source: rtems/cpukit/rtems/include/rtems/rtems/timerimpl.h @ 4cd55724

/**
 * @file
 *
 * @ingroup ClassicTimerImpl
 *
 * @brief Classic Timer Implementation
 */

/*
 * COPYRIGHT (c) 1989-2011.
 * 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.org/license/LICENSE.
 */

#ifndef _RTEMS_RTEMS_TIMER_INL
#define _RTEMS_RTEMS_TIMER_INL

#include <rtems/rtems/timer.h>
#include <rtems/score/objectimpl.h>
#include <rtems/score/thread.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup ClassicTimerImpl Classic Timer Implementation
 *
 * @ingroup ClassicTimer
 *
 * @{
 */

/**
 *  @brief Instantiate RTEMS Timer Data
 *
 *  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

typedef struct Timer_server_Control Timer_server_Control;

/**
 * @brief Method used to schedule the insertion of task based timers.
 */
typedef void (*Timer_server_Schedule_operation)(
  Timer_server_Control *timer_server,
  Timer_Control        *timer
);

typedef struct {
  /**
   * @brief This watchdog that will be registered in the system tick mechanic
   * for timer server wake-up.
   */
  Watchdog_Control System_watchdog;

  /**
   * @brief Chain for watchdogs which will be triggered by the timer server.
   */
  Chain_Control Chain;

  /**
   * @brief Last known time snapshot of the timer server.
   *
   * The units may be ticks or seconds.
   */
  Watchdog_Interval volatile last_snapshot;
} Timer_server_Watchdogs;

struct Timer_server_Control {
  /**
   * @brief Timer server thread.
   */
  Thread_Control *thread;

  /**
   * @brief The schedule operation method of the timer server.
   */
  Timer_server_Schedule_operation schedule_operation;

  /**
   * @brief Interval watchdogs triggered by the timer server.
   */
  Timer_server_Watchdogs Interval_watchdogs;

  /**
   * @brief TOD watchdogs triggered by the timer server.
   */
  Timer_server_Watchdogs TOD_watchdogs;

  /**
   * @brief Chain of timers scheduled for insert.
   *
   * This pointer is not @c NULL whenever the interval and TOD chains are
   * processed.  After the processing this list will be checked and if
   * necessary the processing will be restarted.  Processing of these chains
   * can be only interrupted through interrupts.
   */
  Chain_Control *volatile insert_chain;

  /**
   * @brief Indicates that the timer server is active or not.
   *
   * The server is active after the delay on a system watchdog.  The activity
   * period of the server ends when no more watchdogs managed by the server
   * fire.  The system watchdogs must not be manipulated when the server is
   * active.
   */
  bool volatile active;
};

/**
 * @brief Pointer to default timer server control block.
 *
 * This value is @c NULL when the default timer server is not initialized.
 */
RTEMS_TIMER_EXTERN Timer_server_Control *volatile _Timer_server;

/**
 *  The following defines the information control block used to manage
 *  this class of objects.
 */
RTEMS_TIMER_EXTERN Objects_Information  _Timer_Information;

/**
 *  @brief Timer Manager Initialization
 *
 *  This routine performs the initialization necessary for this manager.
 */
void _Timer_Manager_initialization(void);

/**
 *  @brief Timer_Allocate
 *
 *  This function allocates a timer control block from
 *  the inactive chain of free timer control blocks.
 */
RTEMS_INLINE_ROUTINE Timer_Control *_Timer_Allocate( void )
{
  return (Timer_Control *) _Objects_Allocate( &_Timer_Information );
}

/**
 *  @brief Timer_Free
 *
 *  This routine frees a timer control block to the
 *  inactive chain of free timer control blocks.
 */
RTEMS_INLINE_ROUTINE void _Timer_Free (
  Timer_Control *the_timer
)
{
  _Objects_Free( &_Timer_Information, &the_timer->Object );
}

/**
 *  @brief Timer_Get
 *
 *  This function maps timer IDs to timer control blocks.
 *  If ID corresponds to a local timer, then it returns
 *  the timer control pointer which maps to ID and location
 *  is set to OBJECTS_LOCAL.  Otherwise, location is set
 *  to OBJECTS_ERROR and the returned value is undefined.
 */
RTEMS_INLINE_ROUTINE Timer_Control *_Timer_Get (
  Objects_Id         id,
  Objects_Locations *location
)
{
  return (Timer_Control *)
    _Objects_Get( &_Timer_Information, id, location );
}

/**
 *  @brief Timer_Is_interval_class
 *
 *  This function returns TRUE if the class is that of an INTERVAL
 *  timer, and FALSE otherwise.
 */
RTEMS_INLINE_ROUTINE bool _Timer_Is_interval_class (
  Timer_Classes the_class
)
{
  return (the_class == TIMER_INTERVAL) || (the_class == TIMER_INTERVAL_ON_TASK);
}

/**
 *  @brief Timer_Is_time_of_day_class
 *
 *  This function returns TRUE if the class is that of an INTERVAL
 *  timer, and FALSE otherwise.
 */
RTEMS_INLINE_ROUTINE bool _Timer_Is_timer_of_day_class (
  Timer_Classes the_class
)
{
  return ( the_class == TIMER_TIME_OF_DAY );
}

/**
 *  @brief Timer_Is_dormant_class
 *
 *  This function returns TRUE if the class is that of a DORMANT
 *  timer, and FALSE otherwise.
 */
RTEMS_INLINE_ROUTINE bool _Timer_Is_dormant_class (
  Timer_Classes the_class
)
{
  return ( the_class == TIMER_DORMANT );
}

/**@}*/

#ifdef __cplusplus
}
#endif

#endif
/* end of include file */