I have an application I am writing that is using multiple threads to pull
down files from a web service. I want a thread to run for each file needed to
pull down. The code I have written works wonderfully. However, when I add in
the ability to control the number of threads running at any point in time to
be only 3 and then when one has finished another is started. So, if there are
15 files only 3 are being downloaded at the same time, when the first one has
finished another thread is started to get the next file. I then run into a
problem I am grappling with and need some help. The culprit is the while loop
in the code below:

            for(int i=0; i<files.Length;i++)
            {
                while(threadsStarted >= maxThreads)
                {
                    Thread.Sleep(50);
                    //hang tight for available thread to start
                }

                Interlocked.Increment(ref threadsStarted);

               
                WorkerClass wc = new WorkerClass( this, showProgress, new object[] {
imsgs,files[i], decrementThreads } );
                Thread t = new Thread( new ThreadStart(wc.RunProcess));
                t.IsBackground = true; //make them a daemon - prevent thread callback
issues
                t.Start();
                EnableButton ( false );
            }

When the threadsStarted reaches 3 it equals the maxThreads (which is set to
3 in code before this) then it is as if my threads stop running. I set a
break point in code that runs in the method the thread executes and it stops
at the point as long as threadsStarted variable is less than 3 but after that
it does not. So it seems like the while loop is suspending everything.

Any ideas how to correct this? I know I must be doing something wrong - I
just don't know what.

-Demetri