ltt/branches/poly/ltt/time.h

   1 /* This file is part of the Linux Trace Toolkit trace reading library
   2  * Copyright (C) 2003-2004 Michel Dagenais
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License Version 2.1 as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 02111-1307, USA.
  17  */
  18
  19 #ifndef LTT_TIME_H
  20 #define LTT_TIME_H
  21
  22 #include <glib.h>
  23
  24
  25 typedef struct _LttTime {
  26   unsigned long tv_sec;
  27   unsigned long tv_nsec;
  28 } LttTime;
  29
  30
  31 #define NANOSECONDS_PER_SECOND 1000000000
  32
  33 static const LttTime ltt_time_zero = { 0, 0 };
  34
  35 static const LttTime ltt_time_one = { 0, 1 };
  36
  37 static const LttTime ltt_time_infinite = { G_MAXUINT, NANOSECONDS_PER_SECOND };
  38
  39 static inline LttTime ltt_time_sub(LttTime t1, LttTime t2)
  40 {
  41   LttTime res;
  42   res.tv_sec  = t1.tv_sec  - t2.tv_sec;
  43   if(t1.tv_nsec < t2.tv_nsec) {
  44     res.tv_sec--;
  45     res.tv_nsec = NANOSECONDS_PER_SECOND + t1.tv_nsec - t2.tv_nsec;
  46   }
  47   else {
  48     res.tv_nsec = t1.tv_nsec - t2.tv_nsec;
  49   }
  50   return res;
  51 }
  52
  53
  54 static inline LttTime ltt_time_add(LttTime t1, LttTime t2)
  55 {
  56   LttTime res;
  57   res.tv_sec  = t1.tv_sec  + t2.tv_sec;
  58   res.tv_nsec = t1.tv_nsec + t2.tv_nsec;
  59   if(res.tv_nsec >= NANOSECONDS_PER_SECOND) {
  60     res.tv_sec++;
  61     res.tv_nsec -= NANOSECONDS_PER_SECOND;
  62   }
  63   return res;
  64 }
  65
  66
  67 static inline int ltt_time_compare(LttTime t1, LttTime t2)
  68 {
  69   if(t1.tv_sec > t2.tv_sec) return 1;
  70   if(t1.tv_sec < t2.tv_sec) return -1;
  71   if(t1.tv_nsec > t2.tv_nsec) return 1;
  72   if(t1.tv_nsec < t2.tv_nsec) return -1;
  73   return 0;
  74 }
  75
  76 #define LTT_TIME_MIN(a,b) ((ltt_time_compare((a),(b)) < 0) ? (a) : (b))
  77 #define LTT_TIME_MAX(a,b) ((ltt_time_compare((a),(b)) > 0) ? (a) : (b))
  78
  79 #define MAX_TV_SEC_TO_DOUBLE 0x7FFFFF
  80 static inline double ltt_time_to_double(LttTime t1)
  81 {
  82   /* We lose precision if tv_sec is > than (2^23)-1
  83    *
  84    * Max values that fits in a double (53 bits precision on normalised
  85    * mantissa):
  86    * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
  87    *
  88    * So we have 53-30 = 23 bits left for tv_sec.
  89    * */
  90   g_assert(t1.tv_sec <= MAX_TV_SEC_TO_DOUBLE);
  91   if(t1.tv_sec > MAX_TV_SEC_TO_DOUBLE)
  92     g_warning("Precision loss in conversion LttTime to double");
  93   return (double)t1.tv_sec + (double)t1.tv_nsec / NANOSECONDS_PER_SECOND;
  94 }
  95
  96
  97 static inline LttTime ltt_time_from_double(double t1)
  98 {
  99   /* We lose precision if tv_sec is > than (2^23)-1
 100    *
 101    * Max values that fits in a double (53 bits precision on normalised
 102    * mantissa):
 103    * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
 104    *
 105    * So we have 53-30 = 23 bits left for tv_sec.
 106    * */
 107   g_assert(t1 <= MAX_TV_SEC_TO_DOUBLE);
 108   if(t1 > MAX_TV_SEC_TO_DOUBLE)
 109     g_warning("Conversion from non precise double to LttTime");
 110   LttTime res;
 111   res.tv_sec = t1;
 112   res.tv_nsec = (t1 - res.tv_sec) * NANOSECONDS_PER_SECOND;
 113   return res;
 114 }
 115
 116 /* Use ltt_time_to_double and ltt_time_from_double to check for lack
 117  * of precision.
 118  */
 119 static inline LttTime ltt_time_mul(LttTime t1, double d)
 120 {
 121   LttTime res;
 122
 123   double time_double = ltt_time_to_double(t1);
 124
 125   time_double = time_double * d;
 126
 127   res = ltt_time_from_double(time_double);
 128
 129   return res;
 130
 131 #if 0
 132   /* What is that ? (Mathieu) */
 133   if(f == 0.0){
 134     res.tv_sec = 0;
 135     res.tv_nsec = 0;
 136   }else{
 137   double d;
 138     d = 1.0/f;
 139     sec = t1.tv_sec / (double)d;
 140     res.tv_sec = sec;
 141     res.tv_nsec = t1.tv_nsec / (double)d + (sec - res.tv_sec) *
 142                   NANOSECONDS_PER_SECOND;
 143     res.tv_sec += res.tv_nsec / NANOSECONDS_PER_SECOND;
 144     res.tv_nsec %= NANOSECONDS_PER_SECOND;
 145   }
 146   return res;
 147 #endif //0
 148 }
 149
 150
 151 /* Use ltt_time_to_double and ltt_time_from_double to check for lack
 152  * of precision.
 153  */
 154 static inline LttTime ltt_time_div(LttTime t1, double d)
 155 {
 156   LttTime res;
 157
 158   double time_double = ltt_time_to_double(t1);
 159
 160   time_double = time_double / d;
 161
 162   res = ltt_time_from_double(time_double);
 163
 164   return res;
 165
 166
 167 #if 0
 168   double sec;
 169   LttTime res;
 170
 171   sec = t1.tv_sec / (double)f;
 172   res.tv_sec = sec;
 173   res.tv_nsec = t1.tv_nsec / (double)f + (sec - res.tv_sec) *
 174       NANOSECONDS_PER_SECOND;
 175   res.tv_sec += res.tv_nsec / NANOSECONDS_PER_SECOND;
 176   res.tv_nsec %= NANOSECONDS_PER_SECOND;
 177   return res;
 178 #endif //0
 179 }
 180
 181 static inline guint64 ltt_time_to_uint64(LttTime t1)
 182 {
 183   return (guint64)t1.tv_sec*NANOSECONDS_PER_SECOND
 184             + (guint64)t1.tv_nsec;
 185 }
 186
 187
 188 #define MAX_TV_SEC_TO_UINT64 0x3FFFFFFFFFFFFFFFULL
 189 static inline LttTime ltt_time_from_uint64(guint64 t1)
 190 {
 191   /* We lose precision if tv_sec is > than (2^62)-1
 192    * */
 193   g_assert(t1 <= MAX_TV_SEC_TO_UINT64);
 194   if(t1 > MAX_TV_SEC_TO_UINT64)
 195     g_warning("Conversion from non precise uint64 to LttTime");
 196   LttTime res;
 197   res.tv_sec = t1/NANOSECONDS_PER_SECOND;
 198   res.tv_nsec = (t1 - res.tv_sec*NANOSECONDS_PER_SECOND);
 199   return res;
 200 }
 201
 202 #endif // LTT_TIME_H