Apr 9, 2025 · Apr 16, 2025 · May 2, 2025 · May 19, 2025 · May 3, 2025
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
   A solitary difference from its close analog exists: its ``acquire`` method's
   first argument is named *block*, as is consistent with :meth:`Lock.acquire`.

   .. method:: get_value()

      Return the current value of semaphore.

      Note that this may raise :exc:`NotImplementedError` on platforms like
      macOS where ``sem_getvalue()`` is not implemented.

 .. note::

   On macOS, ``sem_timedwait`` is unsupported, so calling ``acquire()`` with
diff --git a/Lib/multiprocessing/queues.py b/Lib/multiprocessing/queues.py

    def qsize(self):
        # Raises NotImplementedError on Mac OSX because of broken sem_getvalue()
        return self._maxsize - self._sem._semlock._get_value()
        return self._maxsize - self._sem.get_value()

    def empty(self):
        return not self._poll()
diff --git a/Lib/multiprocessing/synchronize.py b/Lib/multiprocessing/synchronize.py
        SemLock.__init__(self, SEMAPHORE, value, SEM_VALUE_MAX, ctx=ctx)

    def get_value(self):
        '''Returns current value of Semaphore.

        Raises NotImplementedError on Mac OSX
        because of broken sem_getvalue().
        '''
        return self._semlock._get_value()

    def __repr__(self):
        try:
            value = self._semlock._get_value()
            value = self.get_value()
        except Exception:
            value = 'unknown'
        return '<%s(value=%s)>' % (self.__class__.__name__, value)

    def __repr__(self):
        try:
            value = self._semlock._get_value()
            value = self.get_value()
        except Exception:
            value = 'unknown'
        return '<%s(value=%s, maxvalue=%s)>' % \

    def __repr__(self):
        try:
            num_waiters = (self._sleeping_count._semlock._get_value() -
                           self._woken_count._semlock._get_value())
            num_waiters = (self._sleeping_count.get_value() -
                           self._woken_count.get_value())
        except Exception:
            num_waiters = 'unknown'
        return '<%s(%s, %s)>' % (self.__class__.__name__, self._lock, num_waiters)
diff --git a/Misc/NEWS.d/next/Library/2025-05-19-15-49-25.gh-issue-133146.NJYTUb.rst b/Misc/NEWS.d/next/Library/2025-05-19-15-49-25.gh-issue-133146.NJYTUb.rst
 Document the old public :meth:`get_value<multiprocessing.synchronized.Semaphore>`. Replace code using private attributes with this public method in ``multiprocessing.synchronized.py`` and ``multiprocessing.queues.py`` files
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1521,6 +1521,13 @@ object -- see :ref:`multiprocessing-managers`.
		A solitary difference from its close analog exists: its ``acquire`` method's
		first argument is named block, as is consistent with :meth:`Lock.acquire`.

		.. method:: get_value()

		Return the current value of semaphore.

		Note that this may raise :exc:`NotImplementedError` on platforms like
		macOS where ``sem_getvalue()`` is not implemented.

		.. note::

		On macOS, ``sem_timedwait`` is unsupported, so calling ``acquire()`` with
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -121,7 +121,7 @@ def get(self, block=True, timeout=None):

		def qsize(self):
		# Raises NotImplementedError on Mac OSX because of broken sem_getvalue()
		return self._maxsize - self._sem._semlock._get_value()
		return self._maxsize - self._sem.get_value()

		def empty(self):
		return not self._poll()
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -135,11 +135,16 @@ def __init__(self, value=1, *, ctx):
		SemLock.__init__(self, SEMAPHORE, value, SEM_VALUE_MAX, ctx=ctx)

		def get_value(self):
		'''Returns current value of Semaphore.

		Raises NotImplementedError on Mac OSX
		because of broken sem_getvalue().
		'''
Comment on lines +138 to +142 Copy link ContributorAuthor YvesDupMay 3, 2025 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. This file has no docstring. Should we remove this one ?
		return self._semlock._get_value()

		def __repr__(self):
		try:
		value = self._semlock._get_value()
		value = self.get_value()
		except Exception:
		value = 'unknown'
		return '<%s(value=%s)>' % (self.__class__.__name__, value)
Expand All		@@ -155,7 +160,7 @@ def __init__(self, value=1, *, ctx):

		def __repr__(self):
		try:
		value = self._semlock._get_value()
		value = self.get_value()
		except Exception:
		value = 'unknown'
		return '<%s(value=%s, maxvalue=%s)>' % \
Expand DownExpand Up		@@ -247,8 +252,8 @@ def _make_methods(self):

		def __repr__(self):
		try:
		num_waiters = (self._sleeping_count._semlock._get_value() -
		self._woken_count._semlock._get_value())
		num_waiters = (self._sleeping_count.get_value() -
		self._woken_count.get_value())
		except Exception:
		num_waiters = 'unknown'
		return '<%s(%s, %s)>' % (self.__class__.__name__, self._lock, num_waiters)
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Document the old public :meth:`get_value<multiprocessing.synchronized.Semaphore>`. Replace code using private attributes with this public method in ``multiprocessing.synchronized.py`` and ``multiprocessing.queues.py`` files