ThreadPoolGuardian, kills of zombie processes that run for too long.

ThreadPoolguardian.cs

public static class ThreadPoolGuardian
{
    private static readonly BlockingCollection<Guard> guards = new BlockingCollection<Guard>();

    public static void Queue(Action action)
    {
        Action wrapper = () =>
        {
            var guard = new Guard
            {
                IsDone = false,
                Thread = Thread.CurrentThread,
                Timeout = DateTime.Now.AddSeconds(5),
            };
            Guard(guard);
            action();
            guard.IsDone = true;
        };

        ThreadPool.UnsafeQueueUserWorkItem(_ => wrapper(), null);
    }

    static ThreadPoolGuardian()
    {
        var t = new Thread(() =>
        {
            foreach(var guard in guards.GetConsumingEnumerable())
            {
                if (guard.IsDone)
                    continue;

                if (guard.Timeout >= DateTime.Now)
                {
                    TimeSpan delay =  guard.Timeout - DateTime.Now;
                    if (delay.Milliseconds > 0) //could possibly occur
                        Thread.Sleep(delay);
                }

                if (!guard.IsDone)
                {
                    Console.WriteLine("Killing thread " + guard.Thread.GetHashCode());
                    guard.Thread.Abort();
                }
            }
            Console.WriteLine("exit");
        })
        {
            IsBackground = true
        };
        t.Start();
    }

    internal static void Guard(Guard guard)
    {
        guards.Add(guard);
    }
}

public class Guard
{
    public volatile bool IsDone;
    public Thread Thread;
    public DateTime Timeout;
}