0, SEEK_CUR) = 0
lseek(3, 0, SEEK_CUR) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=343, ...}) = 0
read(3, ":orphan:\n\n.. This page is retain"..., 344) = 343
read(3, "", 1) = 0
close(3) = 0
```
After small file:
```
openat(AT_FDCWD, "cpython/Doc/howto/clinic.rst", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=343, ...}) = 0
ioctl(3, TCGETS, 0x7ffdfac04b40) = -1 ENOTTY (Inappropriate ioctl for device)
lseek(3, 0, SEEK_CUR) = 0
read(3, ":orphan:\n\n.. This page is retain"..., 344) = 343
read(3, "", 1) = 0
close(3) = 0
```
Before large file:
```
openat(AT_FDCWD, "cpython/Doc/c-api/typeobj.rst", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=133104, ...}) = 0
ioctl(3, TCGETS, 0x7ffe52525930) = -1 ENOTTY (Inappropriate ioctl for device)
lseek(3, 0, SEEK_CUR) = 0
lseek(3, 0, SEEK_CUR) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=133104, ...}) = 0
read(3, ".. highlight:: c\n\n.. _type-struc"..., 133105) = 133104
read(3, "", 1) = 0
close(3) = 0
```
After large file:
```
openat(AT_FDCWD, "cpython/Doc/c-api/typeobj.rst", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=133104, ...}) = 0
ioctl(3, TCGETS, 0x7ffdfac04b40) = -1 ENOTTY (Inappropriate ioctl for device)
lseek(3, 0, SEEK_CUR) = 0
lseek(3, 0, SEEK_CUR) = 0
read(3, ".. highlight:: c\n\n.. _type-struc"..., 133105) = 133104
read(3, "", 1) = 0
close(3) = 0
```
Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
As noted in gh-117983, the import importlib.util can be triggered at
interpreter startup under some circumstances, so adding threading makes
it a potentially obligatory load.
Lazy loading is not used in the stdlib, so this removes an unnecessary
load for the majority of users and slightly increases the cost of the
first lazily loaded module.
An obligatory threading load breaks gevent, which monkeypatches the
stdlib. Although unsupported, there doesn't seem to be an offsetting
benefit to breaking their use case.
For reference, here are benchmarks for the current main branch:
```
❯ hyperfine -w 8 './python -c "import importlib.util"'
Benchmark 1: ./python -c "import importlib.util"
Time (mean ± σ): 9.7 ms ± 0.7 ms [User: 7.7 ms, System: 1.8 ms]
Range (min … max): 8.4 ms … 13.1 ms 313 runs
```
And with this patch:
```
❯ hyperfine -w 8 './python -c "import importlib.util"'
Benchmark 1: ./python -c "import importlib.util"
Time (mean ± σ): 8.4 ms ± 0.7 ms [User: 6.8 ms, System: 1.4 ms]
Range (min … max): 7.2 ms … 11.7 ms 352 runs
```
Compare to:
```
❯ hyperfine -w 8 './python -c pass'
Benchmark 1: ./python -c pass
Time (mean ± σ): 7.6 ms ± 0.6 ms [User: 5.9 ms, System: 1.6 ms]
Range (min … max): 6.7 ms … 11.3 ms 390 runs
```
This roughly halves the import time of importlib.util.
This amends 6988ff02a5: memory allocation for
stginfo->ffi_type_pointer.elements in PyCSimpleType_init() should be
more generic (perhaps someday fmt->pffi_type->elements will be not a
two-elements array).
It should finally resolve#61103.
Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
When creating the JUnit XML file, regrtest now escapes characters
which are invalid in XML, such as the chr(27) control character used
in ANSI escape sequences.
1. Use pkg-config to check for ncursesw/panelw. If that fails, use
pkg-config to check for ncurses/panel.
2. Regardless of pkg-config output, search for curses/panel headers, so
we're sure we have all defines in pyconfig.h.
3. Regardless of pkg-config output, check if libncurses or libncursesw
contains the 'initscr' symbol; if it does _and_ pkg-config failed
earlier, add the resulting -llib linker option to CURSES_LIBS.
Ditto for 'update_panels' and PANEL_LIBS.
4. Wrap the rest of the checks with WITH_SAVE_ENV and make sure we're
using updated LIBS and CPPFLAGS for those.
Add the PY_CHECK_CURSES convenience macro.
asyncio earlier relied on subprocess module to send signals to the process, this has some drawbacks one being that subprocess module unnecessarily calls waitpid on child processes and hence it races with asyncio implementation which internally uses child watchers. To mitigate this, now asyncio sends signals directly to the process without going through the subprocess on non windows systems. On Windows it fallbacks to subprocess module handling but on windows there are no child watchers so this issue doesn't exists altogether.
In some cases, previously computed as (nan+nanj), we could
recover meaningful component values in the result, see
e.g. the C11, Annex G.5.2, routine _Cdivd().
* parse_intermixed_args() now raises ArgumentError instead of calling
error() if exit_on_error is false.
* Internal code now always raises ArgumentError instead of calling
error(). It is then caught at the higher level and error() is called if
exit_on_error is true.
The check for whether the log file is a real file is expensive on NFS
filesystems. This commit reorders the rollover condition checking to
not do the file type check if the expected file size is less than the
rotation threshold.
Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>
This change makes things a little less painful for some users. It also fixes a failing assert (gh-120765), by making sure all subinterpreters are destroyed before the main interpreter. As part of that, we make sure Py_Finalize() always runs with the main interpreter active.
