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 <time.h>
  21 #include <sys/time.h>
  22 #include <shlib-compat.h>
  23
  24 /* Get current value of CLOCK and store it in TP.  */
  25 int
  26 __clock_gettime (clockid_t clock_id, struct timespec *tp)
  27 {
  28   int retval = -1;
  29
  30   switch (clock_id)
  31     {
  32     case CLOCK_REALTIME:
  33       {
  34         struct timeval tv;
  35         retval = __gettimeofday (&tv, NULL);
  36         if (retval == 0)
  37           TIMEVAL_TO_TIMESPEC (&tv, tp);
  38       }
  39       break;
  40
  41     default:
  42       __set_errno (EINVAL);
  43       break;
  44     }
  45
  46   return retval;
  47 }
  48 libc_hidden_def (__clock_gettime)
  49
  50 versioned_symbol (libc, __clock_gettime, clock_gettime, GLIBC_2_17);
  51 /* clock_gettime moved to libc in version 2.17;
  52    old binaries may expect the symbol version it had in librt.  */
  53 #if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
  54 strong_alias (__clock_gettime, __clock_gettime_2);
  55 compat_symbol (libc, __clock_gettime_2, clock_gettime, GLIBC_2_2);
  56 #endif