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How to ensure instances of class finish before main terminates?
Imports System
Imports System.Threading
Imports System.Collections.Generic
Module Module1
    Private raceTrack As New List(Of RaceCar)
    Sub Main()
        CreateRace()
        'Main() would quit when the 5 car objects are created =[
        'How do I make sure Main will not exit until all racecars are done?
    End Sub

    Sub CreateRace()
        For index As Integer = 1 to 5
            raceTrack.Add(new RaceCar(index))
        Next
    End Sub

    Public Class RaceCar
        Private testThread as Thread =  New Thread(AddressOf StartEngine)
        Private carId as Integer
        Public Sub New(ByVal carNumber as Integer)
            me.carId = carNumber
            Me.TestThread.Start()
            Me.TestThread.Join()
        End Sub

        Public Sub StartEngine()
            Console.WriteLine(String.Format("Car#{0} is going!", Me.carId))
            Thread.Sleep(100*Me.carId)
            Console.WriteLine(String.Format("Car#{0} is DONE!", Me.carId))
        End Sub

    End Class

End Module

Public Sub New(ByVal carNumber as Integer)
        me.carId = carNumber
        Me.TestThread.Start()
        Me.TestThread.Join()
    End Sub

Public Sub JoinThread()
    Me.TestThread.Join()
End Sub

Sub CreateRace()
    For index As Integer = 1 to 5
        raceTrack.Add(new RaceCar(index))
    Next

    // other work maybe?

    For Each car As RaceCar In raceTrack
        car.JoinThread()
    Next
End Sub

Public Sub New(ByVal carNumber As Integer)
    Me.carId = carNumber
    Me.testThread.IsBackground = False ' <--This will cause threads to be 'Foreground'
    Me.testThread.Start()
End Sub