lib/monotime.h

   1 /*
   2  * Copyright (c) 2017  David Lamparter, for NetDEF, Inc.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifndef _FRR_MONOTIME_H
  18 #define _FRR_MONOTIME_H
  19
  20 #include <stdint.h>
  21 #include <time.h>
  22 #include <sys/time.h>
  23
  24 #ifndef TIMESPEC_TO_TIMEVAL
  25 /* should be in sys/time.h on BSD & Linux libcs */
  26 #define TIMESPEC_TO_TIMEVAL(tv, ts)                                            \
  27         do {                                                                   \
  28                 (tv)->tv_sec = (ts)->tv_sec;                                   \
  29                 (tv)->tv_usec = (ts)->tv_nsec / 1000;                          \
  30         } while (0)
  31 #endif
  32 #ifndef TIMEVAL_TO_TIMESPEC
  33 /* should be in sys/time.h on BSD & Linux libcs */
  34 #define TIMEVAL_TO_TIMESPEC(tv, ts)                                            \
  35         do {                                                                   \
  36                 (ts)->tv_sec = (tv)->tv_sec;                                   \
  37                 (ts)->tv_nsec = (tv)->tv_usec * 1000;                          \
  38         } while (0)
  39 #endif
  40
  41 static inline time_t monotime(struct timeval *tvo)
  42 {
  43         struct timespec ts;
  44
  45         clock_gettime(CLOCK_MONOTONIC, &ts);
  46         if (tvo) {
  47                 TIMESPEC_TO_TIMEVAL(tvo, &ts);
  48         }
  49         return ts.tv_sec;
  50 }
  51
  52 /* the following two return microseconds, not time_t!
  53  *
  54  * also, they're negative forms of each other, but having both makes the
  55  * code more readable
  56  */
  57 static inline int64_t monotime_since(const struct timeval *ref,
  58                                      struct timeval *out)
  59 {
  60         struct timeval tv;
  61         monotime(&tv);
  62         timersub(&tv, ref, &tv);
  63         if (out)
  64                 *out = tv;
  65         return (int64_t)tv.tv_sec * 1000000LL + tv.tv_usec;
  66 }
  67
  68 static inline int64_t monotime_until(const struct timeval *ref,
  69                                      struct timeval *out)
  70 {
  71         struct timeval tv;
  72         monotime(&tv);
  73         timersub(ref, &tv, &tv);
  74         if (out)
  75                 *out = tv;
  76         return (int64_t)tv.tv_sec * 1000000LL + tv.tv_usec;
  77 }
  78
  79 #endif /* _FRR_MONOTIME_H */