libgfortran/intrinsics/cpu_time.c

   1 /* Implementation of the CPU_TIME intrinsic.
   2    Copyright (C) 2003 Free Software Foundation, Inc.
   3
   4 This file is part of the GNU Fortran 95 runtime library (libgfortran).
   5
   6 Libgfortran is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU General Public
   8 License as published by the Free Software Foundation; either
   9 version 2 of the License, or (at your option) any later version.
  10
  11 In addition to the permissions in the GNU General Public License, the
  12 Free Software Foundation gives you unlimited permission to link the
  13 compiled version of this file into combinations with other programs,
  14 and to distribute those combinations without any restriction coming
  15 from the use of this file.  (The General Public License restrictions
  16 do apply in other respects; for example, they cover modification of
  17 the file, and distribution when not linked into a combine
  18 executable.)
  19
  20 Libgfortran is distributed in the hope that it will be useful,
  21 but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 GNU General Public License for more details.
  24
  25 You should have received a copy of the GNU General Public
  26 License along with libgfortran; see the file COPYING.  If not,
  27 write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  28 Boston, MA 02110-1301, USA.  */
  29
  30 #include "config.h"
  31 #include <sys/types.h>
  32 #include "libgfortran.h"
  33
  34 #ifdef HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif
  37
  38 /* The CPU_TIME intrinsic to "compare different algorithms on the same
  39    computer or discover which parts are the most expensive", so we
  40    need a way to get the CPU time with the finest resolution possible.
  41    We can only be accurate up to microseconds.
  42
  43    As usual with UNIX systems, unfortunately no single way is
  44    available for all systems.  */
  45
  46 #ifdef TIME_WITH_SYS_TIME
  47 #  include <sys/time.h>
  48 #  include <time.h>
  49 #else
  50 #  if HAVE_SYS_TIME_H
  51 #    include <sys/time.h>
  52 #  else
  53 #    ifdef HAVE_TIME_H
  54 #      include <time.h>
  55 #    endif
  56 #  endif
  57 #endif
  58
  59 /* The most accurate way to get the CPU time is getrusage ().
  60    If we have times(), that's good enough, too.  */
  61 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
  62 #  include <sys/resource.h>
  63 #else
  64 /* For times(), we _must_ know the number of clock ticks per second.  */
  65 #  if defined (HAVE_TIMES) && (defined (HZ) || defined (_SC_CLK_TCK) || defined (CLK_TCK))
  66 #    ifdef HAVE_SYS_PARAM_H
  67 #      include <sys/param.h>
  68 #    endif
  69 #    include <sys/times.h>
  70 #    ifndef HZ
  71 #      if defined _SC_CLK_TCK
  72 #        define HZ  sysconf(_SC_CLK_TCK)
  73 #      else
  74 #        define HZ  CLK_TCK
  75 #      endif
  76 #    endif
  77 #  endif  /* HAVE_TIMES etc.  */
  78 #endif  /* HAVE_GETRUSAGE && HAVE_SYS_RESOURCE_H  */
  79
  80 #if defined (__GNUC__) && (__GNUC__ >= 3)
  81 #  define ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__))
  82 #else
  83 #  define ATTRIBUTE_ALWAYS_INLINE
  84 #endif
  85
  86 static inline void __cpu_time_1 (long *, long *) ATTRIBUTE_ALWAYS_INLINE;
  87
  88 /* Helper function for the actual implementation of the CPU_TIME
  89    intrnsic.  Returns a CPU time in microseconds or -1 if no CPU time
  90    could be computed.  */
  91
  92 #ifdef __MINGW32__
  93
  94 #define WIN32_LEAN_AND_MEAN
  95 #include <windows.h>
  96
  97 static void
  98 __cpu_time_1 (long *sec, long *usec)
  99 {
 100   union {
 101     FILETIME ft;
 102     unsigned long long ulltime;
 103   } kernel_time,  user_time;
 104
 105   FILETIME unused1, unused2;
 106   unsigned long long total_time;
 107
 108   /* No support for Win9x.  The high order bit of the DWORD
 109      returned by GetVersion is 0 for NT and higher. */
 110   if (GetVersion () >= 0x80000000)
 111     {
 112       *sec = -1;
 113       *usec = 0;
 114       return;
 115     }
 116
 117   /* The FILETIME structs filled in by GetProcessTimes represent
 118      time in 100 nanosecond units. */
 119   GetProcessTimes (GetCurrentProcess (), &unused1, &unused2,
 120                    &kernel_time.ft, &user_time.ft);
 121
 122   total_time = (kernel_time.ulltime + user_time.ulltime)/10;
 123   *sec = total_time / 1000000;
 124   *usec = total_time % 1000000;
 125 }
 126
 127 #else
 128
 129 static inline void
 130 __cpu_time_1 (long *sec, long *usec)
 131 {
 132 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
 133   struct rusage usage;
 134   getrusage (0, &usage);
 135   *sec = usage.ru_utime.tv_sec + usage.ru_stime.tv_sec;
 136   *usec = usage.ru_utime.tv_usec + usage.ru_stime.tv_usec;
 137 #else /* ! HAVE_GETRUSAGE || ! HAVE_SYS_RESOURCE_H  */
 138 #ifdef HAVE_TIMES
 139   struct tms buf;
 140   times (&buf);
 141   *sec = 0;
 142   *usec = (buf.tms_utime + buf.tms_stime) * (1000000 / HZ);
 143 #else /* ! HAVE_TIMES */
 144   /* We have nothing to go on.  Return -1.  */
 145   *sec = -1;
 146   *usec = 0;
 147 #endif  /* HAVE_TIMES */
 148 #endif  /* HAVE_GETRUSAGE */
 149 }
 150
 151 #endif
 152
 153 extern void cpu_time_4 (GFC_REAL_4 *);
 154 iexport_proto(cpu_time_4);
 155
 156 void cpu_time_4 (GFC_REAL_4 *time)
 157 {
 158   long sec, usec;
 159   __cpu_time_1 (&sec, &usec);
 160   *time = sec + usec * (GFC_REAL_4)1.e-6;
 161 }
 162 iexport(cpu_time_4);
 163
 164 extern void cpu_time_8 (GFC_REAL_8 *);
 165 export_proto(cpu_time_8);
 166
 167 void cpu_time_8 (GFC_REAL_8 *time)
 168 {
 169   long sec, usec;
 170   __cpu_time_1 (&sec, &usec);
 171   *time = sec + usec * (GFC_REAL_8)1.e-6;
 172 }
 173
 174 extern void second_sub (GFC_REAL_4 *);
 175 export_proto(second_sub);
 176
 177 void
 178 second_sub (GFC_REAL_4 *s)
 179 {
 180   cpu_time_4 (s);
 181 }
 182
 183 extern GFC_REAL_4 second (void);
 184 export_proto(second);
 185
 186 GFC_REAL_4
 187 second (void)
 188 {
 189   GFC_REAL_4 s;
 190   cpu_time_4 (&s);
 191   return s;
 192 }