sysdeps/unix/bsd/clock.c

   1 /* Copyright (C) 1991 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <sys/resource.h>
  21 #include <time.h>
  22 #include <sys/time.h>
  23
  24 #ifdef  __GNUC__
  25 __inline
  26 #endif
  27 static clock_t
  28 DEFUN(timeval_to_clock_t, (tv), CONST struct timeval *tv)
  29 {
  30   return (clock_t) ((tv->tv_sec * CLK_TCK) +
  31                     (tv->tv_usec * CLK_TCK / 1000000));
  32 }
  33
  34 /* Return the time used by the program so far (user time + system time).  */
  35 clock_t
  36 DEFUN_VOID(clock)
  37 {
  38   struct rusage usage;
  39
  40   if (__getrusage(RUSAGE_SELF, &usage) < 0)
  41     return (clock_t) -1;
  42
  43   return (timeval_to_clock_t(&usage.ru_stime) +
  44           timeval_to_clock_t(&usage.ru_utime));
  45 }