This PR sets up tagged pointers for CPython.
The general idea is to create a separate struct _PyStackRef for everything on the evaluation stack to store the bits. This forces the C compiler to warn us if we try to cast things or pull things out of the struct directly.
Only for free threading: We tag the low bit if something is deferred - that means we skip incref and decref operations on it. This behavior may change in the future if Mark's plans to defer all objects in the interpreter loop pans out.
This implies a strict stack reference discipline is required. ALL incref and decref operations on stackrefs must use the stackref variants. It is unsafe to untag something then do normal incref/decref ops on it.
The new incref and decref variants are called dup and close. They mimic a "handle" API operating on these stackrefs.
Please read Include/internal/pycore_stackref.h for more information!
---------
Co-authored-by: Mark Shannon <9448417+markshannon@users.noreply.github.com>
PyDict_Next no longer locks the dictionary in the free-threaded build. Locking
around individual PyDict_Next calls is not sufficient because the function
returns borrowed references and because it allows concurrent modifications
during the iteraiton loop.
The internal locking also interferes with correct external synchronization
because it may suspend outer critical sections created by the caller.
PyUnicode_FromFormat() no longer produces the ending \ufffd
character for truncated C string when use precision with %s and %V.
It now truncates the string before the start of truncated multibyte sequences.
The integer part of the timestamp can be rounded up, while the millisecond
calculation truncates, causing the log timestamp to be wrong by up to 999 ms
(affected roughly 1 in 8 million timestamps).
Add `pathlib.Path.copytree()` method, which recursively copies one
directory to another.
This differs from `shutil.copytree()` in the following respects:
1. Our method has a *follow_symlinks* argument, whereas shutil's has a
*symlinks* argument with an inverted meaning.
2. Our method lacks something like a *copy_function* argument. It always
uses `Path.copy()` to copy files.
3. Our method lacks something like a *ignore_dangling_symlinks* argument.
Instead, users can filter out danging symlinks with *ignore*, or
ignore exceptions with *on_error*
4. Our *ignore* argument is a callable that accepts a single path object,
whereas shutil's accepts a path and a list of child filenames.
5. We add an *on_error* argument, which is a callable that accepts
an `OSError` instance. (`Path.walk()` also accepts such a callable).
Co-authored-by: Nice Zombies <nineteendo19d0@gmail.com>
This makes the following macros public as part of the non-limited C-API for
locking a single object or two objects at once.
* `Py_BEGIN_CRITICAL_SECTION(op)` / `Py_END_CRITICAL_SECTION()`
* `Py_BEGIN_CRITICAL_SECTION2(a, b)` / `Py_END_CRITICAL_SECTION2()`
The supporting functions and structs used by the macros are also exposed for
cases where C macros are not available.
* Add an InternalDocs file describing how interning should work and how to use it.
* Add internal functions to *explicitly* request what kind of interning is done:
- `_PyUnicode_InternMortal`
- `_PyUnicode_InternImmortal`
- `_PyUnicode_InternStatic`
* Switch uses of `PyUnicode_InternInPlace` to those.
* Disallow using `_Py_SetImmortal` on strings directly.
You should use `_PyUnicode_InternImmortal` instead:
- Strings should be interned before immortalization, otherwise you're possibly
interning a immortalizing copy.
- `_Py_SetImmortal` doesn't handle the `SSTATE_INTERNED_MORTAL` to
`SSTATE_INTERNED_IMMORTAL` update, and those flags can't be changed in
backports, as they are now part of public API and version-specific ABI.
* Add private `_only_immortal` argument for `sys.getunicodeinternedsize`, used in refleak test machinery.
* Make sure the statically allocated string singletons are unique. This means these sets are now disjoint:
- `_Py_ID`
- `_Py_STR` (including the empty string)
- one-character latin-1 singletons
Now, when you intern a singleton, that exact singleton will be interned.
* Add a `_Py_LATIN1_CHR` macro, use it instead of `_Py_ID`/`_Py_STR` for one-character latin-1 singletons everywhere (including Clinic).
* Intern `_Py_STR` singletons at startup.
* For free-threaded builds, intern `_Py_LATIN1_CHR` singletons at startup.
* Beef up the tests. Cover internal details (marked with `@cpython_only`).
* Add lots of assertions
Co-Authored-By: Eric Snow <ericsnowcurrently@gmail.com>
Rodrigo Girão Serrão
Serhiy Storchaka
Dominic H
Jelle Zijlstra
Samuel Thibault
Bruno Lima
Gregor
Pablo Galindo Salgado
Marta Gómez Macías
Bas Bloemsaat
Zachary Ware
Savannah Ostrowski
Sam Gross
Eric Snow
Tian Gao
Victor Stinner
satori1995
Hugo van Kemenade
Marc Mueller
Barney Gale
Mark Shannon
Shantanu
Sergey B Kirpichev
Nice Zombies
Cody Maloney
Bénédikt Tran
Chris Markiewicz
Stefano Rivera
Diego Russo
Brandt Bucher
Will Childs-Klein
Erlend E. Aasland
Kumar Aditya
Kirill Podoprigora
Russell Keith-Magee
Wim Jeantine-Glenn
blhsing
Steve Dower
Craig Robson
Nadeshiko Manju
Pradyun Gedam
Janek Nouvertné
Ken Jin
Nate Ohlson
Alex Waygood
Michael Allwright
Jason R. Coombs
Peter
neonene
Petr Viktorin
Nikita Sobolev
Irit Katriel
Xarblu