libc/sysdeps/linux/common/clock_getres.c

   1 /*
   2  * clock_getres() for uClibc
   3  *
   4  * Copyright (C) 2005 by Peter Kjellerstedt <pkj@axis.com>
   5  * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
   6  *
   7  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   8  */
   9
  10 #include <sys/syscall.h>
  11 #include <time.h>
  12 #include <unistd.h>
  13
  14 #ifdef __NR_clock_getres
  15 _syscall2(int, clock_getres, clockid_t, clock_id, struct timespec*, res)
  16 #else
  17 /* libc_hidden_proto(sysconf) */
  18
  19 int clock_getres(clockid_t clock_id, struct timespec* res)
  20 {
  21         int retval = -1;
  22
  23         switch (clock_id) {
  24                 case CLOCK_REALTIME:
  25                         if (res) {
  26                                 long clk_tck;
  27
  28                                 if ((clk_tck = sysconf(_SC_CLK_TCK)) < 0)
  29                                         clk_tck = 100;
  30                                 res->tv_sec = 0;
  31                                 res->tv_nsec = 1000000000 / clk_tck;
  32                         }
  33                         retval = 0;
  34                         break;
  35
  36                 default:
  37                         errno = EINVAL;
  38                         break;
  39         }
  40
  41         return retval;
  42 }
  43 #endif
  44 libc_hidden_def(clock_getres)