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authorChris Johns <chrisj@rtems.org>2016-01-24 21:37:53 +1100
committerAmar Takhar <verm@darkbeer.org>2016-05-02 20:51:25 -0400
commitb8d3f6b3b7fd03102f8a06aaaec330a0293c95d2 (patch)
treea22972185fb78174ef4df3e530a79a9d41384669 /c_user/timer_manager.rst
parent0f5ccd4d6d63e622f4e43ca516e6f5df3f0a3150 (diff)
downloadrtems-docs-b8d3f6b3b7fd03102f8a06aaaec330a0293c95d2.tar.bz2
C user guide clean up. Up to timer manager.
Diffstat (limited to 'c_user/timer_manager.rst')
-rw-r--r--c_user/timer_manager.rst575
1 files changed, 312 insertions, 263 deletions
diff --git a/c_user/timer_manager.rst b/c_user/timer_manager.rst
index 2d83bf9..2e43770 100644
--- a/c_user/timer_manager.rst
+++ b/c_user/timer_manager.rst
@@ -1,3 +1,7 @@
+.. COMMENT: COPYRIGHT (c) 1988-2008.
+.. COMMENT: On-Line Applications Research Corporation (OAR).
+.. COMMENT: All rights reserved.
+
Timer Manager
#############
@@ -9,25 +13,25 @@ Introduction
The timer manager provides support for timer
facilities. The directives provided by the timer manager are:
-- ``rtems_timer_create`` - Create a timer
+- rtems_timer_create_ - Create a timer
-- ``rtems_timer_ident`` - Get ID of a timer
+- rtems_timer_ident_ - Get ID of a timer
-- ``rtems_timer_cancel`` - Cancel a timer
+- rtems_timer_cancel_ - Cancel a timer
-- ``rtems_timer_delete`` - Delete a timer
+- rtems_timer_delete_ - Delete a timer
-- ``rtems_timer_fire_after`` - Fire timer after interval
+- rtems_timer_fire_after_ - Fire timer after interval
-- ``rtems_timer_fire_when`` - Fire timer when specified
+- rtems_timer_fire_when_ - Fire timer when specified
-- ``rtems_timer_initiate_server`` - Initiate server for task-based timers
+- rtems_timer_initiate_server_ - Initiate server for task-based timers
-- ``rtems_timer_server_fire_after`` - Fire task-based timer after interval
+- rtems_timer_server_fire_after_ - Fire task-based timer after interval
-- ``rtems_timer_server_fire_when`` - Fire task-based timer when specified
+- rtems_timer_server_fire_when_ - Fire task-based timer when specified
-- ``rtems_timer_reset`` - Reset an interval timer
+- rtems_timer_reset_ - Reset an interval timer
Background
==========
@@ -40,65 +44,60 @@ A clock tick is required to support the functionality provided by this manager.
Timers
------
-A timer is an RTEMS object which allows the
-application to schedule operations to occur at specific times in
-the future. User supplied timer service routines are invoked by
-either the ``rtems_clock_tick`` directive or
-a special Timer Server task when the timer fires. Timer service
-routines may perform any operations or directives which normally
-would be performed by the application code which invoked the``rtems_clock_tick`` directive.
-
-The timer can be used to implement watchdog routines
-which only fire to denote that an application error has
-occurred. The timer is reset at specific points in the
-application to ensure that the watchdog does not fire. Thus, if
-the application does not reset the watchdog timer, then the
-timer service routine will fire to indicate that the application
-has failed to reach a reset point. This use of a timer is
-sometimes referred to as a "keep alive" or a "deadman" timer.
+A timer is an RTEMS object which allows the application to schedule operations
+to occur at specific times in the future. User supplied timer service routines
+are invoked by either the ``rtems_clock_tick`` directive or a special Timer
+Server task when the timer fires. Timer service routines may perform any
+operations or directives which normally would be performed by the application
+code which invoked the ``rtems_clock_tick`` directive.
