mdw@git.distorted.org.uk Git - disorder/blob - lib/timeval.h

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2007-2009, 2013 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/timeval.h
  19  * @brief Arithmetic on timeval structures
  20  */
  21 #ifndef TIMEVAL_H
  22 #define TIMEVAL_H
  23
  24 #include <time.h>
  25 #include <sys/time.h>
  26 #include <math.h>
  27
  28 static inline struct timeval tvsub(const struct timeval a,
  29                                    const struct timeval b) {
  30   struct timeval r;
  31
  32   r.tv_sec = a.tv_sec - b.tv_sec;
  33   r.tv_usec = a.tv_usec - b.tv_usec;
  34   if(r.tv_usec < 0) {
  35     r.tv_usec += 1000000;
  36     r.tv_sec--;
  37   }
  38   if(r.tv_usec > 999999) {
  39     r.tv_usec -= 1000000;
  40     r.tv_sec++;
  41   }
  42   return r;
  43 }
  44
  45 static inline struct timeval tvadd(const struct timeval a,
  46                                    const struct timeval b) {
  47   struct timeval r;
  48
  49   r.tv_sec = a.tv_sec + b.tv_sec;
  50   r.tv_usec = a.tv_usec + b.tv_usec;
  51   if(r.tv_usec < 0) {
  52     r.tv_usec += 1000000;
  53     r.tv_sec--;
  54   }
  55   if(r.tv_usec > 999999) {
  56     r.tv_usec -= 1000000;
  57     r.tv_sec++;
  58   }
  59   return r;
  60 }
  61
  62 static inline double tvdouble(const struct timeval a) {
  63   return a.tv_sec + a.tv_usec / 1000000.0;
  64 }
  65
  66 static inline int64_t tvsub_us(const struct timeval a,
  67                                const struct timeval b) {
  68   return (((uint64_t)a.tv_sec * 1000000 + a.tv_usec)
  69           - ((uint64_t)b.tv_sec * 1000000 + b.tv_usec));
  70 }
  71
  72 /** @brief Great-than comparison for timevals */
  73 static inline int tvgt(const struct timeval *a, const struct timeval *b) {
  74   if(a->tv_sec > b->tv_sec)
  75     return 1;
  76   if(a->tv_sec == b->tv_sec
  77      && a->tv_usec > b->tv_usec)
  78     return 1;
  79   return 0;
  80 }
  81
  82 /** @brief Less-than
  83     comparison for timevals */
  84 static inline int tvlt(const struct timeval *a, const struct timeval *b) {
  85   if(a->tv_sec < b->tv_sec)
  86     return 1;
  87   if(a->tv_sec == b->tv_sec
  88      && a->tv_usec < b->tv_usec)
  89     return 1;
  90   return 0;
  91 }
  92
  93 /** @brief Greater-than-or-equal comparison for timevals */
  94 static inline int tvge(const struct timeval *a, const struct timeval *b) {
  95   return !tvlt(a, b);
  96 }
  97
  98 /** @brief Less-than-or-equal comparison for timevals */
  99 static inline int tvle(const struct timeval *a, const struct timeval *b) {
 100   return !tvgt(a, b);
 101 }
 102
 103 /** @brief Return the sum of two timespecs */
 104 static inline struct timespec tsadd(const struct timespec a,
 105                                     const struct timespec b) {
 106   struct timespec r;
 107
 108   r.tv_sec = a.tv_sec + b.tv_sec;
 109   r.tv_nsec = a.tv_nsec + b.tv_nsec;
 110   if(r.tv_nsec < 0) {
 111     r.tv_nsec += 1000000;
 112     r.tv_sec--;
 113   }
 114   if(r.tv_nsec > 999999) {
 115     r.tv_nsec -= 1000000;
 116     r.tv_sec++;
 117   }
 118   return r;
 119 }
 120
 121 /** @brief Subtract one timespec from another */
 122 static inline struct timespec tssub(const struct timespec a,
 123                                     const struct timespec b) {
 124   struct timespec r;
 125
 126   r.tv_sec = a.tv_sec - b.tv_sec;
 127   r.tv_nsec = a.tv_nsec - b.tv_nsec;
 128   if(r.tv_nsec < 0) {
 129     r.tv_nsec += 1000000;
 130     r.tv_sec--;
 131   }
 132   if(r.tv_nsec > 999999) {
 133     r.tv_nsec -= 1000000;
 134     r.tv_sec++;
 135   }
 136   return r;
 137 }
 138
 139 /** @brief Convert a timespec to a double */
 140 static inline double ts_to_double(const struct timespec ts) {
 141   return ts.tv_sec + ts.tv_nsec / 1000000000.0;
 142 }
 143
 144 /** @brief Convert a double to a timespec */
 145 static inline struct timespec double_to_ts(double n) {
 146   double i, f;
 147   struct timespec r;
 148   f = modf(n, &i);
 149   r.tv_sec = i;
 150   r.tv_nsec = 1000000000 * f;
 151   return r;
 152 }
 153
 154 #endif /* TIMEVAL_H */
 155
 156 /*
 157 Local Variables:
 158 c-basic-offset:2
 159 comment-column:40
 160 fill-column:79
 161 indent-tabs-mode:nil
 162 End:
 163 */