Background Threads in C#

Question

I am new to C#.I learnt that normally all threads are foreground until unless you explicitly specify it as "background" thread using IsBackGround= true .

Some doubts popped in to my mind.

1) What is the advantage of keeping a thread as background thread?

2) When executing the folowing code :

    static void Main(string[] args)
    {
        Thread worker = new Thread(SayHello);
        worker.IsBackground = true;
        worker.Start();
        Console.WriteLine("Hello From Main");
    }

    static void SayHello()
    {
        Console.WriteLine("Hello World");
        Console.ReadKey(true);
    } 

i need to use worker.Join() to keep the main thread to wait as the program terminates immediately. Apart from Join() could i use other techniques to keep the main thread wait ?

Answer 1

1) What is the advantage of keeping a thread as background thread?

The Advantage is that a Background Thread doesn't stop the Program from terminating. In a large Application it could be a bit hard to deactivate all threads if you want to quit the Application.

Apart from Join() could i use other techniques to keep the main thread wait?

If yo want to make the Main program wait why do you make the thread a background thread in the first place then??? Besides of Join() you could use a EventWaitHandle or Monitor to make the main method wait.

Answer 2

All it means is whether this thread will keep the process alive. If all the threads in your process are marked background then .Net will shut down your process and force it to exit.

In answer to your question, yes you have to join as the thread which is in the background will not keep it alive, thus when the startup thread leaves Main() then it will allow the application to exit.