/**
* @file rtems/rtems/timer.h
*
* This include file contains all the constants, structures, and
* prototypes associated with the Timer Manager. This manager provides
* facilities to configure, initiate, cancel, and delete timers which will
* fire at specified intervals of time.
*
* Directives provided are:
*
* - create a timer
* - get an ID of a timer
* - delete a timer
* - set timer to fire in context of clock tick
* - after a number of ticks have passed
* - when a specified date and time has been reached
* - initiate the timer server task
* - set timer to fire in context of the timer server task
* - after a number of ticks have passed
* - when a specified date and time has been reached
* - reset a timer
* - cancel a time
*/
/* COPYRIGHT (c) 1989-2008.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#ifndef _RTEMS_RTEMS_TIMER_H
#define _RTEMS_RTEMS_TIMER_H
/**
* This constant is defined to extern most of the time when using
* this header file. However by defining it to nothing, the data
* declared in this header file can be instantiated. This is done
* in a single per manager file.
*/
#ifndef RTEMS_TIMER_EXTERN
#define RTEMS_TIMER_EXTERN extern
#endif
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/score/object.h>
#include <rtems/score/watchdog.h>
#include <rtems/score/thread.h>
#include <rtems/rtems/clock.h>
#include <rtems/rtems/attr.h>
/**
* @defgroup ClassicTimer Classic API Timer
*
* This encapsulates functionality which XXX
*/
/**@{*/
/**
* The following enumerated type details the classes to which a timer
* may belong.
*/
typedef enum {
/**
* This value indicates the timer is currently in use as an interval
* timer which will fire in the clock tick ISR.
*/
TIMER_INTERVAL,
/**
* This value indicates the timer is currently in use as an interval
* timer which will fire in the timer server task.
*/
TIMER_INTERVAL_ON_TASK,
/**
* This value indicates the timer is currently in use as an time of day
* timer which will fire in the clock tick ISR.
*/
TIMER_TIME_OF_DAY,
/**
* This value indicates the timer is currently in use as an time of day
* timer which will fire in the timer server task.
*/
TIMER_TIME_OF_DAY_ON_TASK,
/**
* This value indicates the timer is currently not in use.
*/
TIMER_DORMANT
} Timer_Classes;
/**
* The following types define a pointer to a timer service routine.
*/
typedef void rtems_timer_service_routine;
/**
* This type defines the type used to manage and indirectly invoke
* Timer Service Routines (TSRs). This defines the prototype and interface
* for a function which is to be used as a TSR.
*/
typedef rtems_timer_service_routine ( *rtems_timer_service_routine_entry )(
rtems_id,
void *
);
/**
* The following defines the information control block used to manage
* this class of objects.
*/
RTEMS_TIMER_EXTERN Objects_Information _Timer_Information;
/**
* Pointer to TCB of the Timer Server. This is NULL before the
* server is executing and task-based timers are not allowed to be
* initiated until the server is started.
*/
RTEMS_TIMER_EXTERN Thread_Control *_Timer_Server;
/**
* This chain contains the list of interval timers that are
* executed in the context of the Timer Server.
*
* @note This is extern'ed because they do not have to be in the
* minimum footprint. It is only really required when
* task-based timers are used. Since task-based timers can
* not be started until the server is initiated, this structure
* does not have to be initialized until then. This is declared
* in the same file as _Timer_Server_body.
*/
extern Chain_Control _Timer_Ticks_chain;
/**
* This chain contains the list of time of day timers that are
* executed in the context of the Timer Server.
*
* @note This is extern'ed because they do not have to be in the
* minimum footprint. It is only really required when
* task-based timers are used. Since task-based timers can
* not be started until the server is initiated, this structure
* does not have to be initialized until then. This is declared
* in the same file as _Timer_Server_body.
*/
extern Chain_Control _Timer_Seconds_chain;
/**
* The following records define the control block used to manage
* each timer.
*/
typedef struct {
/** This field is the object management portion of a Timer instance. */
Objects_Control Object;
/** This field is the Watchdog instance which will be the scheduled. */
Watchdog_Control Ticker;
/** This field indicates what type of timer this currently is. */
Timer_Classes the_class;
} Timer_Control;
/**
* @brief _Timer_Manager_initialization
*
* This routine performs the initialization necessary for this manager.
*/
void _Timer_Manager_initialization(
uint32_t maximum_timers
);
/**
* @brief _Timer_Server_body
*
* This is the server for task based timers. This task executes whenever
* a task-based timer should fire. It services both "after" and "when"
* timers. It is not created automatically but must be created explicitly
* by the application before task-based timers may be initiated.
*/
Thread _Timer_Server_body(
uint32_t ignored
);
/**
* @brief rtems_timer_create
*
* This routine implements the rtems_timer_create directive. The
* timer will have the name name. It returns the id of the
* created timer in ID.
*/
rtems_status_code rtems_timer_create(
rtems_name name,
Objects_Id *id
);
/**
* @brief rtems_timer_ident
*
* This routine implements the rtems_timer_ident directive.
* This directive returns the timer ID associated with name.
* If more than one timer is named name, then the timer
* to which the ID belongs is arbitrary.
*/
rtems_status_code rtems_timer_ident(
rtems_name name,
Objects_Id *id
);
/**
* @brief rtems_timer_cancel
*
* This routine implements the rtems_timer_cancel directive. It is used
* to stop the timer associated with ID from firing.
*/
rtems_status_code rtems_timer_cancel(
Objects_Id id
);
/**
* @brief rtems_timer_delete
*
* This routine implements the rtems_timer_delete directive. The
* timer indicated by ID is deleted.
