7.6. Removed Directives¶
7.6.1. TASK_GET_NOTE - Get task notepad entry¶
Warning
This directive was removed in RTEMS 5.1.
- CALLING SEQUENCE:
rtems_status_code rtems_task_get_note( rtems_id id, uint32_t notepad, uint32_t *note );
- DIRECTIVE STATUS CODES:
RTEMS_SUCCESSFUL
note value obtained successfully
RTEMS_INVALID_ADDRESS
note
parameter is NULLRTEMS_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
throughRTEMS_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.
7.6.2. TASK_SET_NOTE - Set task notepad entry¶
Warning
This directive was removed in RTEMS 5.1.
- CALLING SEQUENCE:
rtems_status_code rtems_task_set_note( rtems_id id, uint32_t notepad, uint32_t note );
- DIRECTIVE STATUS CODES:
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 toRTEMS_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
throughRTEMS_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.
7.6.3. TASK_VARIABLE_ADD - Associate per task variable¶
Warning
This directive was removed in RTEMS 5.1.
- CALLING SEQUENCE:
rtems_status_code rtems_task_variable_add( rtems_id tid, void **task_variable, void (*dtor)(void *) );
- DIRECTIVE STATUS CODES:
RTEMS_SUCCESSFUL
per task variable added successfully
RTEMS_INVALID_ADDRESS
task_variable
is NULLRTEMS_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.
7.6.4. TASK_VARIABLE_GET - Obtain value of a per task variable¶
Warning
This directive was removed in RTEMS 5.1.
- CALLING SEQUENCE:
rtems_status_code rtems_task_variable_get( rtems_id tid, void **task_variable, void **task_variable_value );
- DIRECTIVE STATUS CODES:
RTEMS_SUCCESSFUL
per task variable obtained successfully
RTEMS_INVALID_ADDRESS
task_variable
is NULLRTEMS_INVALID_ADDRESS
task_variable_value
is NULLRTEMS_INVALID_ADDRESS
task_variable
is not foundRTEMS_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 pointertask_variable_value
and data referenced bytask_variable_value
should be considered volatile.Per-task variables are disabled in SMP configurations and this service is not available.
7.6.5. TASK_VARIABLE_DELETE - Remove per task variable¶
Warning
This directive was removed in RTEMS 5.1.
- CALLING SEQUENCE:
rtems_status_code rtems_task_variable_delete( rtems_id id, void **task_variable );
- DIRECTIVE STATUS CODES:
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 NULLRTEMS_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.