daemon.cs

 class Program
    {
        static void Main(string[] args)
        {
            var t = new Test();
            t.Daemon();

            Console.WriteLine("end main");
            string input = Console.ReadLine();
            while (input != "x")
            {
                t.Signal();
                input = Console.ReadLine();
            }
            
        }

        
    }

    class Test
    {
        private TaskCompletionSource<string> signaler;

        private Task<string> WaitOnSignalAsync()
        {
            signaler = new TaskCompletionSource<string>();
            return signaler.Task;
        }

        public void Signal()
        {
            signaler.SetResult("signaler fired");
        }

        private Task<string> WaitOnTimeAsync()
        {
            var tcs = new TaskCompletionSource<string>();
            Task.Run(async () =>
            {
                await Task.Delay(10000);
                tcs.SetResult("timer fired");
            });

            return tcs.Task;
        }
            


        internal async Task Daemon()
        {
            while (true)
            {
                Console.WriteLine("waiting for input...");

                var result = await Task.WhenAny<string>(WaitOnTimeAsync(), WaitOnSignalAsync()).Unwrap();
                
                Console.WriteLine(result);
                Console.WriteLine("doing something...");
            }
        }
    }