https://hg.python.org/cpython/rev/a49737bd6086
changeset: 95487:a49737bd6086
parent: 95485:e64197dad303
parent: 95486:749fd043de95
user: Berker Peksag <berker.peksag at gmail.com>
date: Wed Apr 08 17:57:44 2015 +0300
summary:
Issue #23400: Raise same exception on both Python 2 and 3 if sem_open is not available.
Patch by Davin Potts.
files:
Doc/library/multiprocessing.rst | 24 ++++++++++++++-------
Lib/multiprocessing/queues.py | 3 +-
Misc/NEWS | 3 ++
3 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -262,14 +262,6 @@
Without using the lock output from the different processes is liable to get all
mixed up.
-.. note::
-
- Some of this package's functionality requires a functioning shared semaphore
- implementation on the host operating system. Without one, the
- :mod:`multiprocessing.synchronize` module will be disabled, and attempts to
- import it will result in an :exc:`ImportError`. See
- :issue:`3770` for additional information.
-
Sharing state between processes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -808,6 +800,14 @@
immediately without waiting to flush enqueued data to the
underlying pipe, and you don't care about lost data.
+ .. note::
+
+ This class's functionality requires a functioning shared semaphore
+ implementation on the host operating system. Without one, the
+ functionality in this class will be disabled, and attempts to
+ instantiate a :class:`Queue` will result in an :exc:`ImportError`. See
+ :issue:`3770` for additional information. The same holds true for any
+ of the specialized queue types listed below.
.. class:: SimpleQueue()
@@ -1183,6 +1183,14 @@
This differs from the behaviour of :mod:`threading` where SIGINT will be
ignored while the equivalent blocking calls are in progress.
+.. note::
+
+ Some of this package's functionality requires a functioning shared semaphore
+ implementation on the host operating system. Without one, the
+ :mod:`multiprocessing.synchronize` module will be disabled, and attempts to
+ import it will result in an :exc:`ImportError`. See
+ :issue:`3770` for additional information.
+
Shared :mod:`ctypes` Objects
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/Lib/multiprocessing/queues.py b/Lib/multiprocessing/queues.py
--- a/Lib/multiprocessing/queues.py
+++ b/Lib/multiprocessing/queues.py
@@ -35,7 +35,8 @@
def __init__(self, maxsize=0, *, ctx):
if maxsize <= 0:
- maxsize = _multiprocessing.SemLock.SEM_VALUE_MAX
+ # Can raise ImportError (see issues #3770 and #23400)
+ from .synchronize import SEM_VALUE_MAX as maxsize
self._maxsize = maxsize
self._reader, self._writer = connection.Pipe(duplex=False)
self._rlock = ctx.Lock()
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -19,6 +19,9 @@
Library
-------
+- Issue #23400: Raise same exception on both Python 2 and 3 if sem_open is not
+ available. Patch by Davin Potts.
+
- Issue #10838: The subprocess now module includes SubprocessError and
TimeoutError in its list of exported names for the users wild enough
to use "from subprocess import *".
--
Repository URL: https://hg.python.org/cpython