timer.h

   1 #ifndef TIMER_H
   2 #define TIMER_H
   3
   4 #include <sys/time.h>
   5 #include <sys/resource.h>
   6
   7 #ifdef _BSD_SOURCE
   8 #  define HAVE_TIMERADD
   9 #  define HAVE_TIMERSUB
  10 #  define HAVE_TIMERCLEAR
  11 #else
  12 #  warning _BSD_SOURCE not defined
  13 #  undef HAVE_TIMERADD
  14 #  undef HAVE_TIMERSUB
  15 #  undef HAVE_TIMERCLEAR
  16 #endif
  17
  18 inline
  19 struct timeval operator+(const struct timeval& a, const struct timeval& b)
  20 {
  21     struct timeval result;
  22 #ifdef HAVE_TIMERADD
  23     timeradd(&a, &b, &result);
  24 #else
  25     result.tv_sec = a.tv_sec + b.tv_sec;
  26     result.tv_usec = a.tv_usec + b.tv_usec;
  27     if (result.tv_usec >= 1000000) {
  28         ++result.tv_sec;
  29         result.tv_usec -= 1000000;
  30     }
  31 #endif
  32     return result;
  33 }
  34
  35 inline
  36 struct timeval operator-(const struct timeval& a, const struct timeval& b)
  37 {
  38     struct timeval result;
  39 #ifdef HAVE_TIMERSUB
  40     timersub(&a, &b, &result);
  41 #else
  42     result.tv_sec = a.tv_sec - b.tv_sec;
  43     result.tv_usec = a.tv_usec - b.tv_usec;
  44     if (result.tv_usec < 0) {
  45         --result.tv_sec;
  46         result.tv_usec += 1000000;
  47     }
  48 #endif
  49     return result;
  50 }
  51
  52 class timestamp {
  53 public:
  54     timestamp();
  55     ~timestamp();
  56     void reset();
  57
  58     void start();
  59     void stop();
  60
  61     struct timeval tv_duration() const;
  62     double duration() const;
  63
  64 private:
  65     struct rusage before;
  66     struct rusage after;
  67     struct timeval difference;
  68
  69     static void tv_clear(struct timeval& a);
  70     static double timertod(const struct timeval& a);
  71 };
  72
  73 inline
  74 timestamp::timestamp()
  75 {
  76     reset();
  77 }
  78
  79 inline
  80 timestamp::~timestamp()
  81 {
  82 }
  83
  84 inline
  85 void timestamp::reset()
  86 {
  87     tv_clear(before.ru_utime);
  88     tv_clear(before.ru_stime);
  89     tv_clear(after.ru_utime);
  90     tv_clear(after.ru_stime);
  91     tv_clear(difference);
  92 }
  93
  94 inline
  95 void timestamp::start()
  96 {
  97     getrusage(RUSAGE_SELF, &before);
  98 }
  99
 100 inline
 101 void timestamp::stop()
 102 {
 103     getrusage(RUSAGE_SELF, &after);
 104     difference = difference + ((after.ru_utime + after.ru_stime) -
 105                                (before.ru_utime + before.ru_stime));
 106 }
 107
 108 inline
 109 struct timeval timestamp::tv_duration() const
 110 {
 111     return difference;
 112 }
 113
 114 inline
 115 double timestamp::duration() const
 116 {
 117     return timertod(difference);
 118 }
 119
 120 inline
 121 void timestamp::tv_clear(struct timeval& a)
 122 {
 123 #ifdef HAVE_TIMERCLEAR
 124     timerclear(&a);
 125 #else
 126     tv.sec = tv.usec = 0;
 127 #endif
 128 }
 129
 130 inline
 131 double timestamp::timertod(const struct timeval& a)
 132 {
 133     return a.tv_sec + a.tv_usec / 1e6;
 134 }
 135
 136 #endif // !TIMER_H
 137
 138 // Local variables:
 139 // mode: c++
 140 // End: