En mi computadora, el cronómetro devuelve valores demasiado bajos. Por ejemplo, 200 ms cuando especifiqué Thread.Sleep(1000)
. Se supone que el programa debe esperar 1 segundo. También probé con ManualResetEvent.WaitOne(1000)
y obtuve los mismos resultados. Ambos framework 2.0 y 3.0 dan este extraño comportamiento. Estoy ejecutando Windows XP SP3 con .NET Framework 3.5 SP1..NET System.Diagnostics.Stopwatch issue (devuelve valores demasiado bajos)
Este es el resultado de mis pruebas (código de abajo):
1000 ms for DateTime.Now.Ticks
0201 ms for Stopwatch.ElapsedTicks
0142 ms for Stopwatch.ElapsedMilliseconds
0139 ms for Stopwatch.ElapsedTicks after Reset
0264 ms for Stopwatch.ElapsedTicks setting ThreadAffinity
0151 ms for Stopwatch.ElapsedTicks setting ProcessorAffinity (and more)
0371 ms for Stopwatch.ElapsedTicks with Syncronized object
Done!
// Program.cs archivo
class Program
{
static void Main(string[] args)
{
StopWatchTest.Go();
Console.WriteLine("Done!");
Console.ReadLine();
}
}
// StopWatchTest.cs clase
internal static class StopWatchTest
{
public const int SleepTime = 1000;
public static void Go()
{
#region Test #0 with DateTime.Now.Ticks
long startTick = DateTime.Now.Ticks;
Thread.Sleep(SleepTime);
long stopTick = DateTime.Now.Ticks;
long elapsedDt = (stopTick - startTick) * 100;
Display((int)(elapsedDt/1000/1000), "DateTime.Now.Ticks");
#endregion Test #0 with DateTime.Now.Ticks
Stopwatch watch = Stopwatch.StartNew();
long frequency = Stopwatch.Frequency;
double nanosecPerTick = (1000.0 * 1000.0 * 1000.0)/frequency;
#region Test #1 with Stopwatch.ElapsedTicks
startTick = watch.ElapsedTicks;
Thread.Sleep(SleepTime);
stopTick = watch.ElapsedTicks;
double elapsedSw = (stopTick - startTick) * nanosecPerTick;
Display((int)(elapsedSw/1000/1000), "Stopwatch.ElapsedTicks");
#endregion Test #1 with Stopwatch.ElapsedTicks
#region Test #2 with Stopwatch.ElapsedMilliseconds
startTick = watch.ElapsedMilliseconds;
Thread.Sleep(SleepTime);
stopTick = watch.ElapsedMilliseconds;
Display((int)(stopTick - startTick), "Stopwatch.ElapsedMilliseconds");
#endregion Test #2 with Stopwatch.ElapsedMilliseconds
#region Test #3 with Stopwatch.ElapsedTicks after Reset
watch.Stop();
watch.Reset();
watch.Start();
startTick = watch.ElapsedTicks;
Thread.Sleep(SleepTime);
stopTick = watch.ElapsedTicks;
elapsedSw = (stopTick - startTick) * nanosecPerTick;
Display((int)(elapsedSw/1000/1000), "Stopwatch.ElapsedTicks after Reset");
#endregion Test #3 with Stopwatch.ElapsedTicks after Reset
#region Test #4 with Stopwatch.ElapsedTicks and ThreadAffinity
Thread.BeginThreadAffinity();
startTick = watch.ElapsedTicks;
Thread.Sleep(SleepTime);
stopTick = watch.ElapsedTicks;
elapsedSw = (stopTick - startTick) * nanosecPerTick;
Display((int)(elapsedSw/1000/1000), "Stopwatch.ElapsedTicks setting ThreadAffinity");
Thread.EndThreadAffinity();
#endregion Test #4 with Stopwatch.ElapsedTicks and ThreadAffinity
#region Test #5 with Stopwatch.ElapsedTicks and ProcessorAffinity (and more)
const int affinity = 0x0001;
Process proc = Process.GetCurrentProcess();
proc.ProcessorAffinity = new IntPtr(affinity);
proc.PriorityClass = ProcessPriorityClass.High;
ProcessThreadCollection ptc = proc.Threads;
foreach (ProcessThread pt in ptc)
{
pt.IdealProcessor = 0;
pt.ProcessorAffinity = new IntPtr(affinity);
}
Thread.CurrentThread.Priority = ThreadPriority.Highest;
startTick = watch.ElapsedTicks;
Thread.Sleep(SleepTime);
stopTick = watch.ElapsedTicks;
elapsedSw = (stopTick - startTick) * nanosecPerTick;
Display((int)(elapsedSw/1000/1000), "Stopwatch.ElapsedTicks setting ProcessorAffinity (and more)");
#endregion Test #5 with ProcessorAffinity and more
#region Test #6 with Syncronized object
elapsedSw = new SyncTimer().Go();
Display((int)(elapsedSw/1000/1000), "Stopwatch.ElapsedTicks with Syncronized object");
#endregion Test #6 with Syncronized object
}
private static void Display(int milliseconds, string testName)
{
Console.WriteLine("{0:0000} ms for {1}", milliseconds, testName);
}
}
[Synchronization]
internal class SyncTimer : ContextBoundObject
{
[MethodImpl(MethodImplOptions.Synchronized)]
public double Go()
{
Stopwatch.StartNew();
long frequency = Stopwatch.Frequency;
double nanosecPerTick = (1000.0 * 1000.0 * 1000.0)/frequency;
long startTick = Stopwatch.GetTimestamp();
Thread.Sleep(StopWatchTest.SleepTime);
long stopTick = Stopwatch.GetTimestamp();
return (stopTick - startTick) * nanosecPerTick;
}
}
@ user633578, hay un error en su código. Debe usar una instancia de cronómetro por prueba. – acoolaum
Tendrá que llevar su máquina al médico de la BIOS. –
No vi ninguna limitación sobre volver a usar la misma instancia de Cronómetro. Por cierto, la primera prueba no arroja un valor válido. – Ducharme