C#多线程系列之线程池

public delegate void WaitCallback(object state);

    class Program
    {
        static void Main(string[] args)
        {
            ThreadPool.QueueUserWorkItem(MyAction);

            ThreadPool.QueueUserWorkItem(state =>
            {
                Console.WriteLine("任务已被执行2");
            });
            Console.ReadKey();
        }
        // state 表示要传递的参数信息，这里为 null
        private static void MyAction(Object state)
        {
            Console.WriteLine("任务已被执行1");
        }
    }

        static void Main()
        {
            Stopwatch watch = new Stopwatch();
            watch.Start();
            for (int i = 0; i < 10; i++)
                new Thread(() => { }).Start();
            watch.Stop();
            Console.WriteLine("创建 10 个线程需要花费时间(毫秒)：" + watch.ElapsedMilliseconds);
            Console.ReadKey();
        }

// 设置线程池最小工作线程数线程
public static bool SetMinThreads (int workerThreads, int completionPortThreads);

// 获取
public static void GetMinThreads (out int workerThreads, out int completionPortThreads);

// 设置线程池最大工作线程数
public static bool SetMaxThreads (int workerThreads, int completionPortThreads);

// 获取
public static void GetMaxThreads (out int workerThreads, out int completionPortThreads);

    class Program
    {
        static void Main(string[] args)
        {
            // 不断加入任务
            for (int i = 0; i < 8; i++)
                ThreadPool.QueueUserWorkItem(state =>
                {
                    Thread.Sleep(100);
                    Console.WriteLine("");
                });
            for (int i = 0; i < 8; i++)
                ThreadPool.QueueUserWorkItem(state =>
                {
                    Thread.Sleep(TimeSpan.FromSeconds(1));
                    Console.WriteLine("");
                });

            Console.WriteLine("     此计算机处理器数量：" + Environment.ProcessorCount);

            // 工作项、任务代表同一个意思
            Console.WriteLine("     当前线程池存在线程数：" + ThreadPool.ThreadCount);
            Console.WriteLine("     当前已处理的工作项数：" + ThreadPool.CompletedWorkItemCount);
            Console.WriteLine("     当前已加入处理队列的工作项数：" + ThreadPool.PendingWorkItemCount);
            int count;
            int ioCount;
            ThreadPool.GetMinThreads(out count, out ioCount);
            Console.WriteLine($"     默认最小辅助线程数：{count}，默认最小异步IO线程数：{ioCount}");

            ThreadPool.GetMaxThreads(out count, out ioCount);
            Console.WriteLine($"     默认最大辅助线程数：{count}，默认最大异步IO线程数：{ioCount}");
            Console.ReadKey();
        }
    }

     此计算机处理器数量：8
     当前线程池存在线程数：8
     当前已处理的工作项数：2
     当前已加入处理队列的工作项数：8
     默认最小辅助线程数：8，默认最小异步IO线程数：8
     默认最大辅助线程数：32767，默认最大异步IO线程数：1000

    class Program
    {
        private delegate string MyAsyncDelete(out int thisThreadId);
        static void Main(string[] args)
        {
            int threadId;
            // 不是异步调用
            MyMethodAsync(out threadId);

            // 创建自定义的委托
            MyAsyncDelete myAsync = MyMethodAsync;

            // 初始化异步的委托
            IAsyncResult result = myAsync.BeginInvoke(out threadId, null, null);

            // 当前线程等待异步完成任务，也可以去掉
            result.AsyncWaitHandle.WaitOne();
            Console.WriteLine("异步执行");

            // 检索异步执行结果
            string returnValue = myAsync.EndInvoke(out threadId, result);

            // 关闭
            result.AsyncWaitHandle.Close();

            Console.WriteLine("异步处理结果：" + returnValue);
        }
        private static string MyMethodAsync(out int threadId)
        {
            // 获取当前线程在托管线程池的唯一标识
            threadId = Thread.CurrentThread.ManagedThreadId;
            // 模拟工作请求
            Thread.Sleep(TimeSpan.FromSeconds(new Random().Next(1, 5)));
            // 返回工作完成结果
            return "喜欢我的读者可以关注笔者的博客欧~";
        }
    }

        CancellationTokenSource cts = new CancellationTokenSource();
        CancellationToken token = cts.Token;

    class Program
    {
        static void Main()
        {
            CancellationTokenSource cts = new CancellationTokenSource();

            Console.WriteLine("按下回车键，将取消任务");

            new Thread(() => { CanceTask(cts.Token); }).Start();
            new Thread(() => { CanceTask(cts.Token); }).Start();

            Console.ReadKey();
            
            // 取消执行
            cts.Cancel();
            Console.WriteLine("完成");
            Console.ReadKey();
        }

        private static void CanceTask(CancellationToken token)
        {
            Console.WriteLine("第一阶段");
            Thread.Sleep(TimeSpan.FromSeconds(1));
            if (token.IsCancellationRequested)
                return;

            Console.WriteLine("第二阶段");
            Thread.Sleep(TimeSpan.FromSeconds(1));
            if (token.IsCancellationRequested)
                return;

            Console.WriteLine("第三阶段");
            Thread.Sleep(TimeSpan.FromSeconds(1));
            if (token.IsCancellationRequested)
                return;

            Console.WriteLine("第四阶段");
            Thread.Sleep(TimeSpan.FromSeconds(1));
            if (token.IsCancellationRequested)
                return;

            Console.WriteLine("第五阶段");
            Thread.Sleep(TimeSpan.FromSeconds(1));
            if (token.IsCancellationRequested)
                return;
        }
    }

public Timer (System.Threading.TimerCallback callback, object state, uint dueTime, uint period);

    class Program
    {
        static void Main()
        {
            Timer timer = new Timer(TimeTask,null,100,1000);
            
            Console.ReadKey();
        }

        // public delegate void TimerCallback(object? state);
        private static void TimeTask(object state)
        {
            Console.WriteLine("www.whuanle.cn");
        }
    }