VB.Net Tutorial/Thread/ThreadStatic

ThreadStatic

<source lang="vbnet">Imports System.Threading public class Test

  Shared Dim obj As MyClass1 = new MyClass1
  public Shared Sub Main
              Dim thread1 As New Thread(AddressOf doSomething)
              Dim thread2 As New Thread(AddressOf doSomething)
              Dim thread3 As New Thread(AddressOf doSomething)
              thread1.Start()
              thread2.Start()
              thread3.Start()
  End Sub
  
  Private Shared Sub doSomething()
          Dim i As Integer
          For i = 1 To 3
              obj.SharedData = i
              obj.threadUniqueID = AppDomain.GetCurrentThreadId()
              Console.WriteLine("ID: " & obj.threadUniqueID & ", I:=" & i & ", SharedData: " & obj.SharedData.ToString())
              Thread.CurrentThread.Sleep(250)
          Next
  End Sub

End class Public Class MyClass1

      <ThreadStatic()> Public threadUniqueID As Integer
      Public SharedData As Integer = 0

End Class</source>

ID: 2564, I:=1, SharedData: 1
ID: 3196, I:=1, SharedData: 1
ID: 2656, I:=1, SharedData: 1
ID: 2564, I:=2, SharedData: 2
ID: 3196, I:=2, SharedData: 2
ID: 2656, I:=2, SharedData: 2
ID: 2564, I:=3, SharedData: 3
ID: 3196, I:=3, SharedData: 3
ID: 2656, I:=3, SharedData: 3

ThreadStatic field

<source lang="vbnet">Imports System.Threading Public Class SharedByThread

  <ThreadStatic> Private Shared Count As Integer
  Public Shared Sub Main()
  
     Dim secondThread As New thread(AddressOf Thread2Proc)
     secondThread.Start()
     count = 100
     For ctr As Integer = 0 to 10
        Console.WriteLine("The value of count in the main thread is {0}.", count)
        IncrementCounter(200)
     Next
  End Sub
  Public Shared Sub Thread2Proc()
     count = 0
     For ctr As Integer = 0 to 10
        Console.WriteLine("The value of count in the second thread is {0}.", count)
        IncrementCounter(250)
     Next
  End Sub
  Public Shared Sub IncrementCounter(delay As Integer)
     count +=1
     Thread.Sleep(delay)
  End Sub

End Class</source>

The value of count in the second thread is 0.
The value of count in the main thread is 100.
The value of count in the main thread is 101.
The value of count in the second thread is 1.
The value of count in the main thread is 102.
The value of count in the second thread is 2.
The value of count in the main thread is 103.
The value of count in the second thread is 3.
The value of count in the main thread is 104.
The value of count in the second thread is 4.
The value of count in the main thread is 105.
The value of count in the main thread is 106.
The value of count in the second thread is 5.
The value of count in the main thread is 107.
The value of count in the second thread is 6.
The value of count in the main thread is 108.
The value of count in the second thread is 7.
The value of count in the main thread is 109.
The value of count in the second thread is 8.
The value of count in the main thread is 110.
The value of count in the second thread is 9.
The value of count in the second thread is 10.