PerformanceCounter.RawValue Propiedad

Definición

Espacio de nombres:

System.Diagnostics

Ensamblado:

System.Diagnostics.PerformanceCounter.dll

Source:

PerformanceCounter.cs

Obtiene o establece el valor sin calcular o sin procesar de este contador.

public:
 property long RawValue { long get(); void set(long value); };

public long RawValue { get; set; }

member this.RawValue : int64 with get, set

Public Property RawValue As Long

Valor de propiedad

Int64

Valor sin procesar del contador.

Excepciones

InvalidOperationException

Está intentando establecer el valor sin procesar del contador, pero el contador es de solo lectura.

O bien

La instancia no está asociada correctamente a un contador de rendimiento.

O bien

La InstanceLifetime propiedad se establece en Process cuando se usa la memoria compartida global.

Win32Exception

Error al acceder a una API del sistema.

UnauthorizedAccessException

Código que se ejecuta sin privilegios administrativos intenta leer un contador de rendimiento.

Ejemplos

En el ejemplo siguiente se usa la CounterSample clase para mostrar el valor de la RawValue propiedad para un contador.

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Diagnostics;

public class App
{
    private static PerformanceCounter avgCounter64Sample;
    private static PerformanceCounter avgCounter64SampleBase;

    public static void Main()
    {
        ArrayList samplesList = new ArrayList();

        // If the category does not exist, create the category and exit.
        // Performance counters should not be created and immediately used.
        // There is a latency time to enable the counters, they should be created
        // prior to executing the application that uses the counters.
        // Execute this sample a second time to use the category.
        if (SetupCategory())
            return;
        CreateCounters();
        CollectSamples(samplesList);
        CalculateResults(samplesList);
    }

    private static bool SetupCategory()
    {
        if ( !PerformanceCounterCategory.Exists("AverageCounter64SampleCategory") )
        {

            CounterCreationDataCollection counterDataCollection = new CounterCreationDataCollection();

            // Add the counter.
            CounterCreationData averageCount64 = new CounterCreationData();
            averageCount64.CounterType = PerformanceCounterType.AverageCount64;
            averageCount64.CounterName = "AverageCounter64Sample";
            counterDataCollection.Add(averageCount64);

            // Add the base counter.
            CounterCreationData averageCount64Base = new CounterCreationData();
            averageCount64Base.CounterType = PerformanceCounterType.AverageBase;
            averageCount64Base.CounterName = "AverageCounter64SampleBase";
            counterDataCollection.Add(averageCount64Base);

            // Create the category.
            PerformanceCounterCategory.Create("AverageCounter64SampleCategory",
                "Demonstrates usage of the AverageCounter64 performance counter type.",
                PerformanceCounterCategoryType.SingleInstance, counterDataCollection);

            return(true);
        }
        else
        {
            Console.WriteLine("Category exists - AverageCounter64SampleCategory");
            return(false);
        }
    }

    private static void CreateCounters()
    {
        // Create the counters.

        avgCounter64Sample = new PerformanceCounter("AverageCounter64SampleCategory",
            "AverageCounter64Sample",
            false);


        avgCounter64SampleBase = new PerformanceCounter("AverageCounter64SampleCategory",
            "AverageCounter64SampleBase",
            false);

        avgCounter64Sample.RawValue=0;
        avgCounter64SampleBase.RawValue=0;
    }
    private static void CollectSamples(ArrayList samplesList)
    {

        Random r = new Random( DateTime.Now.Millisecond );

        // Loop for the samples.
        for (int j = 0; j < 100; j++)
        {

            int value = r.Next(1, 10);
            Console.Write(j + " = " + value);

            avgCounter64Sample.IncrementBy(value);

            avgCounter64SampleBase.Increment();

            if ((j % 10) == 9)
            {
                OutputSample(avgCounter64Sample.NextSample());
                samplesList.Add( avgCounter64Sample.NextSample() );
            }
            else
            {
                Console.WriteLine();
            }

            System.Threading.Thread.Sleep(50);
        }
    }

    private static void CalculateResults(ArrayList samplesList)
    {
        for(int i = 0; i < (samplesList.Count - 1); i++)
        {
            // Output the sample.
            OutputSample( (CounterSample)samplesList[i] );
            OutputSample( (CounterSample)samplesList[i+1] );

            // Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " +
                CounterSampleCalculator.ComputeCounterValue((CounterSample)samplesList[i],
                (CounterSample)samplesList[i+1]) );

            // Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " +
                MyComputeCounterValue((CounterSample)samplesList[i],
                (CounterSample)samplesList[i+1]) );
        }
    }

    //++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++
    //    Description - This counter type shows how many items are processed, on average,
    //        during an operation. Counters of this type display a ratio of the items
    //        processed (such as bytes sent) to the number of operations completed. The
    //        ratio is calculated by comparing the number of items processed during the
    //        last interval to the number of operations completed during the last interval.
    // Generic type - Average
    //      Formula - (N1 - N0) / (D1 - D0), where the numerator (N) represents the number
    //        of items processed during the last sample interval and the denominator (D)
    //        represents the number of operations completed during the last two sample
    //        intervals.
    //    Average (Nx - N0) / (Dx - D0)
    //    Example PhysicalDisk\ Avg. Disk Bytes/Transfer
    //++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++
    private static Single MyComputeCounterValue(CounterSample s0, CounterSample s1)
    {
        Single numerator = (Single)s1.RawValue - (Single)s0.RawValue;
        Single denomenator = (Single)s1.BaseValue - (Single)s0.BaseValue;
        Single counterValue = numerator / denomenator;
        return(counterValue);
    }

    // Output information about the counter sample.
    private static void OutputSample(CounterSample s)
    {
        Console.WriteLine("\r\n+++++++++++");
        Console.WriteLine("Sample values - \r\n");
        Console.WriteLine("   BaseValue        = " + s.BaseValue);
        Console.WriteLine("   CounterFrequency = " + s.CounterFrequency);
        Console.WriteLine("   CounterTimeStamp = " + s.CounterTimeStamp);
        Console.WriteLine("   CounterType      = " + s.CounterType);
        Console.WriteLine("   RawValue         = " + s.RawValue);
        Console.WriteLine("   SystemFrequency  = " + s.SystemFrequency);
        Console.WriteLine("   TimeStamp        = " + s.TimeStamp);
        Console.WriteLine("   TimeStamp100nSec = " + s.TimeStamp100nSec);
        Console.WriteLine("++++++++++++++++++++++");
    }
}

Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _

Public Class App

    Private Shared avgCounter64Sample As PerformanceCounter
    Private Shared avgCounter64SampleBase As PerformanceCounter


    Public Shared Sub Main()

        Dim samplesList As New ArrayList()
        'If the category does not exist, create the category and exit.
        'Performance counters should not be created and immediately used.
        'There is a latency time to enable the counters, they should be created
        'prior to executing the application that uses the counters.
        'Execute this sample a second time to use the counters.
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If

    End Sub

    Private Shared Function SetupCategory() As Boolean
        If Not PerformanceCounterCategory.Exists("AverageCounter64SampleCategory") Then

            Dim counterDataCollection As New CounterCreationDataCollection()

            ' Add the counter.
            Dim averageCount64 As New CounterCreationData()
            averageCount64.CounterType = PerformanceCounterType.AverageCount64
            averageCount64.CounterName = "AverageCounter64Sample"
            counterDataCollection.Add(averageCount64)

            ' Add the base counter.
            Dim averageCount64Base As New CounterCreationData()
            averageCount64Base.CounterType = PerformanceCounterType.AverageBase
            averageCount64Base.CounterName = "AverageCounter64SampleBase"
            counterDataCollection.Add(averageCount64Base)

            ' Create the category.
            PerformanceCounterCategory.Create("AverageCounter64SampleCategory", _
               "Demonstrates usage of the AverageCounter64 performance counter type.", _
                      PerformanceCounterCategoryType.SingleInstance, counterDataCollection)

            Return True
        Else
            Console.WriteLine("Category exists - AverageCounter64SampleCategory")
            Return False
        End If
    End Function 'SetupCategory

    Private Shared Sub CreateCounters()
        ' Create the counters.

        avgCounter64Sample = New PerformanceCounter("AverageCounter64SampleCategory", "AverageCounter64Sample", False)

        avgCounter64SampleBase = New PerformanceCounter("AverageCounter64SampleCategory", "AverageCounter64SampleBase", False)

        avgCounter64Sample.RawValue = 0
        avgCounter64SampleBase.RawValue = 0
    End Sub

    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Loop for the samples.
        Dim j As Integer
        For j = 0 To 99

            Dim value As Integer = r.Next(1, 10)
            Console.Write(j.ToString() + " = " + value.ToString())

            avgCounter64Sample.IncrementBy(value)

            avgCounter64SampleBase.Increment()

