Fix issue 4660: spurious task_done errors in multiprocessing, remove doc note for from_address

4 files changed, 20 insertions, 8 deletions

diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index 9e53aa5635..66c73a146b 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -1153,11 +1153,6 @@ their parent process exits.  The manager classes are defined in the
 
       Run the server in the current process.
 
-   .. method:: from_address(address, authkey)
-
-      A class method which creates a manager object referring to a pre-existing
-      server process which is using the given address and authentication key.
-
    .. method:: get_server()
 
       Returns a :class:`Server` object which represents the actual server under
diff --git a/Lib/multiprocessing/queues.py b/Lib/multiprocessing/queues.py
index 5df58825b5..ea279911b6 100644
--- a/Lib/multiprocessing/queues.py
+++ b/Lib/multiprocessing/queues.py
@@ -282,9 +282,22 @@ class JoinableQueue(Queue):
         Queue.__setstate__(self, state[:-2])
         self._cond, self._unfinished_tasks = state[-2:]
 
-    def put(self, item, block=True, timeout=None):
-        Queue.put(self, item, block, timeout)
-        self._unfinished_tasks.release()
+    def put(self, obj, block=True, timeout=None):
+        assert not self._closed
+        if not self._sem.acquire(block, timeout):
+            raise Full
+
+        self._notempty.acquire()
+        self._cond.acquire()
+        try:
+            if self._thread is None:
+                self._start_thread()
+            self._buffer.append(obj)
+            self._unfinished_tasks.release()
+            self._notempty.notify()
+        finally:
+            self._cond.release()
+            self._notempty.release()
 
     def task_done(self):
         self._cond.acquire()
diff --git a/Misc/ACKS b/Misc/ACKS
index 0ecbb5186c..defa80273e 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -485,6 +485,7 @@ Craig McPheeters
 Lambert Meertens
 Bill van Melle
 Lucas Prado Melo
+Brian Merrell
 Luke Mewburn
 Mike Meyer
 Steven Miale
diff --git a/Misc/NEWS b/Misc/NEWS
index 24232620ea..9fd2a513c0 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -354,6 +354,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #4660: If a multiprocessing.JoinableQueue.put() was preempted, it was
+  possible to get a spurious 'task_done() called too many times' error.
+
 - Issue #6595: The Decimal constructor now allows arbitrary Unicode
   decimal digits in input, as recommended by the standard.  Previously
   it was restricted to accepting [0-9].