sysdeps/unix/clock_gettime.c

   1 /* clock_gettime -- Get the current time from a POSIX clockid_t.  Unix version.
   2    Copyright (C) 1999-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <stdint.h>
  21 #include <time.h>
  22 #include <sys/time.h>
  23 #include <libc-internal.h>
  24 #include <ldsodefs.h>
  25
  26
  27 static inline int
  28 realtime_gettime (struct timespec *tp)
  29 {
  30   struct timeval tv;
  31   int retval = __gettimeofday (&tv, NULL);
  32   if (retval == 0)
  33     /* Convert into `timespec'.  */
  34     TIMEVAL_TO_TIMESPEC (&tv, tp);
  35   return retval;
  36 }
  37
  38
  39 /* Get current value of CLOCK and store it in TP.  */
  40 int
  41 __clock_gettime (clockid_t clock_id, struct timespec *tp)
  42 {
  43   int retval = -1;
  44
  45   switch (clock_id)
  46     {
  47     case CLOCK_REALTIME:
  48       {
  49         struct timeval tv;
  50         retval = __gettimeofday (&tv, NULL);
  51         if (retval == 0)
  52           TIMEVAL_TO_TIMESPEC (&tv, tp);
  53       }
  54       break;
  55
  56     default:
  57       __set_errno (EINVAL);
  58       break;
  59     }
  60
  61   return retval;
  62 }
  63 weak_alias (__clock_gettime, clock_gettime)
  64 libc_hidden_def (__clock_gettime)