+
+The timer can be used to implement watchdog routines which only fire to denote
+that an application error has occurred. The timer is reset at specific points
+in the application to ensure that the watchdog does not fire. Thus, if the
+application does not reset the watchdog timer, then the timer service routine
+will fire to indicate that the application has failed to reach a reset point.
+This use of a timer is sometimes referred to as a "keep alive" or a "deadman"
+timer.
Timer Server
------------
-The Timer Server task is responsible for executing the timer
-service routines associated with all task-based timers.
-This task executes at a priority higher than any RTEMS application
-task, and is created non-preemptible, and thus can be viewed logically as
-the lowest priority interrupt.
-
-By providing a mechanism where timer service routines execute
-in task rather than interrupt space, the application is
-allowed a bit more flexibility in what operations a timer
-service routine can perform. For example, the Timer Server
-can be configured to have a floating point context in which case
-it would be safe to perform floating point operations
-from a task-based timer. Most of the time, executing floating
-point instructions from an interrupt service routine
-is not considered safe. However, since the Timer Server task
-is non-preemptible, only directives allowed from an ISR can be
-called in the timer service routine.
-
-The Timer Server is designed to remain blocked until a
-task-based timer fires. This reduces the execution overhead
-of the Timer Server.
+The Timer Server task is responsible for executing the timer service routines
+associated with all task-based timers. This task executes at a priority higher
+than any RTEMS application task, and is created non-preemptible, and thus can
+be viewed logically as the lowest priority interrupt.
+
+By providing a mechanism where timer service routines execute in task rather
+than interrupt space, the application is allowed a bit more flexibility in what
+operations a timer service routine can perform. For example, the Timer Server
+can be configured to have a floating point context in which case it would be
+safe to perform floating point operations from a task-based timer. Most of the
+time, executing floating point instructions from an interrupt service routine
+is not considered safe. However, since the Timer Server task is
+non-preemptible, only directives allowed from an ISR can be called in the timer
+service routine.
+
+The Timer Server is designed to remain blocked until a task-based timer fires.
+This reduces the execution overhead of the Timer Server.
Timer Service Routines
----------------------
-The timer service routine should adhere to C calling
-conventions and have a prototype similar to the following:.. index:: rtems_timer_service_routine
+The timer service routine should adhere to C calling conventions and have a
+prototype similar to the following:
+
+.. index:: rtems_timer_service_routine
.. code:: c
rtems_timer_service_routine user_routine(
- rtems_id timer_id,
- void \*user_data
+ rtems_id timer_id,
+ void *user_data
);
-Where the timer_id parameter is the RTEMS object ID
-of the timer which is being fired and user_data is a pointer to
-user-defined information which may be utilized by the timer
-service routine. The argument user_data may be NULL.
+Where the timer_id parameter is the RTEMS object ID of the timer which is being
+fired and user_data is a pointer to user-defined information which may be
+utilized by the timer service routine. The argument user_data may be NULL.
Operations
==========
@@ -106,95 +105,89 @@ Operations
Creating a Timer
----------------
-The ``rtems_timer_create`` directive creates a timer by
-allocating a Timer Control Block (TMCB), assigning the timer a
-user-specified name, and assigning it a timer ID. Newly created
-timers do not have a timer service routine associated with them
-and are not active.
+The ``rtems_timer_create`` directive creates a timer by allocating a Timer
+Control Block (TMCB), assigning the timer a user-specified name, and assigning
+it a timer ID. Newly created timers do not have a timer service routine
+associated with them and are not active.
Obtaining Timer IDs
-------------------
-When a timer is created, RTEMS generates a unique
-timer ID and assigns it to the created timer until it is
-deleted. The timer ID may be obtained by either of two methods.
-First, as the result of an invocation of the``rtems_timer_create``
-directive, the timer ID is stored in a user provided location.
-Second, the timer ID may be obtained later using the``rtems_timer_ident`` directive. The timer ID
-is used by other directives to manipulate this timer.
