The Timer Manager provides support for timer facilities. More...

Data Structures
struct	rtems_timer_information
	The structure contains information about a timer. More...

Macros
#define	TIMER_CLASS_BIT_NOT_DORMANT 0x4
	This timer class bit indicates that the timer is not dormant.

#define	TIMER_CLASS_BIT_ON_TASK 0x2
	This timer class bit indicates that the timer routine executes in a task context.

#define	TIMER_CLASS_BIT_TIME_OF_DAY 0x1
	This timer class bit indicates that the timer uses a time of day.

#define	RTEMS_TIMER_SERVER_DEFAULT_PRIORITY ( (rtems_task_priority) -1 )
	This constant represents the default value for the task priority of the Timer Server.

Typedefs
typedef void	rtems_timer_service_routine
	This type defines the return type of routines which can be fired by directives of the Timer Manager.

typedef rtems_timer_service_routine(*	rtems_timer_service_routine_entry) (rtems_id, void *)
	This type defines the prototype of routines which can be fired by directives of the Timer Manager.

Enumerations
enum	Timer_Classes { TIMER_DORMANT , TIMER_INTERVAL = TIMER_CLASS_BIT_NOT_DORMANT , TIMER_INTERVAL_ON_TASK , TIMER_TIME_OF_DAY , TIMER_TIME_OF_DAY_ON_TASK }
	The timer class indicates how the timer was most recently fired. More...

Functions
rtems_status_code	rtems_timer_get_information (rtems_id id, rtems_timer_information *the_info)
	Gets information about the timer.

rtems_status_code	rtems_timer_create (rtems_name name, rtems_id *id)
	Creates a timer.

rtems_status_code	rtems_timer_ident (rtems_name name, rtems_id *id)
	Identifies a timer by the object name.

rtems_status_code	rtems_timer_cancel (rtems_id id)
	Cancels the timer.

rtems_status_code	rtems_timer_delete (rtems_id id)
	Deletes the timer.

rtems_status_code	rtems_timer_fire_after (rtems_id id, rtems_interval ticks, rtems_timer_service_routine_entry routine, void *user_data)
	Fires the timer after the interval.

rtems_status_code	rtems_timer_fire_when (rtems_id id, const rtems_time_of_day wall_time, rtems_timer_service_routine_entry routine, void user_data)
	Fires the timer at the time of day.

rtems_status_code	rtems_timer_initiate_server (rtems_task_priority priority, size_t stack_size, rtems_attribute attribute_set)
	Initiates the Timer Server.

rtems_status_code	rtems_timer_server_fire_after (rtems_id id, rtems_interval ticks, rtems_timer_service_routine_entry routine, void *user_data)
	Fires the timer after the interval using the Timer Server.

rtems_status_code	rtems_timer_server_fire_when (rtems_id id, const rtems_time_of_day wall_time, rtems_timer_service_routine_entry routine, void user_data)
	Fires the timer at the time of day using the Timer Server.

rtems_status_code	rtems_timer_reset (rtems_id id)
	Resets the timer.

Detailed Description

The Timer Manager provides support for timer facilities.

Macro Definition Documentation

◆ RTEMS_TIMER_SERVER_DEFAULT_PRIORITY

#define RTEMS_TIMER_SERVER_DEFAULT_PRIORITY ( (rtems_task_priority) -1 )

This constant represents the default value for the task priority of the Timer Server.

When given this priority, a special high priority not accessible via the Classic API is used.

Typedef Documentation

◆ rtems_timer_service_routine

typedef void rtems_timer_service_routine

This type defines the return type of routines which can be fired by directives of the Timer Manager.

This type can be used to document timer service routines in the source code.

Enumeration Type Documentation

◆ Timer_Classes

enum Timer_Classes

The timer class indicates how the timer was most recently fired.

Enumerator
TIMER_DORMANT	This timer class indicates that the timer was never in use.
TIMER_INTERVAL	This timer class indicates that the timer is currently in use as an interval timer which will fire in the context of the clock tick ISR.
TIMER_INTERVAL_ON_TASK	This timer class indicates that the timer is currently in use as an interval timer which will fire in the context of the Timer Server task.
TIMER_TIME_OF_DAY	This timer class indicates that the timer is currently in use as an time of day timer which will fire in the context of the clock tick ISR.
TIMER_TIME_OF_DAY_ON_TASK	This timer class indicates that the timer is currently in use as an time of day timer which will fire in the context of the Timer Server task.

Function Documentation

◆ rtems_timer_cancel()

rtems_status_code rtems_timer_cancel ( rtems_id id )

Cancels the timer.

