How to Get CPU Usage Per Thread

Category:

System/API

Type:

Classes

Difficulty:

Intermediate

Author:

Anonymous

Version Compatibility: Visual Basic.NET

More information:

I searched all over the internet, and found little or no help. No one seemed to have any code for this, and it's not so arcane a subject that it should be so hard to find. If you are writing a multi-threaded app, then at some point you're going to want to know how much CPU time each thread is using, so you can optimize it accordingly. This is a little helper class I wrote to handle that problem. You provide the class a native thread id or just Dim it within the thread you want to watch. The CPUtimer.CPUusage variable is a short representing the percentage of CPU used by this thread. I hope this saves someone some time. This took me way too long.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
Imports System.Diagnostics Imports System.Threading

Code:

Public Class ThreadCPUusageWatcher
        Private threadID As Int16
        Private WatcherRunning As Boolean = False
        Private th1 As Thread
        Private Percentage As Long

Public Sub New()
            threadID = AppDomain.GetCurrentThreadId
        End Sub

Public Sub New(ByVal NativeThreadID As Int16)
            threadID = NativeThreadID
        End Sub

Private Function GetCurrentNativeThreadID() As Int16
            GetCurrentNativeThreadID = AppDomain.GetCurrentThreadId
        End Function

' Set the native ID of a process thread to be watched, or get your native thread id
        Public Property NativeThreadID() As Int16
            Get
                Return GetCurrentNativeThreadID()
            End Get
            Set(ByVal value As Int16)
                threadID = value
            End Set
        End Property
        Public ReadOnly Property IsRunning() As Boolean
            Get
                Return WatcherRunning
            End Get
        End Property

Public ReadOnly Property CPUusage() As Long
            Get
                Return Percentage
            End Get
        End Property

Public Sub StopWatcher()
            WatcherRunning = False
        End Sub
        Public Sub Start()
            th1 = New System.Threading.Thread(AddressOf StartWatcher)
            th1.Start()
        End Sub
        Private Sub StartWatcher()
            Dim tx As System.Diagnostics.ProcessThreadCollection
            Dim t, tId As Int16
            Dim CPUtimeEnd, CPUtimeStart As Double

tx = System.Diagnostics.Process.GetCurrentProcess().Threads
            tId = 0

For t = 0 To tx.Count - 1
                If tx.Item(t).Id = threadID Then
                    tId = t
                End If
            Next

If tId = 0 Then
                MsgBox("Thread could not be found.")
                Exit Sub
            End If

WatcherRunning = True

Try
                Do While WatcherRunning = True

CPUtimeStart = tx.Item(tId).TotalProcessorTime.Milliseconds
                    Thread.Sleep(500)
                    CPUtimeEnd = tx.Item(tId).TotalProcessorTime.Milliseconds

If (CPUtimeEnd > CPUtimeStart) Or (CPUtimeEnd = CPUtimeStart) Then
                        Percentage = CPUtimeEnd - CPUtimeStart
                        Percentage = Percentage / 5
                        If Percentage > 100 Then Percentage = 100
                    End If

Loop
            Catch ex As Exception
                MsgBox(ex.Message)
            End Try

WatcherRunning = False
        End Sub

End Class

'' Usage example ################
Dim CPUtimer As New ThreadCPUusageWatcher
        Dim T As Long

CPUtimer.Start()

Do While TestRun = True
            For T = 1 To 6000
                Thread1txt = CPUtimer.CPUusage.ToString
            Next
            Thread.Sleep(1)
        Loop

CPUtimer.StopWatcher()