Question

In my ASP.NET Web Service I’ve included a module in which their are Public declared variables. Will they be thread-safe? Will they get mixed up upon simultaneous calls?

Those variables are mostly DatsSet, DataTable and SQLDataAdapter..

Partial code of the module:

Imports System.Data.OleDb
Imports System.Diagnostics

Module modCommon

    Public bDoLog As Boolean
    Public sCurrentODBC As String
    Public cn As SqlConnection
    Public Query1ds As DataSet
    Public Query1 As DataTable
    Public Query1adapter As SqlDataAdapter

---

@scripni

Thanks, as I’m not familiary with your suggestions, I will move everything locally.

Additionally, will the following variables be thread-safe?:

[ToolboxItem(False)]_
Public Class Service1 
     Inherits System.Web.Services.WebService 

     Dim sName As String 
     Dim sCurrentPath As String 

     [WebMethod()]_
     Public Function Capture(ByVal sPath As String) As String 
          sName = "Joe"
     End Function 
End Class 

Answer 1

If you’re using web services than yes, you will have concurency problems when multiple services will try to access the same resource, and SqlConnection is definetly a resource you don’t want shared.

You should make sure that you don’t have simultaneous calls to the properties (for ex. by wrapping the fields with getters / setters and implementing locks in those methods) or by moving the code to a class and instantiating that class whenever you need it.