//引入命名空间
using System;
using System.Threading;

public sealed class App 
{
    // Define an array with two AutoResetEvent WaitHandles.
    static WaitHandle[] waitHandles = new WaitHandle[] 
    {
        new AutoResetEvent(false),
        new AutoResetEvent(false)
    };

    // Define a random number generator for testing.
    static Random r = new Random();

    static void Main() 
    {
        // Queue up two tasks on two different threads; 
        // wait until all tasks are completed.
        DateTime dt = DateTime.Now;
        Console.WriteLine("Main thread is waiting for BOTH tasks to complete.");
        ThreadPool.QueueUserWorkItem(new WaitCallback(DoTask), waitHandles[0]);
        ThreadPool.QueueUserWorkItem(new WaitCallback(DoTask), waitHandles[1]);
        WaitHandle.WaitAll(waitHandles);
        // The time shown below should match the longest task.
        Console.WriteLine("Both tasks are completed (time waited={0})", 
            (DateTime.Now - dt).TotalMilliseconds);

        // Queue up two tasks on two different threads; 
        // wait until any tasks are completed.
        dt = DateTime.Now;
        Console.WriteLine();
        Console.WriteLine("The main thread is waiting for either task to complete.");
        ThreadPool.QueueUserWorkItem(new WaitCallback(DoTask), waitHandles[0]);
        ThreadPool.QueueUserWorkItem(new WaitCallback(DoTask), waitHandles[1]);
        int index = WaitHandle.WaitAny(waitHandles);
        // The time shown below should match the shortest task.
        Console.WriteLine("Task {0} finished first (time waited={1}).",
            index + 1, (DateTime.Now - dt).TotalMilliseconds);
    }

    static void DoTask(Object state) 
    {
        AutoResetEvent are = (AutoResetEvent) state;
        int time = 1000 * r.Next(2, 10);
        Console.WriteLine("Performing a task for {0} milliseconds.", time);
        Thread.Sleep(time);
        are.Set();
    }
}

//引入命名空间
using System;
using System.Threading;

class ThreadSleeper
{
    AutoResetEvent napDone = new AutoResetEvent(false);
    
    public void Sleep()
    {
        Thread.Sleep(1000);
        napDone.Set();
    }
    
    public static WaitHandle GetWaitHandle()
    {
        ThreadSleeper ts = new ThreadSleeper();
        Thread thread = new Thread(new ThreadStart(ts.Sleep));
        thread.Start();
        return(ts.napDone);
    }
}

class MainClass
{
    public static void Main()
    {
        WaitHandle[] waits = new WaitHandle[2];
        waits[0] = ThreadSleeper.GetWaitHandle();
        waits[1] = ThreadSleeper.GetWaitHandle();
        
        Console.WriteLine("Waiting for threads to finish");
        WaitHandle.WaitAll(waits);
        Console.WriteLine("Threads finished");
    }
}