diff options
| -rw-r--r-- | Doc/library/multiprocessing.rst | 24 | ||||
| -rw-r--r-- | Lib/multiprocessing/queues.py | 3 | ||||
| -rw-r--r-- | Misc/NEWS | 3 |
3 files changed, 21 insertions, 9 deletions
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst index cbec330..4d5f308 100644 --- a/Doc/library/multiprocessing.rst +++ b/Doc/library/multiprocessing.rst @@ -262,14 +262,6 @@ that only one process prints to standard output at a time:: 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 @@ For an example of the usage of queues for interprocess communication see 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 @@ object -- see :ref:`multiprocessing-managers`. 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 index f650771..c91535d 100644 --- a/Lib/multiprocessing/queues.py +++ b/Lib/multiprocessing/queues.py @@ -35,7 +35,8 @@ class Queue(object): 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() @@ -27,6 +27,9 @@ Library - Issue #23881: urllib.request.ftpwrapper constructor now closes the socket if the FTP connection failed to fix a ResourceWarning. +- Issue #23400: Raise same exception on both Python 2 and 3 if sem_open is not + available. Patch by Davin Potts. + - Issue #15133: _tkinter.tkapp.getboolean() now supports Tcl_Obj and always returns bool. tkinter.BooleanVar now validates input values (accepted bool, int, str, and Tcl_Obj). tkinter.BooleanVar.get() now always returns bool. |