TimeCounter.cs :  » GUI » TreeViewAdv » Aga » Controls » C# / CSharp Open Source

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Diagnostics.CodeAnalysis;

namespace Aga.Controls{
  /// <summary>
  /// High resolution timer, used to test performance
  /// </summary>
  public static class TimeCounter
  {
    private static Int64 _start;

    /// <summary>
    /// Start time counting
    /// </summary>
    public static void Start()
    {
      _start = 0;
      QueryPerformanceCounter(ref _start);
    }

    public static Int64 GetStartValue()
    {
      Int64 t = 0;
      QueryPerformanceCounter(ref t);
      return t;
    }

    /// <summary>
    /// Finish time counting
    /// </summary>
    /// <returns>time in seconds elapsed from Start till Finish  </returns>
    public static double Finish()
    {
      return Finish(_start);
    }

    public static double Finish(Int64 start)
    {
      Int64 finish = 0;
      QueryPerformanceCounter(ref finish);

      Int64 freq = 0;
      QueryPerformanceFrequency(ref freq);
      return (finish - start) / (double)freq;
    }

    [DllImport("Kernel32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool QueryPerformanceCounter(ref Int64 performanceCount);

    [DllImport("Kernel32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool QueryPerformanceFrequency(ref Int64 frequency);
  }
}