include/input/GP_Timer.h

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2013 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23 /*
  24
  25   Timers and priority queue implementation.
  26
  27  */
  28
  29 #ifndef INPUT_GP_TIMER_H
  30 #define INPUT_GP_TIMER_H
  31
  32 #include <stdint.h>
  33
  34 typedef struct GP_Timer {
  35         /* Heap pointers and number of sons */
  36         struct GP_Timer *left;
  37         struct GP_Timer *right;
  38         unsigned int sons;
  39
  40         /* Expiration time */
  41         uint64_t expires;
  42         /*
  43          * If not zero return value from Callback is ignored and
  44          * timer is rescheduled each time it expires.
  45          */
  46         uint32_t period;
  47
  48         /* Timer id, showed in debug messages */
  49         char id[10];
  50
  51         /*
  52          * Timer Callback
  53          *
  54          * If non-zero is returned, the timer is rescheduled to expire
  55          * return value from now.
  56          */
  57         uint32_t (*Callback)(struct GP_Timer *self);
  58         void *priv;
  59 } GP_Timer;
  60
  61 #define GP_TIMER_DECLARE(name, texpires, tperiod, tid, tCallback, tpriv) \
  62         GP_Timer name = { \
  63                 .expires = texpires, \
  64                 .period = tperiod, \
  65                 .id = tid, \
  66                 .Callback = tCallback, \
  67                 .priv = tpriv \
  68         }
  69
  70 /*
  71  * Prints the structrue of binary heap into stdout, only for debugging.
  72  */
  73 void GP_TimerQueueDump(GP_Timer *queue);
  74
  75 /*
  76  * Inserts timer into the timer priority queue.
  77  */
  78 void GP_TimerQueueInsert(GP_Timer **queue, uint64_t now, GP_Timer *timer);
  79
  80 /*
  81  * Removes timer from timer queue.
  82  *
  83  * This operation (in contrast with insert and process) runs in O(n) time.
  84  */
  85 void GP_TimerQueueRemove(GP_Timer **queue, GP_Timer *timer);
  86
  87 /*
  88  * Processes queue, all timers with expires <= now are processed.
  89  *
  90  * Returns number of timers processed.
  91  */
  92 int GP_TimerQueueProcess(GP_Timer **queue, uint64_t now);
  93
  94 /*
  95  * Returns size of the queue, i.e. number of timers.
  96  */
  97 static inline unsigned int GP_TimerQueueSize(GP_Timer *queue)
  98 {
  99         return queue ? queue->sons + 1 : 0;
 100 }
 101
 102 #endif /* INPUT_GP_TIMER_H */