TaskCreationOptions.AttachedToParent 阻塞执行

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace AttachedToParent
{
    class Program
    {
        static void Main(string[] args)
        {
            #region 异步
            Task task = new Task(() =>
            {
                Task task1 = new Task(() =>
                {
                    Thread.Sleep(100);
                    Console.WriteLine("task1");
                });

                Task task2 = new Task(() =>
                {
                    Thread.Sleep(10);
                    Console.WriteLine("task2");
                });

                task1.Start();

                task2.Start();
            });

            task.Start();
            // 这个主线程会继续执行下面的console.write
            task.Wait();  //task.WaitAll(task1,task2);

            Console.WriteLine("我是主线程！！！！");
            Console.Read();
            #endregion



            #region 同步执行
            //AttachedToParent的意思就是将task加入主线程的task中
            //如果不添加，那么就是将task单独启动，并不与主线程关联
            task = new Task(() =>
            {
                Task task1 = new Task(() =>
                {
                    Thread.Sleep(100);
                    Console.WriteLine("task1");
                }, TaskCreationOptions.AttachedToParent);

                Task task2 = new Task(() =>
                {
                    Thread.Sleep(10);
                    Console.WriteLine("task2");
                }, TaskCreationOptions.AttachedToParent);

                task1.Start();

                task2.Start();
            });

            task.Start();
            //等待主线程的task中的所有线程执行结束，才执行wait之后的console.write
            task.Wait();  //task.WaitAll(task1,task2);

            Console.WriteLine("我是主线程！！！！");

            Console.Read();
            #endregion

        }
    }
}

TaskCreationOptions.DenyChildAttach 禁止阻塞

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace DenyChildAttach
{
    class Program
    {
        static void Main(string[] args)
        {
            Task task = new Task(() =>
            {
                Task task1 = new Task(() =>
                {
                    Thread.Sleep(100);
                    Console.WriteLine("task1");
                }, TaskCreationOptions.AttachedToParent);

                Task task2 = new Task(() =>
                {
                    Thread.Sleep(10);
                    Console.WriteLine("task2");
                }, TaskCreationOptions.AttachedToParent);

                task1.Start();

                task2.Start();
            }, TaskCreationOptions.DenyChildAttach);

            task.Start();

            task.Wait();  //task.WaitAll(task1,task2);

            Console.WriteLine("我是主线程！！！！");

            Console.Read();
        }

    }
}