#2493 closed defect (fixed)

Remove notepads

Reported by: Sebastian Huber Owned by: Joel Sherrill <joel.sherrill@…>
Priority: normal Milestone: 4.12.0
Component: unspecified Version: 4.12
Severity: normal Keywords:
Cc:

Description

Notepads were marked as obsolete in #2265. Next step is to remove them. Documentation should mention that notepads are removed an list the alternatives, e.g. POSIX keys or thread local storage.

Attachments (1)

0001-api-Remove-deprecated-Notepads.patch (154.0 KB) - added by Aun-Ali Zaidi on Dec 23, 2015 at 9:06:32 PM.

Download all attachments as: .zip

Change History (7)

comment:1 Changed on Dec 15, 2015 at 10:54:46 AM by Sebastian Huber

  • Remove RTEMS_API_Control::Notepads
  • Remove all rtems_task_*note*() functions and now unused dependencies.
  • Build with all tests enabled and fix all compile and link time errors.
  • Run tests without regressions.
  • Remove RTEMS_tasks_MP_Packet::note*.
  • Build with --enable-multiprocessing.
  • Build with all tests enabled and fix all compile and link time errors.
  • Run tests without regressions.
  • Update documentation, to be defined.
Last edited on Dec 22, 2015 at 2:20:07 PM by Sebastian Huber (previous) (diff)

comment:2 Changed on Dec 23, 2015 at 9:10:03 PM by Aun-Ali Zaidi

Notepads where a feature of RTEMS' tasks that simply functioned in the same way as POSIX keys
or threaded local storage (TLS). They were introduced well before per task variables, which
are also deprecated, and were barely used in favor of their POSIX alternatives.

In addition to their scarce usage, Notepads took up unnecessary memory.
For each task:

  • 16 32-bit integers were allocated.
  • A total of 64 bytes per task per thread.

This is especially critical in low memory and safety-critical applications.

They are also defined as uint32_t, and therefore are not guaranteed to hold a pointer.

Lastly, they are not portable solutions for SMP and uniprocessor systems, like POSIX
keys and TLS.

I am closing this ticket once the patch is committed.

comment:3 Changed on Dec 24, 2015 at 11:05:02 PM by Joel Sherrill <joel.sherrill@…>

Owner: set to Joel Sherrill <joel.sherrill@…>
Resolution: fixed
Status: newclosed

In c924e8502f6ad340acfae0e55443d0acde45fdf1/rtems:

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

closes #2493.

comment:4 Changed on May 11, 2017 at 7:31:02 AM by Sebastian Huber

Milestone: 4.124.12.0

comment:5 Changed on May 29, 2017 at 6:02:19 AM by Sebastian Huber <sebastian.huber@…>

In afa5b89/rtems:

ada: Remove task notepad support

Update #2493.

comment:6 Changed on Oct 9, 2017 at 6:05:48 AM by Sebastian Huber <sebastian.huber@…>

In d8f7bdc/rtems-docs:

c-user: Add obsolete configuration options section

Update #2493.
Update #3112.
Update #3113.
Update #3114.
Update #3115.
Update #3116.

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