C#•9mo ago

✅ Time of method differs between Stopwatch.GetTimestamp and DateTime.Now

Hi there, I have to codes, that differs only in the way that they are recording time of the same operation. It there a big deal that they are once use DataTime and TimeSpan and other Stopwatch.GetTimeStamp?

static void LMaxT()
{
    DateTime startTime, stopTime;
    TimeSpan totalTime = TimeSpan.Zero;
    for (int i = 0; i < NumOfIter ; i++)
    {
        startTime = DateTime.Now;
        bool Present = IsPresent_Linear(sourceTable, sourceTable.Length - 1);
        stopTime = DateTime.Now;

        totalTime += stopTime - startTime;
    }
    TimeSpan lenghtOfCalc = totalTime / NumOfIter;
    Console.Write($"\t{lenghtOfCalc.TotalSeconds.ToString("F4")}s");
}

static void LinearMaxTim()
{
    double ElapsedSeconds;
    long ElapsedTime = 0, MinTime = long.MaxValue, MaxTime = long.MinValue, IterationElapsedTime;
    for (int n = 0; n < (NumOfIter); ++n)
    {
        long StartingTime = Stopwatch.GetTimestamp();
        bool Present = IsPresent_Linear(sourceTable, sourceTable.Length - 1);
        long EndingTime = Stopwatch.GetTimestamp();
        IterationElapsedTime = EndingTime - StartingTime;
        ElapsedTime += IterationElapsedTime;
        if (IterationElapsedTime < MinTime) MinTime = IterationElapsedTime;
        if (IterationElapsedTime > MaxTime) MaxTime = IterationElapsedTime;
    }
    ElapsedTime -= (MinTime + MaxTime);
    ElapsedSeconds = ElapsedTime * (1.0 / (NumOfIter * Stopwatch.Frequency));
    Console.Write("\t" + ElapsedSeconds.ToString("F4")+"s");
}

static void LMaxT()
{
    DateTime startTime, stopTime;
    TimeSpan totalTime = TimeSpan.Zero;
    for (int i = 0; i < NumOfIter ; i++)
    {
        startTime = DateTime.Now;
        bool Present = IsPresent_Linear(sourceTable, sourceTable.Length - 1);
        stopTime = DateTime.Now;

        totalTime += stopTime - startTime;
    }
    TimeSpan lenghtOfCalc = totalTime / NumOfIter;
    Console.Write($"\t{lenghtOfCalc.TotalSeconds.ToString("F4")}s");
}

static void LinearMaxTim()
{
    double ElapsedSeconds;
    long ElapsedTime = 0, MinTime = long.MaxValue, MaxTime = long.MinValue, IterationElapsedTime;
    for (int n = 0; n < (NumOfIter); ++n)
    {
        long StartingTime = Stopwatch.GetTimestamp();
        bool Present = IsPresent_Linear(sourceTable, sourceTable.Length - 1);
        long EndingTime = Stopwatch.GetTimestamp();
        IterationElapsedTime = EndingTime - StartingTime;
        ElapsedTime += IterationElapsedTime;
        if (IterationElapsedTime < MinTime) MinTime = IterationElapsedTime;
        if (IterationElapsedTime > MaxTime) MaxTime = IterationElapsedTime;
    }
    ElapsedTime -= (MinTime + MaxTime);
    ElapsedSeconds = ElapsedTime * (1.0 / (NumOfIter * Stopwatch.Frequency));
    Console.Write("\t" + ElapsedSeconds.ToString("F4")+"s");
}

9 Replies

Angius•9mo ago

Stopwatch will, in general, be the most accurate I believe

TiEmKejOP•9mo ago

Damn, this inaccuracy is big af If it's it

Angius•9mo ago

If you want to benchmark execution time of something, though Benchmark.NET will be the most accurate

TiEmKejOP•9mo ago

Nah, it's just a simple project for University The Prof gave sample with Timestamp, and i was curious why DataTime had this much longer "execution" time

Unknown User•9mo ago

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Petris•9mo ago

you can also do

long start = Stopwatch.GetTimestamp();
// do something
return Stopwatch.GetElapsedTime(start);

long start = Stopwatch.GetTimestamp();
// do something
return Stopwatch.GetElapsedTime(start);

and you need no objects for it

Unknown User•9mo ago

Message Not Public

jcotton42•9mo ago

TIL that method added .NET 7 neat

Unknown User•9mo ago

Message Not Public

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✅ Time of method differs between Stopwatch.GetTimestamp and DateTime.Now