sysdeps/unix/bsd/times.c

   1 /* Copyright (C) 1991, 1992, 1993, 1995 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 <errno.h>
  21 #include <stddef.h>
  22 #include <sys/times.h>
  23 #include <sys/time.h>
  24 #include <sys/resource.h>
  25
  26
  27 /* Time the program started.  */
  28 extern time_t _posix_start_time;
  29
  30 #ifdef  __GNUC__
  31 __inline
  32 #endif
  33 static clock_t
  34 DEFUN(timeval_to_clock_t, (tv), CONST struct timeval *tv)
  35 {
  36   return (clock_t) ((tv->tv_sec * CLK_TCK) +
  37                     (tv->tv_usec * CLK_TCK / 1000000L));
  38 }
  39
  40 /* Store the CPU time used by this process and all its
  41    dead children (and their dead children) in BUFFER.
  42    Return the elapsed real time, or (clock_t) -1 for errors.
  43    All times are in CLK_TCKths of a second.  */
  44 clock_t
  45 DEFUN(__times, (buffer), struct tms *buffer)
  46 {
  47   struct rusage usage;
  48
  49   if (buffer == NULL)
  50     {
  51       errno = EINVAL;
  52       return (clock_t) -1;
  53     }
  54
  55   if (__getrusage(RUSAGE_SELF, &usage) < 0)
  56     return (clock_t) -1;
  57   buffer->tms_utime = (clock_t) timeval_to_clock_t(&usage.ru_utime);
  58   buffer->tms_stime = (clock_t) timeval_to_clock_t(&usage.ru_stime);
  59
  60   if (__getrusage(RUSAGE_CHILDREN, &usage) < 0)
  61     return (clock_t) -1;
  62   buffer->tms_cutime = (clock_t) timeval_to_clock_t(&usage.ru_utime);
  63   buffer->tms_cstime = (clock_t) timeval_to_clock_t(&usage.ru_stime);
  64
  65   return (time((time_t *) NULL) - _posix_start_time) * CLK_TCK;
  66 }
  67
  68 weak_alias (__times, times)