rtems-docs/c-user/task/removed-directives.rst

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.. SPDX-License-Identifier: CC-BY-SA-4.0
.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
Removed Directives
==================
.. raw:: latex
\clearpage
.. index:: get task notepad entry
.. index:: rtems_task_get_note()
.. _rtems_task_get_note:
TASK_GET_NOTE - Get task notepad entry
--------------------------------------
.. warning::
This directive was removed in RTEMS 5.1.
CALLING SEQUENCE:
.. code-block:: c
rtems_status_code rtems_task_get_note(
rtems_id id,
uint32_t notepad,
uint32_t *note
);
DIRECTIVE STATUS CODES:
.. list-table::
:class: rtems-table
* - ``RTEMS_SUCCESSFUL``
- note value obtained successfully
* - ``RTEMS_INVALID_ADDRESS``
- ``note`` parameter is NULL
* - ``RTEMS_INVALID_ID``
- invalid task id
* - ``RTEMS_INVALID_NUMBER``
- invalid notepad location
DESCRIPTION:
This directive returns the note contained in the notepad location of the
task specified by id.
NOTES:
This directive will not cause the running task to be preempted.
If id is set to ``RTEMS_SELF``, the calling task accesses its own notepad.
The sixteen notepad locations can be accessed using the constants
``RTEMS_NOTEPAD_0`` through ``RTEMS_NOTEPAD_15``.
Getting a note of a global task which does not reside on the local node
will generate a request to the remote node to obtain the notepad entry of
the specified task.
.. raw:: latex
\clearpage
.. index:: set task notepad entry
.. index:: rtems_task_set_note()
.. _rtems_task_set_note:
TASK_SET_NOTE - Set task notepad entry
--------------------------------------
.. warning::
This directive was removed in RTEMS 5.1.
CALLING SEQUENCE:
.. code-block:: c
rtems_status_code rtems_task_set_note(
rtems_id id,
uint32_t notepad,
uint32_t note
);
DIRECTIVE STATUS CODES:
.. list-table::
:class: rtems-table
* - ``RTEMS_SUCCESSFUL``
- note set successfully
* - ``RTEMS_INVALID_ID``
- invalid task id
* - ``RTEMS_INVALID_NUMBER``
- invalid notepad location
DESCRIPTION:
This directive sets the notepad entry for the task specified by id to the
value note.
NOTES:
If ``id`` is set to ``RTEMS_SELF``, the calling task accesses its own
notepad.
This directive will not cause the running task to be preempted.
The sixteen notepad locations can be accessed using the constants
``RTEMS_NOTEPAD_0`` through ``RTEMS_NOTEPAD_15``.
Setting a note of a global task which does not reside on the local node
will generate a request to the remote node to set the notepad entry of the
specified task.
.. raw:: latex
\clearpage
.. index:: per-task variable
.. index:: task private variable
.. index:: task private data
.. index:: rtems_task_variable_add()
.. _rtems_task_variable_add:
TASK_VARIABLE_ADD - Associate per task variable
-----------------------------------------------
.. warning::
This directive was removed in RTEMS 5.1.
CALLING SEQUENCE:
.. code-block:: c
rtems_status_code rtems_task_variable_add(
rtems_id tid,
void **task_variable,
void (*dtor)(void *)
);
DIRECTIVE STATUS CODES:
.. list-table::
:class: rtems-table
* - ``RTEMS_SUCCESSFUL``
- per task variable added successfully
* - ``RTEMS_INVALID_ADDRESS``
- ``task_variable`` is NULL
* - ``RTEMS_INVALID_ID``
- invalid task id
* - ``RTEMS_NO_MEMORY``
- invalid task id
* - ``RTEMS_ILLEGAL_ON_REMOTE_OBJECT``
- not supported on remote tasks
DESCRIPTION:
This directive adds the memory location specified by the ptr argument to
the context of the given task. The variable will then be private to the
task. The task can access and modify the variable, but the modifications
will not appear to other tasks, and other tasks' modifications to that
variable will not affect the value seen by the task. This is accomplished
by saving and restoring the variable's value each time a task switch occurs
to or from the calling task. If the dtor argument is non-NULL it specifies
the address of a 'destructor' function which will be called when the task
is deleted. The argument passed to the destructor function is the task's
value of the variable.
NOTES:
Task variables increase the context switch time to and from the tasks that
own them so it is desirable to minimize the number of task variables. One
efficient method is to have a single task variable that is a pointer to a
dynamically allocated structure containing the task's private 'global'
data. In this case the destructor function could be 'free'.
Per-task variables are disabled in SMP configurations and this service is
not available.
.. raw:: latex
\clearpage
.. index:: get per-task variable
.. index:: obtain per-task variable
.. index:: rtems_task_variable_get()
.. _rtems_task_variable_get:
TASK_VARIABLE_GET - Obtain value of a per task variable
-------------------------------------------------------
.. warning::
This directive was removed in RTEMS 5.1.
CALLING SEQUENCE:
.. code-block:: c
rtems_status_code rtems_task_variable_get(
rtems_id tid,
void **task_variable,
void **task_variable_value
);
DIRECTIVE STATUS CODES:
.. list-table::
:class: rtems-table
* - ``RTEMS_SUCCESSFUL``
- per task variable obtained successfully
* - ``RTEMS_INVALID_ADDRESS``
- ``task_variable`` is NULL
* - ``RTEMS_INVALID_ADDRESS``
- ``task_variable_value`` is NULL
* - ``RTEMS_INVALID_ADDRESS``
- ``task_variable`` is not found
* - ``RTEMS_NO_MEMORY``
- invalid task id
* - ``RTEMS_ILLEGAL_ON_REMOTE_OBJECT``
- not supported on remote tasks
DESCRIPTION:
This directive looks up the private value of a task variable for a
specified task and stores that value in the location pointed to by the
result argument. The specified task is usually not the calling task, which
can get its private value by directly accessing the variable.
NOTES:
If you change memory which ``task_variable_value`` points to, remember to
declare that memory as volatile, so that the compiler will optimize it
correctly. In this case both the pointer ``task_variable_value`` and data
referenced by ``task_variable_value`` should be considered volatile.
Per-task variables are disabled in SMP configurations and this service is
not available.
.. raw:: latex
\clearpage
.. index:: per-task variable
.. index:: task private variable
.. index:: task private data
.. index:: rtems_task_variable_delete()
.. _rtems_task_variable_delete:
TASK_VARIABLE_DELETE - Remove per task variable
-----------------------------------------------
.. warning::
This directive was removed in RTEMS 5.1.
CALLING SEQUENCE:
.. code-block:: c
rtems_status_code rtems_task_variable_delete(
rtems_id id,
void **task_variable
);
DIRECTIVE STATUS CODES:
.. list-table::
:class: rtems-table
* - ``RTEMS_SUCCESSFUL``
- per task variable deleted successfully
* - ``RTEMS_INVALID_ID``
- invalid task id
* - ``RTEMS_NO_MEMORY``
- invalid task id
* - ``RTEMS_INVALID_ADDRESS``
- ``task_variable`` is NULL
* - ``RTEMS_ILLEGAL_ON_REMOTE_OBJECT``
- not supported on remote tasks
DESCRIPTION:
This directive removes the given location from a task's context.
NOTES:
Per-task variables are disabled in SMP configurations and this service is
not available.