PerformanceCounter.RawValue Propriedade
Definição
Importante
Algumas informações dizem respeito a um produto pré-lançado que pode ser substancialmente modificado antes de ser lançado. A Microsoft não faz garantias, de forma expressa ou implícita, em relação à informação aqui apresentada.
Obtém ou define o valor bruto, ou não calculado, deste contador.
public:
property long RawValue { long get(); void set(long value); };
[System.ComponentModel.Browsable(false)]
public long RawValue { get; set; }
[<System.ComponentModel.Browsable(false)>]
member this.RawValue : int64 with get, set
Public Property RawValue As Long
Valor de Propriedade
O valor bruto do contador.
- Atributos
Exceções
Estás a tentar definir o valor bruto do contador, mas o contador é só de leitura.
-ou-
A instância não está corretamente associada a um contador de desempenho.
-ou-
A InstanceLifetime propriedade é definida para Process quando se utiliza memória partilhada global.
Ocorreu um erro ao aceder a uma API do sistema.
Código que está a executar sem privilégios administrativos tentou ler um contador de desempenho.
Exemplos
O exemplo seguinte usa a CounterSample classe para mostrar o valor da RawValue propriedade para um 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
Observações
Se o tipo de contador for de 32 bits e tentares definir esta propriedade para um valor demasiado grande para caber, a propriedade trunca o valor para 32 bits. Ao ler contadores personalizados no computador local, usar a RawValue propriedade em vez de um valor calculado pode produzir um desempenho significativamente melhor em cenários onde o valor bruto é suficiente.
Se o contador que está a ler for só de leitura, obter a RawValue propriedade amostra o contador no momento em que a propriedade é chamada. Esta ação equivale a fazer uma chamada inicial ao NextSample método. Se posteriormente chamar NextSample, pode fazer cálculos sobre os valores que ambas as chamadas devolveram.
Como os contadores do sistema são apenas de leitura, podes obter mas não definir os seus valores brutos.
Note
Os Incrementmétodos , IncrementBy, e Decrement usam bloqueios para atualizar o valor do contador. Isto ajuda a manter o valor contador preciso em cenários multithreaded ou multiprocesso, mas também resulta numa penalização de desempenho. Se não precisar da precisão que as operações interligadas proporcionam, pode atualizar a RawValue propriedade diretamente para uma melhoria de desempenho até 5 vezes. No entanto, em cenários multithreaded, algumas atualizações ao valor contador podem ser ignoradas, resultando em dados imprecisos.
Note
Se o valor da propriedade InstanceLifetime for Process e a categoria contador de desempenho foi criada com .NET Framework versão 1.0 ou 1.1, é lançado um InvalidOperationException. As categorias de contadores de desempenho criadas com versões anteriores usam memória partilhada global, e o valor para InstanceLifetime deve ser Global. Se a categoria não for usada por aplicações a correr nas versões 1.0 ou 1.1 do .NET Framework, elimine e recrie a categoria.
Note
Para ler contadores de desempenho no Windows Vista, Windows XP Professional x64 Edition ou Windows Server 2003, deve ser membro do grupo Performance Monitor Users ou ter privilégios administrativos.
Para evitar ter de elevar os seus privilégios para aceder a contadores de desempenho no Windows Vista, adicione-se ao grupo Performance Monitor Users.
No Windows Vista, o Controle de Conta de Usuário (UAC) determina os privilégios de um usuário. Se for membro do grupo Administradores Incorporados, é-lhe atribuídos dois tokens de acesso em tempo de execução: um token de acesso de utilizador padrão e um token de acesso de administrador. Por padrão, você está na função de usuário padrão. Para executar o código que acede aos contadores de desempenho, deve primeiro elevar os seus privilégios de utilizador padrão a administrador. Você pode fazer isso ao iniciar um aplicativo clicando com o botão direito do mouse no ícone do aplicativo e indicando que deseja executar como administrador.