CODEWITHSUNDEEP
asp.netvb.netmultithreadingsession
Christopher
Christopher

Reputation: 788

Are session variables shared across threads?

I am working on a VB.Net project, and I want a fast and dirty way of having a second thread preform some function, then store some variable outcome to the session. Then I want to access that variable from the first thread (in the same session of course).

Here is an example of the code...

Button#1

Sub button_Click1(byVal sender As Object, ByVal e As Event Args)

textfield1.Visible = False
lable2.Visible = True
textfield2.Visible = True
button_Click2.Visible = True

Dim thread2 As New System.Threading.Thread(AddressOf foothread)
thread2.Start(textfield1.Text.ToString)

End Sub

Button#2

Sub button_Click2(byVal sender As Object, ByVal e As Event Args)
If(textfield2.Text = "is cool" And System.Web.HttpContext.Current.Session("myBool") = true) Then
 lable2 = "You're right!"
 else
 lable2 = "???"
 end If

Thread #2

Public Sub thread2(ByVal str1 As String)

If(srt1 = "Stack/Flow") Then
System.Web.HttpContext.Current.Session("myBool") = true 
Else
System.Web.HttpContext.Current.Session("myBool") = false
End If

End Sub

Obviously this is not a real production example, I am running a lengthy query in the thread which will return my session variable (lengthy due to network traffic to that box)

Is this possible? Is there a better way? Will this even work? New to multithreaded applications.

Thanks!

Upvotes: 0

Views: 1208

Answers (1)

Guffa
Guffa

Reputation: 700910

No, that doesn't work. The second thread doesn't have a HTTP context, only threads that run to handle requests have a HTTP context.

Youcan make a class for the method to run in the second thread, and add any input and output data as members in the class:

Public Class Thread2Class

  Public Str1 As String    
  Public MyBool As Boolean

  Public Sub Run()

    If Str1 = "Stack/Flow" Then
      MyBool = True 
    Else
      MyBool = False
    End If

  End Sub

End Class

Create an instance of the class, set the input data, and start the thread:

Dim thread2 As New Thread2Class
thread2.Str1 = Lable1.Text.ToString
Dim thread2 As New System.Threading.Thread(AddressOf thread2.Run)
thread2.Start()

Keep the reference to the class, so that you can read the result from the member when the thread has finished:

Dim result As Boolean = thread2.MyBool

Upvotes: 1

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