+When a timer is created, RTEMS generates a unique timer ID and assigns it to
+the created timer until it is deleted. The timer ID may be obtained by either
+of two methods. First, as the result of an invocation of the
+``rtems_timer_create`` directive, the timer ID is stored in a user provided
+location. Second, the timer ID may be obtained later using the
+``rtems_timer_ident`` directive. The timer ID is used by other directives to
+manipulate this timer.
Initiating an Interval Timer
----------------------------
-The ``rtems_timer_fire_after``
-and ``rtems_timer_server_fire_after``
-directives initiate a timer to fire a user provided
-timer service routine after the specified
-number of clock ticks have elapsed. When the interval has
-elapsed, the timer service routine will be invoked from the``rtems_clock_tick`` directive if it was initiated
-by the ``rtems_timer_fire_after`` directive
-and from the Timer Server task if initiated by the``rtems_timer_server_fire_after`` directive.
+The ``rtems_timer_fire_after`` and ``rtems_timer_server_fire_after`` directives
+initiate a timer to fire a user provided timer service routine after the
+specified number of clock ticks have elapsed. When the interval has elapsed,
+the timer service routine will be invoked from the ``rtems_clock_tick``
+directive if it was initiated by the ``rtems_timer_fire_after`` directive and
+from the Timer Server task if initiated by the
+``rtems_timer_server_fire_after`` directive.
Initiating a Time of Day Timer
------------------------------
-The ``rtems_timer_fire_when``
-and ``rtems_timer_server_fire_when``
-directive initiate a timer to
-fire a user provided timer service routine when the specified
-time of day has been reached. When the interval has elapsed,
-the timer service routine will be invoked from the``rtems_clock_tick`` directive
-by the ``rtems_timer_fire_when`` directive
-and from the Timer Server task if initiated by the``rtems_timer_server_fire_when`` directive.
+The ``rtems_timer_fire_when`` and ``rtems_timer_server_fire_when`` directive
+initiate a timer to fire a user provided timer service routine when the
+specified time of day has been reached. When the interval has elapsed, the
+timer service routine will be invoked from the ``rtems_clock_tick`` directive
+by the ``rtems_timer_fire_when`` directive and from the Timer Server task if
+initiated by the ``rtems_timer_server_fire_when`` directive.
Canceling a Timer
-----------------
-The ``rtems_timer_cancel`` directive is used to halt the
-specified timer. Once canceled, the timer service routine will
-not fire unless the timer is reinitiated. The timer can be
-reinitiated using the ``rtems_timer_reset``,``rtems_timer_fire_after``, and``rtems_timer_fire_when`` directives.
+The ``rtems_timer_cancel`` directive is used to halt the specified timer. Once
+canceled, the timer service routine will not fire unless the timer is
+reinitiated. The timer can be reinitiated using the ``rtems_timer_reset``,
+``rtems_timer_fire_after``, and ``rtems_timer_fire_when`` directives.
Resetting a Timer
-----------------
-The ``rtems_timer_reset`` directive is used to restore an
-interval timer initiated by a previous invocation of``rtems_timer_fire_after`` or``rtems_timer_server_fire_after`` to
-its original interval length. If the
-timer has not been used or the last usage of this timer
-was by the ``rtems_timer_fire_when``
-or ``rtems_timer_server_fire_when``
-directive, then an error is returned. The timer service routine
-is not changed or fired by this directive.
+The ``rtems_timer_reset`` directive is used to restore an interval timer
+initiated by a previous invocation of ``rtems_timer_fire_after`` or
+``rtems_timer_server_fire_after`` to its original interval length. If the
+timer has not been used or the last usage of this timer was by the
+``rtems_timer_fire_when`` or ``rtems_timer_server_fire_when`` directive, then
+an error is returned. The timer service routine is not changed or fired by
+this directive.
