How to automatically remove threads from the list of threads in c#

Question

As it is clear from the title
I want remove automatically threads from threads list when thread jobs done.
like:

Thread thr;
if(thr.done)
{
    threadlist.remove(thr);
}

Answer 1

you can check if the thread is finished with IsAlive and call this function in a timer:

var _timer = new Timer();
_timer.Interval = 30*1000; // specify interval time as you want
_timer.Tick += new EventHandler(timer_Tick);

void timer_Tick(object sender, EventArgs e)
{
   foreach (var thr in threadList)
   {
       if (!thr.IsAlive)
       {
            threadlist.Remove(thr);
       }
   }
}
_timer.Start();

A better solution is to use a try-finally block in thread to determine when it is finished processing. see this example:

private static int lastThreadID=0;  //We assign an ID to each thread
protected static object _lock = new object();
var thread = new Thread((tID) =>
{
    try
    {
       work();
    }
    finally
    {
       removeThread((int)tID );
    }
});
lock (_lock)
{
    threadlist.Add(Tuple.Create(++lastThreadID, thread));
}

thread.Start(lastThreadID);

Action work = () =>
{
   for (int i = 0; i < 20; i++)
       Thread.Sleep(1000);
};


private static void removeThread(int tID)
{
   lock (_lock)
    {
      threadlist.RemoveAll((x) => x.Item1 == tID);
    }
}