using System;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.Threading;
namespace Win32
{
   internal class HiPerfTimer
   {
      [DllImport("Kernel32.dll")]
      private static extern bool QueryPerformanceCounter(
         out long lpPerformanceCount);
      [DllImport("Kernel32.dll")]
      private static extern bool QueryPerformanceFrequency(
         out long lpFrequency);
      private long startTime, stopTime;
      private long freq;
      // Constructor
      public HiPerfTimer()
      {
         startTime = 0;
         stopTime = 0;
         if (QueryPerformanceFrequency(out freq) == false)
         {
            // high-performance counter not supported
            throw new Win32Exception();
         }
      }
      // Start the timer
      public void Start()
      {
         // lets do the waiting threads there work
         Thread.Sleep(0);
         QueryPerformanceCounter(out startTime);
      }
      // Stop the timer
      public void Stop()
      {
         QueryPerformanceCounter(out stopTime);
      }
      // Returns the duration of the timer (in seconds)
      public double Duration
      {
         get
         {
            return (double)(stopTime - startTime) / (double) freq;
         }
      }
   }
}