sysdeps/unix/sysv/linux/clock_getres.c

   1 /* clock_getres -- Get the resolution of a POSIX clockid_t.  Linux version.
   2    Copyright (C) 2003-2019 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20 #include <errno.h>
  21 #include <time.h>
  22 #include "kernel-posix-cpu-timers.h"
  23
  24 #ifdef HAVE_CLOCK_GETRES_VSYSCALL
  25 # define HAVE_VSYSCALL
  26 #endif
  27 #include <sysdep-vdso.h>
  28
  29 #include <shlib-compat.h>
  30
  31 /* Get resolution of clock.  */
  32 int
  33 __clock_getres (clockid_t clock_id, struct timespec *res)
  34 {
  35   return INLINE_VSYSCALL (clock_getres, 2, clock_id, res);
  36 }
  37
  38 versioned_symbol (libc, __clock_getres, clock_getres, GLIBC_2_17);
  39 /* clock_getres moved to libc in version 2.17;
  40    old binaries may expect the symbol version it had in librt.  */
  41 #if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
  42 strong_alias (__clock_getres, __clock_getres_2);
  43 compat_symbol (libc, __clock_getres_2, clock_getres, GLIBC_2_2);
  44 #endif