tests/framework/tst_timespec.c

   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) 2009-2012 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23 #include "tst_timespec.h"
  24
  25 #define NSEC_IN_SEC 1000000000
  26
  27 void timespec_diff(int *sec, int *nsec,
  28                    const struct timespec *start,
  29                    const struct timespec *stop)
  30 {
  31         if (stop->tv_nsec < start->tv_nsec) {
  32                 *sec  = stop->tv_sec - start->tv_sec - 1;
  33                 *nsec = stop->tv_nsec + 1000000000 - start->tv_nsec;
  34         } else {
  35                 *sec  = stop->tv_sec  - start->tv_sec;
  36                 *nsec = stop->tv_nsec - start->tv_nsec;
  37         }
  38 }
  39
  40 double timespec_to_double(const struct timespec *t)
  41 {
  42         double res;
  43
  44         res = t->tv_sec;
  45         res *= NSEC_IN_SEC;
  46         res += t->tv_nsec;
  47
  48         return res;
  49 }
  50
  51 void double_to_timespec(const double time, struct timespec *res)
  52 {
  53         res->tv_sec = time / NSEC_IN_SEC;
  54         res->tv_nsec = time - res->tv_sec * NSEC_IN_SEC;
  55 }
  56
  57 void timespec_sub(const struct timespec *a, const struct timespec *b,
  58                   struct timespec *res)
  59 {
  60         res->tv_sec = a->tv_sec - b->tv_sec;
  61         time_t nsec = a->tv_nsec;
  62
  63         if (b->tv_nsec > a->tv_nsec) {
  64                 res->tv_sec--;
  65                 nsec += NSEC_IN_SEC;
  66         }
  67
  68         res->tv_nsec = nsec - b->tv_nsec;
  69 }
  70
  71 void timespec_add(const struct timespec *a, struct timespec *res)
  72 {
  73         res->tv_sec  += a->tv_sec;
  74         res->tv_nsec += a->tv_nsec;
  75
  76         if (res->tv_nsec >= NSEC_IN_SEC) {
  77                 res->tv_sec += res->tv_nsec / NSEC_IN_SEC;
  78                 res->tv_nsec %= NSEC_IN_SEC;
  79         }
  80 }
  81
  82 void timespec_div(struct timespec *res, unsigned int div)
  83 {
  84         long sec = res->tv_sec;
  85
  86         res->tv_sec /= div;
  87         sec %= div;
  88
  89         res->tv_nsec = (sec * NSEC_IN_SEC + res->tv_nsec)/div;
  90 }