c# – 异步等待和并行

我对async / await如何作为并行工作感到困惑所以我在这里制作了一个测试代码：
我尝试用列表模拟发送6个任务.
每个任务都将执行3个其他子任务.

你可以复制/粘贴测试

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

namespace ConsoleApplication1
{
    class Program
    {
         static void Main(string[] args)
        {
            //job simulation 
            Func<int,string,Tuple<int,string>> tc = Tuple.Create;
            var input = new List<Tuple<int,string>>{
                  tc( 6000,"task 1" ),tc( 5000,"task 2" ),tc( 1000,"task 3" ),"task 4" ),"task 5" ),"task 6" )
            };

            List<Tuple<int,string>> JobsList = new List<Tuple<int,string>>(input);

            //paralelism atempt
            List<Task> TaskLauncher = new List<Task>();

            Parallel.ForEach<Tuple<int,string>>(JobsList,item =>  Jobdispatcher(item.Item1,item.Item2));

            Console.ReadLine();
        }
        public static async Task Jobdispatcher(int time,string query)
        {
          List<Task> TList = new List<Task>();
          Task<string> T1 = SubTask1(time,query);
          Task<string> T2 = SubTask2(time,query);
          Task<string> T3 = SubTask3(time,query);
          TList.Add(T1);
          TList.Add(T2);
          TList.Add(T3);
          Console.WriteLine("{0} Launched ",query);

          await Task.WhenAll(TList.ToArray());


          Console.WriteLine(T1.Result);
          Console.WriteLine(T2.Result);
          Console.WriteLine(T3.Result);

        }


        public static async Task<string> SubTask1(int time,string query)
        {
            //somework
            Thread.Sleep(time);
            return query + "Finshed SubTask1";
        }
        public static async Task<string> SubTask2(int time,string query)
        {
            //somework
            Thread.Sleep(time);
            return query + "Finshed SubTask2";
        }
        public static async Task<string> SubTask3(int time,string query)
         {
             //somework
             Thread.Sleep(time);
             return query + "Finshed SubTask3";
         }


    }
}

理想情况下,我应该阅读：

task 1 launched
task 2 launched
task 3 launched
task 4 launched
task 5 launched
task 6 launched

然后在这一点上所有任务都运行6 * 3 = 18个线程同时运行
但它不是发生在这里的东西似乎执行同步.

结果如下：

什么是编写可以启动任务和子任务作为18并行线程与异步/等待的东西的方法是什么？

解决方法

试试这个示例代码.请注意,它在大约6秒内完成,这表明所有任务都是异步运行的：

using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main()
        {
            // ThreadPool throttling may cause the speed with which
            // the threads are launched to be throttled.
            // You can avoid that by uncommenting the following line,// but that is considered bad form:

            // ThreadPool.SetMinThreads(20,20);

            var sw = Stopwatch.StartNew();
            Console.WriteLine("Waiting for all tasks to complete");

            RunWorkers().Wait();

            Console.WriteLine("All tasks completed in " + sw.Elapsed);
        }

        public static async Task RunWorkers()
        {
            await Task.WhenAll(
                Jobdispatcher(6000,"task 1"),Jobdispatcher(5000,"task 2"),Jobdispatcher(4000,"task 3"),Jobdispatcher(3000,"task 4"),Jobdispatcher(2000,"task 5"),Jobdispatcher(1000,"task 6")
            );
        }

        public static async Task Jobdispatcher(int time,string query)
        {
            var results = await Task.WhenAll(
                worker(time,query + ": Subtask 1"),worker(time,query + ": Subtask 2"),query + ": Subtask 3")
            );

            Console.WriteLine(string.Join("\n",results));
        }

        static async Task<string> worker(int time,string query)
        {
            return await Task.Run(() =>
            {
                Console.WriteLine("Starting worker " + query);
                Thread.Sleep(time);
                Console.WriteLine("Completed worker " + query);
                return query + ": " + time + ",thread id: " + Thread.CurrentThread.ManagedThreadId;
            });
        }
    }
}

以下是在RunWorkers()中使用一系列任务的方法：

public static async Task RunWorkers()
{
    Task[] tasks = new Task[6];

    for (int i = 0; i < 6; ++i)
        tasks[i] = Jobdispatcher(1000 + i*1000,"task " + i);

    await Task.WhenAll(tasks);
}