Multithreading in Visual Basic.NET

[بابک زواری]

The sample code demonstrates multithreading in VB.NET. The application creates two
threads that are accesing the same account amount.This reqires synchronization of
threads, which is accomplished in VB.NET through use of the Monitor object of the the
Thread class.
To run this code, create a new Console application in Visual Basic.NET, paste the code
into the code window, right click the project name and select project properties, and
change the startup object to Thread Sample.

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

 

 

Imports System

Imports System.Threading

Public Module ThreadSample

    Public Balance As Integer = 1000

    Sub Main()

        Dim account As Account = New Account()

        Dim depositeBalance1 As DepositeBalance = New _

                DepositeBalance(account, 1000, "Customer 1")

        Dim depositeBalance2 As DepositeBalance = New _

           DepositeBalance(account, 1000, "Customer 2")

        Dim t1 As Thread = New _

             Thread(AddressOf depositeBalance1.DepositeAmount)

        Dim t2 As Thread = New _

        Thread(AddressOf depositeBalance2.DepositeAmount)

        t1.Start()

        t2.Start()

        Try

            t1.Join()

            t2.Join()

        Catch e As Exception

            Console.Write(e.ToString())

        Finally

            'Do Nothing

        End Try

    End Sub

    Public Class Account

        Private balanceAmount As Integer

        Public Sub Deposite(ByVal amount As Integer, _

            ByVal message As String)

            Console.Write(message & _

                " Depositing Amount " & amount)

            Console.Write(message & " Checking Previous Balance")

            Monitor.Enter(Me)

            balanceAmount = getBalance()

            Console.Write(message & _

                " Previous Balance in Account " & balanceAmount)

            balanceAmount += amount

            Console.Write(message & _

               " Updating Balance in Account ")

            setBalance(balanceAmount)

            Monitor.Exit(Me)

            Console.Write(message & " Update Balance " & Balance)

            

        End Sub

        Private Function getBalance() As Integer

            Try

                Thread.sleep(1000)

            Catch e As Exception

                Console.Write(e.ToString())

            Finally

                'Do Nothing

            End Try

            Return Balance

        End Function

        

        Private Sub setBalance(ByVal amount As Integer)

            Try

                Thread.sleep(1000)

            Catch e As Exception

                Console.Write(e.ToString())

            Finally

                'Do Nothing

            End Try

            Balance = amount

        End Sub

    End Class

    

    Public Class DepositeBalance

        Private account As Account

        Private amount As Integer

        Private message As String

        

        Public Sub new(ByRef account As Account, _

         ByVal amount As Integer, ByVal message As String)

            MyBase.New()

            Me.account = account

            Me.amount = amount

            Me.message = message

        End Sub

        Public Sub DepositeAmount()

            Account.Deposite(amount, message)

        End Sub

    End Class

End Module