            If j Mod 10 = 9 Then
                OutputSample(avgCounter64Sample.NextSample())
                samplesList.Add(avgCounter64Sample.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub

    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))
            OutputSample(CType(samplesList((i + 1)), CounterSample))

            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())
        Next i
    End Sub

    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++
    '	Description - This counter type shows how many items are processed, on average,
    '		during an operation. Counters of this type display a ratio of the items 
    '		processed (such as bytes sent) to the number of operations completed. The  
    '		ratio is calculated by comparing the number of items processed during the 
    '		last interval to the number of operations completed during the last interval. 
    ' Generic type - Average
    '  	Formula - (N1 - N0) / (D1 - D0), where the numerator (N) represents the number 
    '		of items processed during the last sample interval and the denominator (D) 
    '		represents the number of operations completed during the last two sample 
    '		intervals. 
    '	Average (Nx - N0) / (Dx - D0)  
    '	Example PhysicalDisk\ Avg. Disk Bytes/Transfer 
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++
    Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single]
        Dim numerator As [Single] = CType(s1.RawValue, [Single]) - CType(s0.RawValue, [Single])
        Dim denomenator As [Single] = CType(s1.BaseValue, [Single]) - CType(s0.BaseValue, [Single])
        Dim counterValue As [Single] = numerator / denomenator
        Return counterValue
    End Function 'MyComputeCounterValue

    ' Output information about the counter sample.
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine(("   BaseValue        = " + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub
End Class

Comentarios

Si el tipo de contador es de tamaño de 32 bits e intenta establecer esta propiedad en un valor demasiado grande para ajustarse, la propiedad trunca el valor en 32 bits. Al leer contadores personalizados en el equipo local, el uso de la RawValue propiedad en lugar de un valor calculado puede producir un rendimiento significativamente mejor en escenarios en los que el valor sin procesar es suficiente.

Si el contador que está leyendo es de solo lectura, al obtener la RawValue propiedad se muestra el contador en el momento en que se llama a la propiedad . Esta acción equivale a realizar una llamada inicial al NextSample método . Si posteriormente llama a NextSample, puede realizar cálculos en los valores devueltos por ambas llamadas.

Dado que los contadores del sistema son de solo lectura, puede obtener pero no establecer sus valores sin procesar.

Nota:

Los Incrementmétodos , IncrementByy Decrement usan interbloqueos para actualizar el valor del contador. Esto ayuda a mantener el valor de contador preciso en escenarios multiproceso o multiproceso, pero también produce una penalización de rendimiento. Si no necesita la precisión que proporcionan las operaciones interbloqueadas, puede actualizar la RawValue propiedad directamente para una mejora del rendimiento de hasta cinco veces. Sin embargo, en escenarios multiproceso, es posible que se omitan algunas actualizaciones del valor del contador, lo que da lugar a datos inexactos.

Nota:

Si el valor de la InstanceLifetime propiedad es Process y la categoría del contador de rendimiento se creó con .NET Framework versión 1.0 o 1.1, se produce una InvalidOperationException excepción . Las categorías de contadores de rendimiento creadas con versiones anteriores usan memoria compartida global y el valor de InstanceLifetime debe ser Global. Si las aplicaciones que se ejecutan en las versiones 1.0 o 1.1 de .NET Framework no usan la categoría, elimine y vuelva a crear la categoría.

Nota:

Para leer contadores de rendimiento en Windows Vista, Windows XP Professional x64 Edition o Windows Server 2003, debe ser miembro del grupo Usuarios del Monitor de rendimiento o tener privilegios administrativos.

Para evitar tener que elevar sus privilegios para acceder a los contadores de rendimiento en Windows Vista, agréguese al grupo Usuarios del Monitor de rendimiento.

En Windows Vista, el Control de cuentas de usuario (UAC) determina los privilegios de un usuario. Si es miembro del grupo Administradores integrados, se le asignan dos tokens de acceso en tiempo de ejecución: un token de acceso de usuario estándar y un token de acceso de administrador. De forma predeterminada, está en el rol de usuario estándar. Para ejecutar el código que accede a los contadores de rendimiento, primero debe elevar sus privilegios de usuario estándar a administrador. Puede hacerlo al iniciar una aplicación haciendo clic con el botón derecho en el icono de la aplicación e indicando que desea ejecutar como administrador.