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) do {        \
  27         (tv)->tv_sec = (ts)->tv_sec;            \
  28         (tv)->tv_usec = (ts)->tv_nsec / 1000;   \
  29         } while (0)
  30 #endif
  31 #ifndef TIMEVAL_TO_TIMESPEC
  32 /* should be in sys/time.h on BSD & Linux libcs */
  33 #define TIMEVAL_TO_TIMESPEC(tv, ts) do {        \
  34         (ts)->tv_sec = (tv)->tv_sec;            \
  35         (ts)->tv_nsec = (tv)->tv_usec * 1000;   \
  36         } while (0)
  37 #endif
  38
  39 static inline time_t monotime(struct timeval *tvo)
  40 {
  41         struct timespec ts;
  42
  43         clock_gettime(CLOCK_MONOTONIC, &ts);
  44         if (tvo) {
  45                 TIMESPEC_TO_TIMEVAL(tvo, &ts);
  46         }
  47         return ts.tv_sec;
  48 }
  49
  50 /* the following two return microseconds, not time_t!
  51  *
  52  * also, they're negative forms of each other, but having both makes the
  53  * code more readable
  54  */
  55 static inline int64_t monotime_since(const struct timeval *ref,
  56                                      struct timeval *out)
  57 {
  58         struct timeval tv;
  59         monotime(&tv);
  60         timersub(&tv, ref, &tv);
  61         if (out)
  62                 *out = tv;
  63         return (int64_t)tv.tv_sec * 1000000LL + tv.tv_usec;
  64 }
  65
  66 static inline int64_t monotime_until(const struct timeval *ref,
  67                                      struct timeval *out)
  68 {
  69         struct timeval tv;
  70         monotime(&tv);
  71         timersub(ref, &tv, &tv);
  72         if (out)
  73                 *out = tv;
  74         return (int64_t)tv.tv_sec * 1000000LL + tv.tv_usec;
  75 }
  76
  77 #endif /* _FRR_MONOTIME_H */