sysdeps/unix/bsd/clock.c

   1 /* Copyright (C) 1991, 1997, 1998, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <sys/resource.h>
  20 #include <sys/time.h>
  21 #include <time.h>
  22
  23 #ifdef  __GNUC__
  24 __inline
  25 #endif
  26 static clock_t
  27 timeval_to_clock_t (const struct timeval *tv)
  28 {
  29   return (clock_t) ((tv->tv_sec * CLOCKS_PER_SEC) +
  30                     (tv->tv_usec * CLOCKS_PER_SEC / 1000000));
  31 }
  32
  33 /* Return the time used by the program so far (user time + system time).  */
  34 clock_t
  35 clock (void)
  36 {
  37   struct rusage usage;
  38
  39   if (__getrusage (RUSAGE_SELF, &usage) < 0)
  40     return (clock_t) -1;
  41
  42   return (timeval_to_clock_t (&usage.ru_stime) +
  43           timeval_to_clock_t (&usage.ru_utime));
  44 }