diff options
Diffstat (limited to 'c-user/timer/directives.rst')
| -rw-r--r-- | c-user/timer/directives.rst | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/c-user/timer/directives.rst b/c-user/timer/directives.rst new file mode 100644 index 0000000..d9b9877 --- /dev/null +++ b/c-user/timer/directives.rst @@ -0,0 +1,463 @@ +.. SPDX-License-Identifier: CC-BY-SA-4.0 + +.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR) + +Directives +========== + +This section details the timer manager's directives. A subsection is dedicated +to each of this manager's directives and describes the calling sequence, +related constants, usage, and status codes. + +.. raw:: latex + + \clearpage +.. index:: create a timer +.. index:: rtems_timer_create + +.. _rtems_timer_create: + +TIMER_CREATE - Create a timer +----------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_create( + rtems_name name, + rtems_id *id + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer created successfully + * - ``RTEMS_INVALID_ADDRESS`` + - ``id`` is NULL + * - ``RTEMS_INVALID_NAME`` + - invalid timer name + * - ``RTEMS_TOO_MANY`` + - too many timers created + +DESCRIPTION: + This directive creates a timer. The assigned timer id is returned in id. + This id is used to access the timer with other timer manager directives. + For control and maintenance of the timer, RTEMS allocates a TMCB from the + local TMCB free pool and initializes it. + +NOTES: + This directive will obtain the allocator mutex and may cause the calling + task to be preempted. + + In SMP configurations, the processor of the currently executing thread + determines the processor used for the created timer. During the life-time + of the timer this processor is used to manage the timer internally. + +.. raw:: latex + + \clearpage + +.. index:: obtain the ID of a timer +.. index:: rtems_timer_ident + +.. _rtems_timer_ident: + +TIMER_IDENT - Get ID of a timer +------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_ident( + rtems_name name, + rtems_id *id + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer identified successfully + * - ``RTEMS_INVALID_ADDRESS`` + - ``id`` is NULL + * - ``RTEMS_INVALID_NAME`` + - timer name not found + +DESCRIPTION: + This directive obtains the timer id associated with the timer name to be + acquired. If the timer name is not unique, then the timer id will match + one of the timers with that name. However, this timer id is not guaranteed + to correspond to the desired timer. The timer id is used to access this + timer in other timer related directives. + +NOTES: + This directive will not cause the running task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: cancel a timer +.. index:: rtems_timer_cancel + +.. _rtems_timer_cancel: + +TIMER_CANCEL - Cancel a timer +----------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_cancel( + rtems_id id + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer canceled successfully + * - ``RTEMS_INVALID_ID`` + - invalid timer id + +DESCRIPTION: + This directive cancels the timer id. This timer will be reinitiated by the + next invocation of ``rtems_timer_reset``, ``rtems_timer_fire_after``, or + ``rtems_timer_fire_when`` with this id. + +NOTES: + This directive will not cause the running task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: delete a timer +.. index:: rtems_timer_delete + +.. _rtems_timer_delete: + +TIMER_DELETE - Delete a timer +----------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_delete( + rtems_id id + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer deleted successfully + * - ``RTEMS_INVALID_ID`` + - invalid timer id + +DESCRIPTION: + This directive deletes the timer specified by id. If the timer is running, + it is automatically canceled. The TMCB for the deleted timer is reclaimed + by RTEMS. + +NOTES: + This directive will obtain the allocator mutex and may cause the calling + task to be preempted. + + A timer can be deleted by a task other than the task which created the + timer. + +.. raw:: latex + + \clearpage + +.. index:: fire a timer after an interval +.. index:: rtems_timer_fire_after + +.. _rtems_timer_fire_after: + +TIMER_FIRE_AFTER - Fire timer after interval +-------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_fire_after( + rtems_id id, + rtems_interval ticks, + rtems_timer_service_routine_entry routine, + void *user_data + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer initiated successfully + * - ``RTEMS_INVALID_ADDRESS`` + - ``routine`` is NULL + * - ``RTEMS_INVALID_ID`` + - invalid timer id + * - ``RTEMS_INVALID_NUMBER`` + - invalid interval + +DESCRIPTION: + This directive initiates the timer specified by id. If the timer is + running, it is automatically canceled before being initiated. The timer is + scheduled to fire after an interval ticks clock ticks has passed. When the + timer fires, the timer service routine routine will be invoked with the + argument user_data. + +NOTES: + This directive will not cause the running task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: fire a timer at wall time +.. index:: rtems_timer_fire_when + +.. _rtems_timer_fire_when: + +TIMER_FIRE_WHEN - Fire timer when specified +------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_fire_when( + rtems_id id, + rtems_time_of_day *wall_time, + rtems_timer_service_routine_entry routine, + void *user_data + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer initiated successfully + * - ``RTEMS_INVALID_ADDRESS`` + - ``routine`` is NULL + * - ``RTEMS_INVALID_ADDRESS`` + - ``wall_time`` is