libgfortran/intrinsics/system_clock.c

   1 /* Implementation of the SYSTEM_CLOCK intrinsic.
   2    Copyright (C) 2004, 2005, 2007, 2009, 2010, 2011 Free Software
   3    Foundation, Inc.
   4
   5 This file is part of the GNU Fortran runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU General Public
   9 License as published by the Free Software Foundation; either
  10 version 3 of the License, or (at your option) any later version.
  11
  12 Libgfortran is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27
  28 #include <limits.h>
  29
  30 #include "time_1.h"
  31
  32 extern void system_clock_4 (GFC_INTEGER_4 *, GFC_INTEGER_4 *, GFC_INTEGER_4 *);
  33 export_proto(system_clock_4);
  34
  35 extern void system_clock_8 (GFC_INTEGER_8 *, GFC_INTEGER_8 *, GFC_INTEGER_8 *);
  36 export_proto(system_clock_8);
  37
  38
  39 /* prefix(system_clock_4) is the INTEGER(4) version of the SYSTEM_CLOCK
  40    intrinsic subroutine.  It returns the number of clock ticks for the current
  41    system time, the number of ticks per second, and the maximum possible value
  42    for COUNT.  On the first call to SYSTEM_CLOCK, COUNT is set to zero. */
  43
  44 void
  45 system_clock_4(GFC_INTEGER_4 *count, GFC_INTEGER_4 *count_rate,
  46                GFC_INTEGER_4 *count_max)
  47 {
  48 #undef TCK
  49 #define TCK 1000
  50   GFC_INTEGER_4 cnt;
  51   GFC_INTEGER_4 mx;
  52
  53   time_t secs;
  54   long nanosecs;
  55
  56   if (sizeof (secs) < sizeof (GFC_INTEGER_4))
  57     internal_error (NULL, "secs too small");
  58
  59   if (gf_gettime (GF_CLOCK_MONOTONIC, &secs, &nanosecs) == 0)
  60     {
  61       GFC_UINTEGER_4 ucnt = (GFC_UINTEGER_4) secs * TCK;
  62       ucnt += (nanosecs + 500000000 / TCK) / (1000000000 / TCK);
  63       if (ucnt > GFC_INTEGER_4_HUGE)
  64         cnt = ucnt - GFC_INTEGER_4_HUGE - 1;
  65       else
  66         cnt = ucnt;
  67       mx = GFC_INTEGER_4_HUGE;
  68     }
  69   else
  70     {
  71       if (count != NULL)
  72         *count = - GFC_INTEGER_4_HUGE;
  73       if (count_rate != NULL)
  74         *count_rate = 0;
  75       if (count_max != NULL)
  76         *count_max = 0;
  77       return;
  78     }
  79
  80   if (count != NULL)
  81     *count = cnt;
  82   if (count_rate != NULL)
  83     *count_rate = TCK;
  84   if (count_max != NULL)
  85     *count_max = mx;
  86 }
  87
  88
  89 /* INTEGER(8) version of the above routine.  */
  90
  91 void
  92 system_clock_8 (GFC_INTEGER_8 *count, GFC_INTEGER_8 *count_rate,
  93                 GFC_INTEGER_8 *count_max)
  94 {
  95 #undef TCK
  96 #define TCK 1000000000
  97   GFC_INTEGER_8 cnt;
  98   GFC_INTEGER_8 mx;
  99
 100   time_t secs;
 101   long nanosecs;
 102
 103   if (sizeof (secs) < sizeof (GFC_INTEGER_4))
 104     internal_error (NULL, "secs too small");
 105
 106   if (gf_gettime (GF_CLOCK_MONOTONIC, &secs, &nanosecs) == 0)
 107     {
 108       GFC_UINTEGER_8 ucnt = (GFC_UINTEGER_8) secs * TCK;
 109       ucnt += (nanosecs + 500000000 / TCK) / (1000000000 / TCK);
 110       if (ucnt > GFC_INTEGER_8_HUGE)
 111         cnt = ucnt - GFC_INTEGER_8_HUGE - 1;
 112       else
 113         cnt = ucnt;
 114       mx = GFC_INTEGER_8_HUGE;
 115     }
 116   else
 117     {
 118       if (count != NULL)
 119         *count = - GFC_INTEGER_8_HUGE;
 120       if (count_rate != NULL)
 121         *count_rate = 0;
 122       if (count_max != NULL)
 123         *count_max = 0;
 124
 125       return;
 126     }
 127
 128   if (count != NULL)
 129     *count = cnt;
 130   if (count_rate != NULL)
 131     *count_rate = TCK;
 132   if (count_max != NULL)
 133     *count_max = mx;
 134 }