using System;

using System.Collections.Concurrent;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

​

namespace ThreadPumpMsg

{

    public class Program

    {

        private sealed class SingleThreadSynchronizationContext : SynchronizationContext

        {

            private readonly BlockingCollection<KeyValuePair<SendOrPostCallback, object>> m_queue =

                new BlockingCollection<KeyValuePair<SendOrPostCallback, object>>();

​

            public override void Post(SendOrPostCallback d, object state)

            {

                m_queue.Add(new KeyValuePair<SendOrPostCallback, object>(d, state));

            }

​

            public void RunOnCurrentThread()

            {

                KeyValuePair<SendOrPostCallback, object> workItem;

​

                while (m_queue.TryTake(out workItem, Timeout.Infinite))

                {

                    workItem.Key(workItem.Value);

                }

            }

​

            public void Complete()

            {

                m_queue.CompleteAdding();

            }

        }

​

        public static void Run(Func<Task> func)

        {

            var prevCtx = SynchronizationContext.Current;

​

            try

            {

                var syncCtx = new SingleThreadSynchronizationContext();

​

                SynchronizationContext.SetSynchronizationContext(syncCtx);

​

                var t = func();

​

                t.ContinueWith(

​

                    delegate { syncCtx.Complete(); }, TaskScheduler.Default);

​

                syncCtx.RunOnCurrentThread();

​

                t.GetAwaiter().GetResult();

​

            }

            finally

            {

                SynchronizationContext.SetSynchronizationContext(prevCtx);

            }

        }

​

        public static void Main()

        {

            // exécute la boucle dans plusieurs threads

            //DemoAsync().Wait();

​

            // exécute la boucle dans le thread principal

            Run(async delegate

            {

                await DemoAsync();

            });

        }

​

        static async Task DemoAsync()

        {

            var d = new Dictionary<int, int>();

​

            for (int i = 0; i < 10000; i++)

            {

                int id = Thread.CurrentThread.ManagedThreadId;

                int count;

​

                d[id] = d.TryGetValue(id, out count) ? count + 1 : 1;

​

                await Task.Yield();

            }

​

            foreach (var pair in d)

                Console.WriteLine(pair);

        }

    }

}

​