using System;

using System.Threading;

using System.Threading.Tasks;

​

namespace ConsoleTest

{

    class Program

    {

        static AsyncLocal<string> asyncLocal = new();

​

        static async Task Main()

        {

            asyncLocal.Value = "heh";

​

            Console.WriteLine($"Main() before: {asyncLocal.Value}");

            await Run(false, false);

            Console.WriteLine($"Main() after: {asyncLocal.Value}");

​

            Console.WriteLine();

​

            asyncLocal.Value = "heh";

​

            Console.WriteLine($"Main() before suppressed: {asyncLocal.Value}");

            await Run(false, true);

            Console.WriteLine($"Main() after suppressed: {asyncLocal.Value}");

​

            Console.WriteLine();

            Console.WriteLine();

​

            asyncLocal.Value = "heh";

​

            Console.WriteLine($"Main() before sync: {asyncLocal.Value}");

            await Run(true, false);

            Console.WriteLine($"Main() after sync: {asyncLocal.Value}");

​

            Console.WriteLine();

​

            asyncLocal.Value = "heh";

​

            Console.WriteLine($"Main() before sync suppressed: {asyncLocal.Value}");

            await Run(true, true);

            Console.WriteLine($"Main() after sync suppressed: {asyncLocal.Value}");

        }

​

        static Task Run(bool synchronous, bool suppress)

        {

            if (suppress)

            {

                using (ExecutionContext.SuppressFlow())

                {

                    return run();

                }

            }

            else

            {

                return run();

            }

​

            Task run()

            {

                Console.WriteLine($"  Run() before 1, synchronous={synchronous}, suppress={suppress}: {asyncLocal.Value}");

                asyncLocal.Value = "hi";

                Console.WriteLine($"  Run() before 2, synchronous={synchronous}, suppress={suppress}: {asyncLocal.Value}");

​

                if (synchronous)

                    return TestSynchronous();

                else

                    return Test();

            }

        }

​

        static async Task Test()

        {

            await Task.Yield();

​

            var context = ExecutionContext.Capture();

​

            Console.WriteLine($"    Test() EC is null: {context is null}");

​

            if (context is not null)

                ExecutionContext.Run(context!, run, null);

            else

                run(null);

​

            return;

​

            void run(object state)

            {

                Console.WriteLine($"    Test() before: {asyncLocal.Value}");

                asyncLocal.Value = "hello";

                Console.WriteLine($"    Test() after: {asyncLocal.Value}");

            }

​

            //Console.WriteLine($"    Test() before: {asyncLocal.Value}");

            //asyncLocal.Value = "hello";

            //Console.WriteLine($"    Test() after: {asyncLocal.Value}");

        }

​

        static Task TestSynchronous()

        {

            var context = ExecutionContext.Capture();

​

            Console.WriteLine($"    TestSynchronous() EC is null: {context is null}");

​

            if (context is not null)

                ExecutionContext.Run(context!, run, null);

            else

                run(null);

​

            return Task.CompletedTask;

​

            void run(object state)

            {

                Console.WriteLine($"    TestSynchronous() before: {asyncLocal.Value}");

                asyncLocal.Value = "hello";

                Console.WriteLine($"    TestSynchronous() after: {asyncLocal.Value}");

            }

        }

    }

}

​