sysdeps/unix/bsd/times.c

   1 /* Copyright (C) 1991, 92, 93, 95, 96 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 <errno.h>
  20 #include <stddef.h>
  21 #include <sys/times.h>
  22 #include <sys/time.h>
  23 #include <sys/resource.h>
  24
  25
  26 /* Time the program started.  */
  27 extern time_t _posix_start_time;
  28
  29 #ifdef  __GNUC__
  30 __inline
  31 #endif
  32 static clock_t
  33 timeval_to_clock_t (tv)
  34      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 __times (buffer)
  46      struct tms *buffer;
  47 {
  48   struct rusage usage;
  49
  50   if (buffer == NULL)
  51     {
  52       __set_errno (EINVAL);
  53       return (clock_t) -1;
  54     }
  55
  56   if (__getrusage (RUSAGE_SELF, &usage) < 0)
  57     return (clock_t) -1;
  58   buffer->tms_utime = (clock_t) timeval_to_clock_t (&usage.ru_utime);
  59   buffer->tms_stime = (clock_t) timeval_to_clock_t (&usage.ru_stime);
  60
  61   if (__getrusage (RUSAGE_CHILDREN, &usage) < 0)
  62     return (clock_t) -1;
  63   buffer->tms_cutime = (clock_t) timeval_to_clock_t (&usage.ru_utime);
  64   buffer->tms_cstime = (clock_t) timeval_to_clock_t (&usage.ru_stime);
  65
  66   return (time ((time_t *) NULL) - _posix_start_time) * CLK_TCK;
  67 }
  68
  69 weak_alias (__times, times)