NULL + * - ``RTEMS_INVALID_ID`` + - invalid timer id + * - ``RTEMS_NOT_DEFINED`` + - system date and time is not set + * - ``RTEMS_INVALID_CLOCK`` + - invalid time of day + +DESCRIPTION: + This directive initiates the timer specified by id. If the timer is + running, it is automatically canceled before being initiated. The timer is + scheduled to fire at the time of day specified by wall_time. When the + timer fires, the timer service routine routine will be invoked with the + argument user_data. + +NOTES: + This directive will not cause the running task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: initiate the Timer Server +.. index:: rtems_timer_initiate_server + +.. _rtems_timer_initiate_server: + +TIMER_INITIATE_SERVER - Initiate server for task-based timers +------------------------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_initiate_server( + uint32_t priority, + uint32_t stack_size, + rtems_attribute attribute_set + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - Timer Server initiated successfully + * - ``RTEMS_TOO_MANY`` + - too many tasks created + +DESCRIPTION: + This directive initiates the Timer Server task. This task is responsible + for executing all timers initiated via the + ``rtems_timer_server_fire_after`` or ``rtems_timer_server_fire_when`` + directives. + +NOTES: + This directive could cause the calling task to be preempted. + + The Timer Server task is created using the ``rtems_task_create`` service + and must be accounted for when configuring the system. + + Even through this directive invokes the ``rtems_task_create`` and + ``rtems_task_start`` directives, it should only fail due to resource + allocation problems. + +.. raw:: latex + + \clearpage + +.. index:: fire task-based a timer after an interval +.. index:: rtems_timer_server_fire_after + +.. _rtems_timer_server_fire_after: + +TIMER_SERVER_FIRE_AFTER - Fire task-based timer after interval +-------------------------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_server_fire_after( + rtems_id id, + rtems_interval ticks, + rtems_timer_service_routine_entry routine, + void *user_data + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer initiated successfully + * - ``RTEMS_INVALID_ADDRESS`` + - ``routine`` is NULL + * - ``RTEMS_INVALID_ID`` + - invalid timer id + * - ``RTEMS_INVALID_NUMBER`` + - invalid interval + * - ``RTEMS_INCORRECT_STATE`` + - Timer Server not initiated + +DESCRIPTION: + This directive initiates the timer specified by id and specifies that when + it fires it will be executed by the Timer Server. + + If the timer is running, it is automatically canceled before being + initiated. The timer is scheduled to fire after an interval ticks clock + ticks has passed. When the timer fires, the timer service routine routine + will be invoked with the argument user_data. + +NOTES: + This directive will not cause the running task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: fire a task-based timer at wall time +.. index:: rtems_timer_server_fire_when + +.. _rtems_timer_server_fire_when: + +TIMER_SERVER_FIRE_WHEN - Fire task-based timer when specified +------------------------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_server_fire_when( + rtems_id id, + rtems_time_of_day *wall_time, + rtems_timer_service_routine_entry routine, + void *user_data + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer initiated successfully + * - ``RTEMS_INVALID_ADDRESS`` + - ``routine`` is NULL + * - ``RTEMS_INVALID_ADDRESS`` + - ``wall_time`` is NULL + * - ``RTEMS_INVALID_ID`` + - invalid timer id + * - ``RTEMS_NOT_DEFINED`` + - system date and time is not set + * - ``RTEMS_INVALID_CLOCK`` + - invalid time of day + * - ``RTEMS_INCORRECT_STATE`` + - Timer Server not initiated + +DESCRIPTION: + This directive initiates the timer specified by id and specifies that when + it fires it will be executed by the Timer Server. + + If the timer is running, it is automatically canceled before being + initiated. The timer is scheduled to fire at the time of day specified by + wall_time. When the timer fires, the timer service routine routine will be + invoked with the argument user_data. + +NOTES: + This directive will not cause the running task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: reset a timer +.. index:: rtems_timer_reset + +.. _rtems_timer_reset: + +TIMER_RESET - Reset an interval timer +------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_timer_reset( + rtems_id id + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - timer reset successfully + * - ``RTEMS_INVALID_ID`` + - invalid timer id + * - ``RTEMS_NOT_DEFINED`` + - attempted to reset a when or newly created timer + +DESCRIPTION: + This directive resets the timer associated with id. This timer must have + been previously initiated with either the ``rtems_timer_fire_after`` or + ``rtems_timer_server_fire_after`` directive. If active the timer is + canceled, after which the timer is reinitiated using the same interval and + timer service routine which the original ``rtems_timer_fire_after`` or + ``rtems_timer_server_fire_after`` directive used. + +NOTES: + If the timer has not been used or the last usage of this timer was by a + ``rtems_timer_fire_when`` or ``rtems_timer_server_fire_when`` directive, + then the ``RTEMS_NOT_DEFINED`` error is returned. + + Restarting a cancelled after timer results in the timer being reinitiated + with its previous timer service routine and interval. + + This directive will not cause the running task to be preempted. |