*/
rtems_status_code rtems_timer_delete(
Objects_Id id
);
/**
* @brief rtems_timer_fire_after
*
* This routine implements the rtems_timer_fire_after directive. It
* initiates the timer associated with ID to fire in ticks clock ticks.
* When the timer fires, the routine will be invoked in the context
* of the rtems_clock_tick directive which is normally invoked as
* part of servicing a periodic interupt.
*/
rtems_status_code rtems_timer_fire_after(
Objects_Id id,
rtems_interval ticks,
rtems_timer_service_routine_entry routine,
void *user_data
);
/**
* @brief rtems_timer_server_fire_after
*
* This routine implements the rtems_timer_server_fire_after directive. It
* initiates the timer associated with ID to fire in ticks clock
* ticks. When the timer fires, the routine will be invoked by the
* Timer Server in the context of a task NOT IN THE CONTEXT of the
* clock tick interrupt.
*/
rtems_status_code rtems_timer_server_fire_after(
Objects_Id id,
rtems_interval ticks,
rtems_timer_service_routine_entry routine,
void *user_data
);
/**
* @brief rtems_timer_fire_when
*
* This routine implements the rtems_timer_fire_when directive. It
* initiates the timer associated with ID to fire at wall_time
* When the timer fires, the routine will be invoked in the context
* of the rtems_clock_tick directive which is normally invoked as
* part of servicing a periodic interupt.
*/
rtems_status_code rtems_timer_fire_when(
Objects_Id id,
rtems_time_of_day *wall_time,
rtems_timer_service_routine_entry routine,
void *user_data
);
/**
* @brief rtems_timer_server_fire_when
*
* This routine implements the rtems_timer_server_fire_when directive. It
* initiates the timer associated with ID to fire at wall_time
* When the timer fires, the routine will be invoked by the
* Timer Server in the context of a task NOT IN THE CONTEXT of the
* clock tick interrupt.
*/
rtems_status_code rtems_timer_server_fire_when(
Objects_Id id,
rtems_time_of_day *wall_time,
rtems_timer_service_routine_entry routine,
void *user_data
);
/**
* @brief rtems_timer_reset
*
* This routine implements the rtems_timer_reset directive. It is used
* to reinitialize the interval timer associated with ID just as if
* rtems_timer_fire_after were re-invoked with the same arguments that
* were used to initiate this timer.
*/
rtems_status_code rtems_timer_reset(
Objects_Id id
);
/**
* @brief rtems_timer_initiate_server
*
* This routine implements the rtems_timer_initiate_server directive.
* It creates and starts the server that executes task-based timers.
* It must be invoked before any task-based timers can be initiated.
*/
rtems_status_code rtems_timer_initiate_server(
uint32_t priority,
uint32_t stack_size,
rtems_attribute attribute_set
);
/**
* This is the default value for the priority of the Timer Server.
* When given this priority, a special high priority not accessible
* via the Classic API is used.
*/
#define RTEMS_TIMER_SERVER_DEFAULT_PRIORITY -1
/**
* This is the structure filled in by the timer get information
* service.
*/
typedef struct {
/** This indicates the current type of the timer. */
Timer_Classes the_class;
/** This indicates the initial requested interval. */
Watchdog_Interval initial;
/** This indicates the time the timer was initially scheduled. */
Watchdog_Interval start_time;
/** This indicates the time the timer is scheduled to fire. */
Watchdog_Interval stop_time;
} rtems_timer_information;
/**
* @brief rtems_timer_get_information
*
* This routine implements the rtems_timer_get_information directive.
* This directive returns information about the timer.
*/
rtems_status_code rtems_timer_get_information(
Objects_Id id,
rtems_timer_information *the_info
);
/**
* Macros and routines that expose the mechanisms required to service
* the Timer Server timer. These stop the timer, synchronize it with
* the current time, and restart it.
*/
extern Watchdog_Control _Timer_Seconds_timer;
/**
* This method is used to temporarily disable updates to the
* Ticks Timer Chain managed by the Timer Server.
*/
#define _Timer_Server_stop_ticks_timer() \
_Watchdog_Remove( &_Timer_Server->Timer )
/**
* This method is used to temporarily disable updates to the
* Seconds Timer Chain managed by the Timer Server.
*/
#define _Timer_Server_stop_seconds_timer() \
_Watchdog_Remove( &_Timer_Seconds_timer );
/**
* This is a helper function which processes the ticks chain when
* needed. It advances time for the ticks chain which results in
* timers firing.
*/
void _Timer_Server_process_ticks_chain(void);
/**
* This is a helper function which processes the seconds chain when
* needed. It advances time for the seconds chain which results in
* timers firing.
*/
void _Timer_Server_process_seconds_chain(void);
/**
* This method resets a timer and places it on the Ticks chain. It
* is assumed that the timer has already been canceled.
*/
#define _Timer_Server_reset_ticks_timer() \
do { \
if ( !_Chain_Is_empty( &_Timer_Ticks_chain ) ) { \
_Watchdog_Insert_ticks( &_Timer_Server->Timer, \
((Watchdog_Control *)_Timer_Ticks_chain.first)->delta_interval ); \
} \
} while (0)
/**
* This method resets a timer and places it on the Seconds chain. It
* is assumed that the timer has already been canceled.
*/
#define _Timer_Server_reset_seconds_timer() \
do { \
if ( !_Chain_Is_empty( &_Timer_Seconds_chain ) ) { \
_Watchdog_Insert_seconds( &_Timer_Seconds_timer, \
((Watchdog_Control *)_Timer_Seconds_chain.first)->delta_interval ); \
} \
} while (0)
#ifndef __RTEMS_APPLICATION__
#include <rtems/rtems/timer.inl>
#endif
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
