Task synchronization with ManualResetEvent

manualresetevent.cs

class Program
{
    static void Main(string[] args)
    {
        using var signal = new ManualResetEvent(false);
        var t1 = Task.Run(() =>
        {
            Runner(signal, 1);
        });

        var t2 = Task.Run(() =>
        {
            Runner(signal, 2);
        });
        Task.WhenAll(t1, t2).ContinueWith(task => signal.Reset());
        Thread.Sleep(1000); // operation
        signal.Set();
        Console.ReadLine();
    }

    static void Runner(ManualResetEvent signal, int id)
    {
        Console.WriteLine($"Runner [{id}] is ready");
        signal.WaitOne();
        Console.WriteLine($"Runner [{id}] start!");
        Thread.Sleep(1000); // operation
        Console.WriteLine($"Runner [{id}] finished!");
    }
}