Parameters

id	is the timer identifier.

This directive cancels the timer specified by id. This timer will be reinitiated by the next invocation of rtems_timer_reset(), rtems_timer_fire_after(), rtems_timer_fire_when(), rtems_timer_server_fire_after(), or rtems_timer_server_fire_when() with the same timer identifier.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_create()

rtems_status_code rtems_timer_create	(	rtems_name	name,
		rtems_id *	id
	)

Creates a timer.

Parameters

	name	is the object name of the timer.
[out]	id	is the pointer to an rtems_id object. When the directive call is successful, the identifier of the created timer will be stored in this object.

This directive creates a timer which resides on the local node. The timer has the user-defined object name specified in name. The assigned object identifier is returned in id. This identifier is used to access the timer with other timer related directives.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_NAME	The `name` parameter was invalid.
RTEMS_INVALID_ADDRESS	The `id` parameter was NULL.
RTEMS_TOO_MANY	There was no inactive object available to create a timer. The number of timers available to the application is configured through the CONFIGURE_MAXIMUM_TIMERS application configuration option.

Notes

The processor used to maintain the timer is the processor of the calling task at some point during the timer creation.

For control and maintenance of the timer, RTEMS allocates a TMCB from the local TMCB free pool and initializes it.

Constraints

The following constraints apply to this directive:

The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive may obtain and release the object allocator mutex. This may cause the calling task to be preempted.
The number of timers available to the application is configured through the CONFIGURE_MAXIMUM_TIMERS application configuration option.
Where the object class corresponding to the directive is configured to use unlimited objects, the directive may allocate memory from the RTEMS Workspace.

◆ rtems_timer_delete()

rtems_status_code rtems_timer_delete ( rtems_id id )

Deletes the timer.

Parameters

id	is the timer identifier.

This directive deletes the timer specified by id. If the timer is running, it is automatically canceled.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Notes: The TMCB for the deleted timer is reclaimed by RTEMS.

Constraints

The following constraints apply to this directive:

The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive may obtain and release the object allocator mutex. This may cause the calling task to be preempted.
The calling task does not have to be the task that created the object. Any local task that knows the object identifier can delete the object.
Where the object class corresponding to the directive is configured to use unlimited objects, the directive may free memory to the RTEMS Workspace.

◆ rtems_timer_fire_after()

rtems_status_code rtems_timer_fire_after	(	rtems_id	id,
		rtems_interval	ticks,
		rtems_timer_service_routine_entry	routine,
		void *	user_data
	)

Fires the timer after the interval.

Parameters

id	is the timer identifier.
ticks	is the interval until the routine is fired in clock ticks.
routine	is the routine to schedule.
user_data	is the argument passed to the routine when it is fired.

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 of clock ticks has passed specified by ticks. When the timer fires, the timer service routine routine will be invoked with the argument user_data in the context of the clock tick ISR.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_NUMBER	The `ticks` parameter was 0.
RTEMS_INVALID_ADDRESS	The `routine` parameter was NULL.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_fire_when()

rtems_status_code rtems_timer_fire_when	(	rtems_id	id,
		const rtems_time_of_day *	wall_time,
		rtems_timer_service_routine_entry	routine,
		void *	user_data
	)

Fires the timer at the time of day.

Parameters

id	is the timer identifier.
wall_time	is the time of day when the routine is fired.
routine	is the routine to schedule.
user_data	is the argument passed to the routine when it is fired.

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 in the context of the clock tick ISR.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_NOT_DEFINED	The system date and time was not set.
RTEMS_INVALID_ADDRESS	The `routine` parameter was NULL.
RTEMS_INVALID_ADDRESS	The `wall_time` parameter was NULL.
RTEMS_INVALID_CLOCK	The time of day was invalid.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_get_information()

rtems_status_code rtems_timer_get_information	(	rtems_id	id,
		rtems_timer_information *	the_info
	)

Gets information about the timer.

Parameters

	id	is the timer identifier.
[out]	the_info	is the pointer to an rtems_timer_information object. When the directive call is successful, the information about the timer will be stored in this object.

This directive returns information about the timer.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_ADDRESS	The `the_info` parameter was NULL.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_ident()

rtems_status_code rtems_timer_ident	(	rtems_name	name,
		rtems_id *	id
	)

Identifies a timer by the object name.

Parameters

	name	is the object name to look up.
[out]	id	is the pointer to an rtems_id object. When the directive call is successful, the object identifier of an object with the specified name will be stored in this object.

