timer.h

   1 #ifndef TIMER_H
   2 #define TIMER_H
   3
   4 #include <sys/time.h>
   5 #include <sys/resource.h>
   6
   7 #if NEED_TIMERCLEAR
   8 inline
   9 void timerclear(struct timeval& a)
  10 {
  11     tv.sec = tv.usec = 0;
  12 }
  13 #endif
  14
  15 inline
  16 struct timeval operator+(const struct timeval& a, const struct timeval& b)
  17 {
  18     struct timeval result;
  19     result.tv_sec = a.tv_sec + b.tv_sec;
  20     result.tv_usec = a.tv_usec + b.tv_usec;
  21     if (result.tv_usec >= 1000000) {
  22         ++result.tv_sec;
  23         result.tv_usec -= 1000000;
  24     }
  25     return result;
  26 }
  27
  28 inline
  29 struct timeval operator-(const struct timeval& a, const struct timeval& b)
  30 {
  31     struct timeval result;
  32     result.tv_sec = a.tv_sec - b.tv_sec;
  33     result.tv_usec = a.tv_usec - b.tv_usec;
  34     if (result.tv_usec < 0) {
  35         -- result.tv_sec;
  36         result.tv_usec += 1000000;
  37     }
  38     return result;
  39 }
  40
  41 double timertod(const struct timeval& a)
  42 {
  43     return a.tv_sec + a.tv_usec / 1e6;
  44 }
  45
  46 class timestamp {
  47 private:
  48     struct rusage before;
  49     struct rusage after;
  50     struct timeval difference;
  51
  52 public:
  53     timestamp()
  54     {
  55         reset();
  56     }
  57
  58     void reset()
  59     {
  60         timerclear(&before.ru_utime);
  61         timerclear(&before.ru_stime);
  62         timerclear(&after.ru_utime);
  63         timerclear(&after.ru_stime);
  64         timerclear(&difference);
  65     }
  66
  67     void start()
  68     {
  69         getrusage(RUSAGE_SELF, &before);
  70     }
  71
  72     void stop()
  73     {
  74         getrusage(RUSAGE_SELF, &after);
  75         difference = difference + ((after.ru_utime + after.ru_stime) -
  76                                    (before.ru_utime + before.ru_stime));
  77     }
  78
  79     struct timeval tv_duration() const
  80     {
  81         return difference;
  82     }
  83
  84     double duration() const
  85     {
  86         return timertod(difference);
  87     }
  88 };
  89
  90 #endif // !TIMER_H
  91
  92 // Local variables:
  93 // mode: c++
  94 // End: