/* Quagga timers support -- header
 * Copyright (C) 2009 Chris Hall (GMCH), Highwayman
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2, or (at your
 * option) any later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef _ZEBRA_QTIMERS_H
#define _ZEBRA_QTIMERST_H

#include "zassert.h"
#include "qtime.h"
#include "heap.h"

#ifndef Inline
#define Inline static inline
#endif

/*==============================================================================
 * Quagga Timers -- qtimer_xxxx
 *
 * Here and in qtimers.c is a data structure for managing multiple timers
 * each with an action to be executed when the timer expires.
 */

/*==============================================================================
 * Data Structures.
 */

typedef struct qtimer*       qtimer ;
typedef struct qtimer_pile*  qtimer_pile ;

typedef void (qtimer_action)(qtimer qtr, void* timer_info, qtime_t when) ;

struct qtimer
{
  qtimer_pile     pile ;
  heap_backlink_t backlink ;

  int             active ;      /* timer is active in the current pile.  */

  qtime_t         time ;
  qtimer_action*  action ;
  void*           timer_info ;
} ;

struct qtimer_pile
{
  struct heap   timers ;

  qtimer        unset_pending ;
} ;

/*==============================================================================
 * Functions
 */

qtimer_pile
qtimer_pile_init_new(qtimer_pile qtp) ;

int
qtimer_pile_dispatch_next(qtimer_pile qtp, qtime_t upto) ;

qtimer
qtimer_pile_ream(qtimer_pile qtp, int free_structure) ;

Inline qtime_t
qtimer_time_now() ;

Inline qtime_t
qtimer_time_future(qtime_t interval) ;

Inline qtime_t
qtimer_time_from_realtime(qtime_t realtime) ;

Inline qtime_t
qtimer_time_from_timeofday(qtime_t timeofday) ;

qtimer
qtimer_init_new(qtimer qtr, qtimer_pile qtp,
                                      qtimer_action* action, void* timer_info) ;
void
qtimer_set_pile(qtimer qtr, qtimer_pile qtp) ;

void
qtimer_set_action(qtimer qtr, qtimer_action* action) ;

void
qtimer_set_info(qtimer qtr, void* timer_info) ;

void
qtimer_free(qtimer qtr) ;

void
qtimer_set(qtimer qtr, qtime_t when) ;

void
qtimer_unset(qtimer qtr) ;

Inline void
qtimer_add(qtimer qtr, qtime_t interval) ;

Inline qtime_t
qtimer_get(qtimer qtr) ;

/*==============================================================================
 * Inline functions
 */

/* The current time according to the qtimer time-base (monotonic time).
 */
Inline qtime_t
qtimer_time_now()
{
  return qt_get_monotonic() ;
}

/* What the qtimer time will be 'interval' qtime_t units from now..
 */
Inline qtime_t
qtimer_time_future(qtime_t interval)
{
  return qtimer_time_now() + interval ;
} ;

/* Get a qtimer time from a CLOCK_REALTIME time
 */
Inline qtime_t
qtimer_time_from_realtime(qtime_t realtime)
{
  return qt_realtime2monotonic(realtime) ;
} ;

/* Get a qtimer time from a gettimeofday() time   (in case != CLOCK_REALTIME)
 */
Inline qtime_t
qtimer_time_from_timeofday(qtime_t timeofday)
{
  return qt_timeofday2monotonic(timeofday) ;
} ;

/* Set given timer to given time later than *its* current time.
 */
Inline void
qtimer_add(qtimer qtr, qtime_t interval)
{
  qtimer_set(qtr, qtimer_get(qtr) + interval);
} ;

/* Get the given timer's time.
 */
Inline qtime_t
qtimer_get(qtimer qtr)
{
  return qtr->time ;
} ;

#endif /* _ZEBRA_QPSELECT_H */