PerformanceCounter.IncrementBy(Int64) PerformanceCounter.IncrementBy(Int64) PerformanceCounter.IncrementBy(Int64) PerformanceCounter.IncrementBy(Int64) Method

Definition

Increments or decrements the value of the associated performance counter by a specified amount through an efficient atomic operation.

public:
 long IncrementBy(long value);
public long IncrementBy (long value);
member this.IncrementBy : int64 -> int64
Public Function IncrementBy (value As Long) As Long

Parameters

value
Int64 Int64 Int64 Int64

The value to increment by. (A negative value decrements the counter.)

Returns

The new counter value.

Exceptions

The counter is read-only, so the application cannot increment it.

-or-

The instance is not correctly associated with a performance counter.

-or-

The InstanceLifetime property is set to Process when using global shared memory.

An error occurred when accessing a system API.

Examples

The following code example demonstrates how to use the IncrementBy method to add increments to a counter. This code example is part of a larger example for the PerformanceCounter class.

void CollectSamples( ArrayList^ samplesList, PerformanceCounter^ PC, PerformanceCounter^ BPC )
{
   Random^ r = gcnew Random( DateTime::Now.Millisecond );

   // Loop for the samples.
   for ( int j = 0; j < 100; j++ )
   {
      int value = r->Next( 1, 10 );
      Console::Write( "{0} = {1}", j, value );
      PC->IncrementBy( value );
      BPC->Increment();
      if ( (j % 10) == 9 )
      {
         OutputSample( PC->NextSample() );
         samplesList->Add( PC->NextSample() );
      }
      else
            Console::WriteLine();
      System::Threading::Thread::Sleep( 50 );
   }
}
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 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

Remarks

You can write only to custom counters. All system counters are read-only.

Note

The Increment, IncrementBy, and Decrement methods use interlocks to update the counter value. This helps keep the counter value accurate in multithreaded or multiprocess scenarios, but also results in a performance penalty. If you do not need the accuracy that interlocked operations provide, you can update the RawValue property directly for up to a 5 times performance improvement. However, in multithreaded scenarios, some updates to the counter value might be ignored, resulting in inaccurate data.

Note

If the value for the InstanceLifetime property is Process and the performance counter category was created with .NET Framework version 1.0 or 1.1, an InvalidOperationException is thrown. Performance counter categories created with earlier versions use global shared memory, and the value for InstanceLifetime must be Global. If the category is not used by applications running on versions 1.0 or 1.1 of the .NET Framework, delete and recreate the category.

Security

PerformanceCounterPermission
for writing the performance counter category if the ReadOnly property is false. Associated enumeration: Write.

Applies to