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Diffstat (limited to 'Doc/library/concurrent.futures.rst')
| -rw-r--r-- | Doc/library/concurrent.futures.rst | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/Doc/library/concurrent.futures.rst b/Doc/library/concurrent.futures.rst index 8106cc2..10cffda 100644 --- a/Doc/library/concurrent.futures.rst +++ b/Doc/library/concurrent.futures.rst @@ -250,9 +250,10 @@ to a :class:`ProcessPoolExecutor` will result in deadlock. then :exc:`ValueError` will be raised. If *max_workers* is ``None``, then the default chosen will be at most ``61``, even if more processors are available. - *mp_context* can be a multiprocessing context or None. It will be used to - launch the workers. If *mp_context* is ``None`` or not given, the default - multiprocessing context is used. + *mp_context* can be a :mod:`multiprocessing` context or ``None``. It will be + used to launch the workers. If *mp_context* is ``None`` or not given, the + default :mod:`multiprocessing` context is used. + See :ref:`multiprocessing-start-methods`. *initializer* is an optional callable that is called at the start of each worker process; *initargs* is a tuple of arguments passed to the @@ -284,6 +285,13 @@ to a :class:`ProcessPoolExecutor` will result in deadlock. The *max_tasks_per_child* argument was added to allow users to control the lifetime of workers in the pool. + .. versionchanged:: 3.12 + The implicit use of the :mod:`multiprocessing` *fork* start method as a + platform default (see :ref:`multiprocessing-start-methods`) now raises a + :exc:`DeprecationWarning`. The default will change in Python 3.14. + Code that requires *fork* should explicitly specify that when creating + their :class:`ProcessPoolExecutor` by passing a + ``mp_context=multiprocessing.get_context('fork')`` parameter. .. _processpoolexecutor-example: |