This directive obtains a timer identifier associated with the timer name specified in name.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_ADDRESS	The `id` parameter was NULL.
RTEMS_INVALID_NAME	The `name` parameter was 0.
RTEMS_INVALID_NAME	There was no object with the specified name on the local node.

Notes

If the timer name is not unique, then the timer identifier will match the first timer with that name in the search order. However, this timer identifier is not guaranteed to correspond to the desired timer.

The objects are searched from lowest to the highest index. Only the local node is searched.

The timer identifier is used with other timer related directives to access the timer.

Constraints

The following constraints apply to this directive:

The directive may be called from within any runtime context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_initiate_server()

rtems_status_code rtems_timer_initiate_server	(	rtems_task_priority	priority,
		size_t	stack_size,
		rtems_attribute	attribute_set
	)

Initiates the Timer Server.

Parameters

priority	is the task priority.
stack_size	is the task stack size in bytes.
attribute_set	is the task attribute set.

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.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INCORRECT_STATE	The Timer Server was already initiated.
RTEMS_INVALID_PRIORITY	The task priority was invalid.
RTEMS_TOO_MANY	There was no inactive task object available to create the Timer Server task.
RTEMS_UNSATISFIED	There was not enough memory to allocate the task storage area. The task storage area contains the task stack, the thread-local storage, and the floating point context.
RTEMS_UNSATISFIED	One of the task create extensions failed to create the Timer Server task.

Notes: The Timer Server task is created using the rtems_task_create() directive and must be accounted for when configuring the system.

Constraints

The following constraints apply to this directive:

The directive may obtain and release the object allocator mutex. This may cause the calling task to be preempted.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The number of timers available to the application is configured through the CONFIGURE_MAXIMUM_TIMERS application configuration option.
Where the object class corresponding to the directive is configured to use unlimited objects, the directive may allocate memory from the RTEMS Workspace.

◆ rtems_timer_reset()

rtems_status_code rtems_timer_reset ( rtems_id id )

Resets the timer.

Parameters

id	is the timer identifier.

This directive resets the timer specified by 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.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.
RTEMS_NOT_DEFINED	The timer was not of the interval class.

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.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_server_fire_after()

rtems_status_code rtems_timer_server_fire_after	(	rtems_id	id,
		rtems_interval	ticks,
		rtems_timer_service_routine_entry	routine,
		void *	user_data
	)

Fires the timer after the interval using the Timer Server.

Parameters

id	is the timer identifier.
ticks	is the interval until the routine is fired in clock ticks.
routine	is the routine to schedule.
user_data	is the argument passed to the routine when it is fired.

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 of clock ticks has passed specified by ticks. When the timer fires, the timer service routine routine will be invoked with the argument user_data in the context of the Timer Server task.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INCORRECT_STATE	The Timer Server was not initiated.
RTEMS_INVALID_NUMBER	The `ticks` parameter was 0.
RTEMS_INVALID_ADDRESS	The `routine` parameter was NULL.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_timer_server_fire_when()

rtems_status_code rtems_timer_server_fire_when	(	rtems_id	id,
		const rtems_time_of_day *	wall_time,
		rtems_timer_service_routine_entry	routine,
		void *	user_data
	)

Fires the timer at the time of day using the Timer Server.

Parameters

id	is the timer identifier.
wall_time	is the time of day when the routine is fired.
routine	is the routine to schedule.
user_data	is the argument passed to the routine when it is fired.

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 in the context of the Timer Server task.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INCORRECT_STATE	The Timer Server was not initiated.
RTEMS_NOT_DEFINED	The system date and time was not set.
RTEMS_INVALID_ADDRESS	The `routine` parameter was NULL.
RTEMS_INVALID_ADDRESS	The `wall_time` parameter was NULL.
RTEMS_INVALID_CLOCK	The time of day was invalid.
RTEMS_INVALID_ID	There was no timer associated with the identifier specified by `id`.

Constraints

The following constraints apply to this directive:

The directive may be called from within interrupt context.
The directive may be called from within device driver initialization context.
The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ RTEMS_TIMER_SERVER_DEFAULT_PRIORITY

Typedef Documentation

◆ rtems_timer_service_routine

Enumeration Type Documentation

◆ Timer_Classes

Function Documentation

◆ rtems_timer_cancel()

◆ rtems_timer_create()

◆ rtems_timer_delete()

◆ rtems_timer_fire_after()

◆ rtems_timer_fire_when()

◆ rtems_timer_get_information()

◆ rtems_timer_ident()

◆ rtems_timer_initiate_server()

◆ rtems_timer_reset()

◆ rtems_timer_server_fire_after()

◆ rtems_timer_server_fire_when()