[rtems commit] user/task.t: Add advice on transitioning use of notepads

[Joel Sherril]

Module:    rtems
Branch:    master
Commit:    c924e8502f6ad340acfae0e55443d0acde45fdf1
Changeset: http://git.rtems.org/rtems/commit/?id=c924e8502f6ad340acfae0e55443d0acde45fdf1

Author:    Joel Sherrill <joel.sherrill at oarcorp.com>
Date:      Thu Dec 24 17:03:51 2015 -0600

user/task.t: Add advice on transitioning use of notepads

closes #2493.

---

 doc/user/task.t | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/doc/user/task.t b/doc/user/task.t
index 6d0ff54..c51fbf3 100644
--- a/doc/user/task.t
+++ b/doc/user/task.t
@@ -661,6 +661,27 @@ task to delete itself by sending a "delete self" message, event,
 or signal, or by restarting the task with special arguments
 which instruct the task to delete itself.
 
+ at subsection Transition Advice for Obsolete Directives
+
+ at subsubsection Notepads
+ at ifset is-C
+ at findex rtems_task_get_note
+ at findex rtems_task_set_note
+ at end ifset
+
+Task notepads and the associated directives
+ at code{@value{DIRPREFIX}task_get_note} and
+ at code{@value{DIRPREFIX}task_set_note} were removed after the 4.11 Release
+Series. These were never thread-safe to access and subject to conflicting
+use of the notepad index by libraries which were designed independently.
+
+It is recommended that applications be modified to use services
+which are thread safe and not subject to issues with multiple applications
+conflicting over the key (e.g. notepad index) selection. For most 
+applications, POSIX Keys should be used. These are available in all RTEMS
+build configurations. It is also possible that Thread Local Storage is
+an option for some use cases. 
+
 @section Directives
 
 This section details the task manager's directives.  A