diff -r c0224ff67cdd Lib/concurrent/futures/_base.py
--- a/Lib/concurrent/futures/_base.py	Mon Oct 13 10:39:41 2014 +0100
+++ b/Lib/concurrent/futures/_base.py	Mon Oct 13 19:13:58 2014 +0100
@@ -18,7 +18,7 @@
 RUNNING = 'RUNNING'
 # The future was cancelled by the user...
 CANCELLED = 'CANCELLED'
-# ...and _Waiter.add_cancelled() was called by a worker.
+# ...and `set_running_or_notify_cancel` was called by a worker.
 CANCELLED_AND_NOTIFIED = 'CANCELLED_AND_NOTIFIED'
 FINISHED = 'FINISHED'
 
@@ -446,8 +446,7 @@
         Should only be used by Executor implementations and unit tests.
 
         If the future has been cancelled (cancel() was called and returned
-        True) then any threads waiting on the future completing (though calls
-        to as_completed() or wait()) are notified and False is returned.
+        True) False is returned.
 
         If the future was not cancelled then it is put in the running state
         (future calls to running() will return True) and True is returned.
@@ -468,8 +467,6 @@
                 self._state = CANCELLED_AND_NOTIFIED
                 for waiter in self._waiters:
                     waiter.add_cancelled(self)
-                # self._condition.notify_all() is not necessary because
-                # self.cancel() triggers a notification.
                 return False
             elif self._state == PENDING:
                 self._state = RUNNING