Initiating the Timer Server
---------------------------
-The ``rtems_timer_initiate_server`` directive is used to
-allocate and start the execution of the Timer Server task. The
-application can specify both the stack size and attributes of the
-Timer Server. The Timer Server executes at a priority higher than
-any application task and thus the user can expect to be preempted
-as the result of executing the ``rtems_timer_initiate_server``
+The ``rtems_timer_initiate_server`` directive is used to allocate and start the
+execution of the Timer Server task. The application can specify both the stack
+size and attributes of the Timer Server. The Timer Server executes at a
+priority higher than any application task and thus the user can expect to be
+preempted as the result of executing the ``rtems_timer_initiate_server``
directive.
Deleting a Timer
----------------
-The ``rtems_timer_delete`` directive is used to delete a timer.
-If the timer is running and has not expired, the timer is
-automatically canceled. The timer's control block is returned
-to the TMCB free list when it is deleted. A timer can be
-deleted by a task other than the task which created the timer.
+The ``rtems_timer_delete`` directive is used to delete a timer. If the timer
+is running and has not expired, the timer is automatically canceled. The
+timer's control block is returned to the TMCB free list when it is deleted. A
+timer can be deleted by a task other than the task which created the timer.
Any subsequent references to the timer's name and ID are invalid.
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.
+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.
+
+.. _rtems_timer_create:
TIMER_CREATE - Create a timer
-----------------------------
@@ -207,29 +200,36 @@ TIMER_CREATE - Create a timer
.. code:: c
rtems_status_code rtems_timer_create(
- rtems_name name,
- rtems_id \*id
+ rtems_name name,
+ rtems_id *id
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - timer created successfully
-``RTEMS_INVALID_ADDRESS`` - ``id`` is NULL
-``RTEMS_INVALID_NAME`` - invalid timer name
-``RTEMS_TOO_MANY`` - too many timers created
+``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.
+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 not cause the calling task to be
-preempted.
+This directive will not cause the calling task to be preempted.
+
+.. _rtems_timer_ident:
TIMER_IDENT - Get ID of a timer
-------------------------------
@@ -242,29 +242,34 @@ TIMER_IDENT - Get ID of a timer
.. code:: c
rtems_status_code rtems_timer_ident(
- rtems_name name,
- rtems_id \*id
+ rtems_name name,
+ rtems_id *id
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - timer identified successfully
-``RTEMS_INVALID_ADDRESS`` - ``id`` is NULL
-``RTEMS_INVALID_NAME`` - timer name not found
+``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
+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.
+This directive will not cause the running task to be preempted.
+
+.. _rtems_timer_cancel:
TIMER_CANCEL - Cancel a timer
-----------------------------
@@ -277,23 +282,29 @@ TIMER_CANCEL - Cancel a timer
.. code:: c
rtems_status_code rtems_timer_cancel(
- rtems_id id
+ rtems_id id
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - timer canceled successfully
-``RTEMS_INVALID_ID`` - invalid timer id
+``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.
+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.
+.. _rtems_timer_delete:
+
TIMER_DELETE - Delete a timer
-----------------------------
.. index:: delete a timer
@@ -305,27 +316,30 @@ TIMER_DELETE - Delete a timer
.. code:: c
rtems_status_code rtems_timer_delete(
- rtems_id id
+ rtems_id id
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - timer deleted successfully
-``RTEMS_INVALID_ID`` - invalid timer id
+``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.
+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 not cause the running task to be
-preempted.
+This directive will not cause the running task to be preempted.
+
+A timer can be deleted by a task other than the task which created the timer.
-A timer can be deleted by a task other than the task
-which created the timer.
+.. _rtems_timer_fire_after:
TIMER_FIRE_AFTER - Fire timer after interval
--------------------------------------------
@@ -338,32 +352,38 @@ TIMER_FIRE_AFTER - Fire timer after interval
.. code:: c
rtems_status_code rtems_timer_fire_after(
- rtems_id id,
- rtems_interval ticks,
- rtems_timer_service_routine_entry routine,
- void \*user_data
+ rtems_id id,
+ rtems_interval ticks,
+ rtems_timer_service_routine_entry routine,
+ void *user_data
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - timer initiated successfully
-``RTEMS_INVALID_ADDRESS`` - ``routine`` is NULL
-``RTEMS_INVALID_ID`` - invalid timer id
-``RTEMS_INVALID_NUMBER`` - invalid interval
+``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.
