diff options
Diffstat (limited to 'Doc/howto')
| -rw-r--r-- | Doc/howto/free-threading-extensions.rst | 4 | ||||
| -rw-r--r-- | Doc/howto/free-threading-python.rst | 17 | ||||
| -rw-r--r-- | Doc/howto/perf_profiling.rst | 4 | ||||
| -rw-r--r-- | Doc/howto/regex.rst | 8 |
4 files changed, 20 insertions, 13 deletions
diff --git a/Doc/howto/free-threading-extensions.rst b/Doc/howto/free-threading-extensions.rst index 175bb5dc831..02b45879ccf 100644 --- a/Doc/howto/free-threading-extensions.rst +++ b/Doc/howto/free-threading-extensions.rst @@ -6,8 +6,8 @@ C API Extension Support for Free Threading ****************************************** -Starting with the 3.13 release, CPython has experimental support for running -with the :term:`global interpreter lock` (GIL) disabled in a configuration +Starting with the 3.13 release, CPython has support for running with +the :term:`global interpreter lock` (GIL) disabled in a configuration called :term:`free threading`. This document describes how to adapt C API extensions to support free threading. diff --git a/Doc/howto/free-threading-python.rst b/Doc/howto/free-threading-python.rst index c33cef2c8e9..24069617c47 100644 --- a/Doc/howto/free-threading-python.rst +++ b/Doc/howto/free-threading-python.rst @@ -1,18 +1,21 @@ .. _freethreading-python-howto: -********************************************** -Python experimental support for free threading -********************************************** +********************************* +Python support for free threading +********************************* -Starting with the 3.13 release, CPython has experimental support for a build of +Starting with the 3.13 release, CPython has support for a build of Python called :term:`free threading` where the :term:`global interpreter lock` (GIL) is disabled. Free-threaded execution allows for full utilization of the available processing power by running threads in parallel on available CPU cores. While not all software will benefit from this automatically, programs designed with threading in mind will run faster on multi-core hardware. -**The free-threaded mode is experimental** and work is ongoing to improve it: -expect some bugs and a substantial single-threaded performance hit. +The free-threaded mode is working and continues to be improved, but +there is some additional overhead in single-threaded workloads compared +to the regular build. Additionally, third-party packages, in particular ones +with an :term:`extension module`, may not be ready for use in a +free-threaded build, and will re-enable the :term:`GIL`. This document describes the implications of free threading for Python code. See :ref:`freethreading-extensions-howto` for information on @@ -43,7 +46,7 @@ Identifying free-threaded Python ================================ To check if the current interpreter supports free-threading, :option:`python -VV <-V>` -and :data:`sys.version` contain "experimental free-threading build". +and :data:`sys.version` contain "free-threading build". The new :func:`sys._is_gil_enabled` function can be used to check whether the GIL is actually disabled in the running process. diff --git a/Doc/howto/perf_profiling.rst b/Doc/howto/perf_profiling.rst index b579d776576..96d757ac452 100644 --- a/Doc/howto/perf_profiling.rst +++ b/Doc/howto/perf_profiling.rst @@ -92,7 +92,7 @@ Then we can use ``perf report`` to analyze the data: | | | | | | | |--51.67%--_PyEval_EvalFrameDefault | | | | | - | | | | |--11.52%--_PyLong_Add + | | | | |--11.52%--_PyCompactLong_Add | | | | | | | | | | | |--2.97%--_PyObject_Malloc ... @@ -142,7 +142,7 @@ Instead, if we run the same experiment with ``perf`` support enabled we get: | | | | | | | |--51.81%--_PyEval_EvalFrameDefault | | | | | - | | | | |--13.77%--_PyLong_Add + | | | | |--13.77%--_PyCompactLong_Add | | | | | | | | | | | |--3.26%--_PyObject_Malloc diff --git a/Doc/howto/regex.rst b/Doc/howto/regex.rst index e543f6d5657..7486a378dbb 100644 --- a/Doc/howto/regex.rst +++ b/Doc/howto/regex.rst @@ -1016,7 +1016,9 @@ extension. This regular expression matches ``foo.bar`` and Now, consider complicating the problem a bit; what if you want to match filenames where the extension is not ``bat``? Some incorrect attempts: -``.*[.][^b].*$`` The first attempt above tries to exclude ``bat`` by requiring +``.*[.][^b].*$`` + +The first attempt above tries to exclude ``bat`` by requiring that the first character of the extension is not a ``b``. This is wrong, because the pattern also doesn't match ``foo.bar``. @@ -1043,7 +1045,9 @@ confusing. A negative lookahead cuts through all this confusion: -``.*[.](?!bat$)[^.]*$`` The negative lookahead means: if the expression ``bat`` +``.*[.](?!bat$)[^.]*$`` + +The negative lookahead means: if the expression ``bat`` doesn't match at this point, try the rest of the pattern; if ``bat$`` does match, the whole pattern will fail. The trailing ``$`` is required to ensure that something like ``sample.batch``, where the extension only starts with |