Finishing Time

• There are sections associated with setting the time zone and the locale,
• But I am running out of time
• And you can read these.
• But Process Time, 10.7 is somewhat important
  • #include <sys/times.h>
  • clock_t times(struct tms *buffer);

  • struct tms
      {
        clock_t tms_utime;          /* User CPU time.  */
        clock_t tms_stime;          /* System CPU time.  */
    
        clock_t tms_cutime;         /* User CPU time of dead children.  */
        clock_t tms_cstime;         /* System CPU time of dead children.  */
      };
           

  • Returns an arbitrary value that only increases.
  • Think look at clock, note time, look at clock again, subtract difference.
  • Don't think stopwatch.
  • This is returned in clock_ticks
  • sysconf(_SC_CLK_TCK) gives the number of clock ticks per second.
• Look at timeit.C
• C++11 has provided the chrono library
  • reference
  • This is made up of three pieces
    • A clock.
    • A Time point
    • A duration.
  • Clocks:
    • The system_clock is a class that represents the real system clock.
    • The stedy_clock is a class that will never return a lower value than the prevous call.
    • The high_resolution_clock is a class that will return the BEST precision.
  • Time Points are a class that maintains the value of a clock.
  • A duration represents the difference between two time points.
    • hours, minutes, seconds, milliseconds, microseconds, nanoseconds