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Diffstat (limited to 'c-user/scheduling_concepts.rst')
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diff --git a/c-user/scheduling_concepts.rst b/c-user/scheduling_concepts.rst index 8d25424..cea863d 100644 --- a/c-user/scheduling_concepts.rst +++ b/c-user/scheduling_concepts.rst @@ -25,6 +25,16 @@ appropriately called the scheduler. The scheduler's sole purpose is to allocate the all important resource of processor time to the various tasks competing for attention. +The directives provided by the scheduler manager are: + +- rtems_scheduler_ident_ - Get ID of a scheduler + +- rtems_scheduler_get_processor_set_ - Get processor set of a scheduler + +- rtems_scheduler_add_processor_ - Add processor to a scheduler + +- rtems_scheduler_remove_processor_ - Remove processor from a scheduler + Scheduling Algorithms ===================== @@ -435,3 +445,168 @@ conditions: - The running task raises the priority of a task above its own and the running task is in preemption mode. + +Directives +========== + +This section details the scheduler manager. A subsection is dedicated to each +of these services and describes the calling sequence, related constants, usage, +and status codes. + +.. raw:: latex + + \clearpage + +.. _rtems_scheduler_ident: + +SCHEDULER_IDENT - Get ID of a scheduler +--------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_scheduler_ident( + rtems_name name, + rtems_id *id + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - Successful operation. + * - ``RTEMS_INVALID_ADDRESS`` + - The ``id`` parameter is ``NULL``. + * - ``RTEMS_INVALID_NAME`` + - Invalid scheduler name. + +DESCRIPTION: + Identifies a scheduler by its name. The scheduler name is determined by + the scheduler configuration. See :ref:`Configuring Clustered Schedulers` + and :ref:`Configuring a Scheduler Name`. + +NOTES: + None. + +.. raw:: latex + + \clearpage + +.. _rtems_scheduler_get_processor_set: + +SCHEDULER_GET_PROCESSOR_SET - Get processor set of a scheduler +-------------------------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_scheduler_get_processor_set( + rtems_id scheduler_id, + size_t cpusetsize, + cpu_set_t *cpuset + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - Successful operation. + * - ``RTEMS_INVALID_ID`` + - Invalid scheduler instance identifier. + * - ``RTEMS_INVALID_ADDRESS`` + - The ``cpuset`` parameter is ``NULL``. + * - ``RTEMS_INVALID_NUMBER`` + - The processor set buffer is too small for the set of processors owned + by the scheduler instance. + +DESCRIPTION: + Returns the processor set owned by the scheduler instance in ``cpuset``. A + set bit in the processor set means that this processor is owned by the + scheduler instance and a cleared bit means the opposite. + +NOTES: + None. + +.. raw:: latex + + \clearpage + +.. _rtems_scheduler_add_processor: + +SCHEDULER_ADD_PROCESSOR - Add processor to a scheduler +------------------------------------------------------ + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_scheduler_add_processor( + rtems_id scheduler_id, + uint32_t cpu_index + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - Successful operation. + * - ``RTEMS_INVALID_ID`` + - Invalid scheduler instance identifier. + * - ``RTEMS_NOT_CONFIGURED`` + - The processor is not configured to be used by the application. + * - ``RTEMS_INCORRECT_STATE`` + - The processor is configured to be used by the application, however, it + is not online. + * - ``RTEMS_RESOURCE_IN_USE`` + - The processor is already assigned to a scheduler instance. + +DESCRIPTION: + Adds a processor to the set of processors owned by the specified scheduler + instance. + +NOTES: + Must be called from task context. This operation obtains and releases the + objects allocator lock. + +.. raw:: latex + + \clearpage + +.. _rtems_scheduler_remove_processor: + +SCHEDULER_REMOVE_PROCESSOR - Remove processor from a scheduler +-------------------------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_scheduler_remove_processor( + rtems_id scheduler_id, + uint32_t cpu_index + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - Successful operation. + * - ``RTEMS_INVALID_ID`` + - Invalid scheduler instance identifier. + * - ``RTEMS_INVALID_NUMBER`` + - The processor is not owned by the specified scheduler instance. + * - ``RTEMS_RESOURCE_IN_USE`` + - The set of processors owned by the specified scheduler instance would + be empty after the processor removal and there exists a non-idle task + that uses this scheduler instance as its home scheduler instance. + +DESCRIPTION: + Removes a processor from set of processors owned by the specified scheduler + instance. + +NOTES: + Must be called from task context. This operation obtains and releases the + objects allocator lock. Removing a processor from a scheduler is a complex + operation that involves all tasks of the system. |