Struct std.datetime.StopWatch

This class uses a high-performance counter. On Windows systems, it uses QueryPerformanceCounter, and on Posix systems, it uses clock_gettime if available, and gettimeofday otherwise.

But the precision of StopWatch differs from system to system. It is impossible to for it to be the same from system to system since the precision of the system clock varies from system to system, and other system-dependent and situation-dependent stuff (such as the overhead of a context switch between threads) can also affect StopWatch's accuracy.

Constructors

Properties

Methods

Examples

void foo()
{
    StopWatch sw;
    enum n = 100;
    TickDuration[n] times;
    TickDuration last = TickDuration.from!"seconds"(0);
    foreach(i; 0..n)
    {
       sw.start(); //start/resume mesuring.
       foreach(unused; 0..1_000_000)
           bar();
       sw.stop();  //stop/pause measuring.
       //Return value of peek() after having stopped are the always same.
       writeln((i + 1) * 1_000_000, " times done, lap time: ",
               sw.peek().msecs, "[ms]");
       times[i] = sw.peek() - last;
       last = sw.peek();
    }
    real sum = 0;
    // To know the number of seconds,
    // use properties of TickDuration.
    // (seconds, msecs, usecs, hnsecs)
    foreach(t; times)
       sum += t.hnsecs;
    writeln("Average time: ", sum/n, " hnsecs");
}