Why 3 threads for a basic single threaded c# console app?

Question

I created a console app in c# with a single console.readline statement. Running this app within visual studio and stepping into the debugger shows 7 thread in the thread window (6 worker threads, one is .NET SystemEvents and the other is vshost.RunParkingWindow and the main thread). When I run the app outside visual studio I see a total of 3 threads in windows task manager. Why so many? I would expect 1 thread? What are the others being spawned for?

Thanks

Answer 1

They must be sleeping. Unfortunately sometimes Microsoft does not always practice what it preaches. If you don't trust me, check the number of threads used by your visual studio or the Microsoft outlook by enabling the threads column in your process explorer window of Windows Task manager.

Answer 2

If you're running a .NET application, I believe you always get a thread (mostly sleeping) for the JIT as well as the GC thread, in addition to your main thread.

Answer 3

Don't forget that finalizer thread !

Answer 4

There is a way to move SystemEvents notifier into your thread:

public static class ThreadingHelper_NativeMethods
{
   [DllImport("user32.dll")]
   public static extern bool IsGUIThread(bool bConvert);
}


     // This code forces initialization of .NET BroadcastEventWindow to the UI thread.
     // http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/fb267827-1765-4bd9-ae2f-0abbd5a2ae22
     if (ThreadingHelper_NativeMethods.IsGUIThread(false))
     {
        Microsoft.Win32.SystemEvents.InvokeOnEventsThread(new MethodInvoker(delegate()
        {
           int x = 0;
        }));
     }