lib/times.c

   1 /* Get process times
   2
   3    Copyright (C) 2008-2025 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Simon Josefsson <simon@josefsson.org>, 2008.  */
  19
  20 #include <config.h>
  21
  22 /* Get times prototype. */
  23 #include <sys/times.h>
  24
  25 /* Get round. */
  26 #include <math.h>
  27
  28 /* Get GetProcessTimes etc. */
  29 #include <windows.h>
  30
  31 static clock_t
  32 filetime2clock (FILETIME time)
  33 {
  34   float f;
  35
  36   /* We have a 64-bit value, in the form of two DWORDS aka unsigned
  37      int, counting the number of 100-nanosecond intervals.  We need to
  38      convert these to clock ticks.  Older POSIX uses CLK_TCK to
  39      indicate the number of clock ticks per second while modern POSIX
  40      uses sysconf(_SC_CLK_TCK).  Mingw32 does not appear to have
  41      sysconf(_SC_CLK_TCK), but appears to have CLK_TCK = 1000 so we
  42      use it.  Note that CLOCKS_PER_SEC constant does not apply here,
  43      it is for use with the clock function.  */
  44
  45   f = (unsigned long long) time.dwHighDateTime << 32;
  46   f += time.dwLowDateTime;
  47   f = f * CLK_TCK / 10000000;
  48   return (clock_t) round (f);
  49 }
  50
  51 clock_t
  52 times (struct tms * buffer)
  53 {
  54   FILETIME creation_time, exit_time, kernel_time, user_time;
  55
  56   if (GetProcessTimes (GetCurrentProcess (), &creation_time, &exit_time,
  57                        &kernel_time, &user_time) == 0)
  58     return (clock_t) -1;
  59
  60   buffer->tms_utime = filetime2clock (user_time);
  61   buffer->tms_stime = filetime2clock (kernel_time);
  62   buffer->tms_cutime = 0;
  63   buffer->tms_cstime = 0;
  64
  65   return clock ();
  66 }