Issue #17273: Clarify that pool methods can only be used by parent process.

diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index 3f368a316a407672d822ed4233d3699bd719d2c0..0756470c94a2fd8b0a2586e4a43756d5f754ba2f 100644 (file)
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -287,6 +287,9 @@ For example::
        print result.get(timeout=1)           # prints "100" unless your computer is *very* slow
        print pool.map(f, range(10))          # prints "[0, 1, 4,..., 81]"
 
+Note that the methods of a pool should only ever be used by the
+process which created it.
+
 
 Reference
 ---------
@@ -1599,6 +1602,9 @@ with the :class:`Pool` class.
    *initializer* is not ``None`` then each worker process will call
    ``initializer(*initargs)`` when it starts.
 
+   Note that the methods of the pool object should only be called by
+   the process which created the pool.
+
    .. versionadded:: 2.7
       *maxtasksperchild* is the number of tasks a worker process can complete
       before it will exit and be replaced with a fresh worker process, to enable