+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.
+This directive will not cause the running task to be preempted.
+
+.. _rtems_timer_fire_when:
TIMER_FIRE_WHEN - Fire timer when specified
-------------------------------------------
@@ -376,34 +396,44 @@ TIMER_FIRE_WHEN - Fire timer when specified
.. code:: 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
+ rtems_id id,
+ rtems_time_of_day *wall_time,
+ rtems_timer_service_routine_entry routine,
+ void *user_data
);
**DIRECTIVE STATUS CODES:**
-``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_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.
+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.
+This directive will not cause the running task to be preempted.
+
+.. _rtems_timer_initiate_server:
TIMER_INITIATE_SERVER - Initiate server for task-based timers
-------------------------------------------------------------
@@ -416,32 +446,38 @@ TIMER_INITIATE_SERVER - Initiate server for task-based timers
.. code:: c
rtems_status_code rtems_timer_initiate_server(
- uint32_t priority,
- uint32_t stack_size,
- rtems_attribute attribute_set
+ uint32_t priority,
+ uint32_t stack_size,
+ rtems_attribute attribute_set
)
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - Timer Server initiated successfully
-``RTEMS_TOO_MANY`` - too many tasks created
+``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.
+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.
+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.
-Even through this directive invokes the ``rtems_task_create``
-and ``rtems_task_start`` directives, it should only fail
-due to resource allocation problems.
+.. _rtems_timer_server_fire_after:
TIMER_SERVER_FIRE_AFTER - Fire task-based timer after interval
--------------------------------------------------------------
@@ -454,35 +490,44 @@ TIMER_SERVER_FIRE_AFTER - Fire task-based timer after interval
.. code:: c
rtems_status_code rtems_timer_server_fire_after(
- rtems_id id,
- rtems_interval ticks,
- rtems_timer_service_routine_entry routine,
- void \*user_data
+ rtems_id id,
+ rtems_interval ticks,
+ rtems_timer_service_routine_entry routine,
+ void *user_data
);
**DIRECTIVE STATUS CODES:**
-``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
+``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.
+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.
+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.
+This directive will not cause the running task to be preempted.
+
+.. _rtems_timer_server_fire_when:
TIMER_SERVER_FIRE_WHEN - Fire task-based timer when specified
-------------------------------------------------------------
@@ -495,37 +540,50 @@ TIMER_SERVER_FIRE_WHEN - Fire task-based timer when specified
.. code:: 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
+ rtems_id id,
+ rtems_time_of_day *wall_time,
+ rtems_timer_service_routine_entry routine,
+ void *user_data
);
**DIRECTIVE STATUS CODES:**
-``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
+``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.
+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.
+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.
+This directive will not cause the running task to be preempted.
+
+.. _rtems_timer_reset:
TIMER_RESET - Reset an interval timer
-------------------------------------
@@ -538,45 +596,36 @@ TIMER_RESET - Reset an interval timer
.. code:: c
rtems_status_code rtems_timer_reset(
- rtems_id id
+ rtems_id id
);
**DIRECTIVE STATUS CODES:**
-``RTEMS_SUCCESSFUL`` - timer reset successfully
-``RTEMS_INVALID_ID`` - invalid timer id
-``RTEMS_NOT_DEFINED`` - attempted to reset a when or newly created timer
+``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````rtems_timer_server_fire_after``
-directive used.
+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.
+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.
+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.
-
-.. COMMENT: COPYRIGHT (c) 1988-2013.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-.. COMMENT: Open Issues
-
-.. COMMENT: - nicen up the tables
-
-.. COMMENT: - use math mode to print formulas
-