Added respect_handler_level to QueueListener.

2 files changed, 18 insertions, 2 deletions

diff --git a/Doc/howto/logging-cookbook.rst b/Doc/howto/logging-cookbook.rst
index 57e23f9..e31b6c2 100644
--- a/Doc/howto/logging-cookbook.rst
+++ b/Doc/howto/logging-cookbook.rst
@@ -325,6 +325,15 @@ which, when run, will produce::
 
     MainThread: Look out!
 
+.. versionchanged:: 3.5
+   Prior to Python 3.5, the :class:`QueueListener` always passed every message
+   received from the queue to every handler it was initialized with. (This was
+   because it was assumed that level filtering was all done on the other side,
+   where the queue is filled.) From 3.5 onwards, this behaviour can be changed
+   by passing a keyword argument ``respect_handler_level=True`` to the
+   listener's constructor. When this is done, the listener compares the level
+   of each message with the handler's level, and only passes a message to a
+   handler if it's appropriate to do so.
 
 .. _network-logging:
 
diff --git a/Doc/library/logging.handlers.rst b/Doc/library/logging.handlers.rst
index 48c57cf..67403a9 100644
--- a/Doc/library/logging.handlers.rst
+++ b/Doc/library/logging.handlers.rst
@@ -953,13 +953,20 @@ applications where threads servicing clients need to respond as quickly as
 possible, while any potentially slow operations (such as sending an email via
 :class:`SMTPHandler`) are done on a separate thread.
 
-.. class:: QueueListener(queue, *handlers)
+.. class:: QueueListener(queue, *handlers, respect_handler_level=False)
 
    Returns a new instance of the :class:`QueueListener` class. The instance is
    initialized with the queue to send messages to and a list of handlers which
    will handle entries placed on the queue. The queue can be any queue-
    like object; it's passed as-is to the :meth:`dequeue` method, which needs
-   to know how to get messages from it.
+   to know how to get messages from it. If ``respect_handler_level`` is ``True``,
+   a handler's level is respected (compared with the level for the message) when
+   deciding whether to pass messages to that handler; otherwise, the behaviour
+   is as in previous Python versions - to always pass each message to each
+   handler.
+
+   .. versionchanged:: 3.5
+      The ``respect_handler_levels`` argument was added.
 
    .. method:: dequeue(block)