using System;

using System.Threading.Tasks;

using NLog; 

using NLog.Targets.Wrappers;

​

public class Program

{

    static Logger Log;

    public static void Main()

    {

        var target = new NLog.Targets.ColoredConsoleTarget();

        target.Layout= NLog.Layouts.Layout.FromString("${date:format=HH\\:mm\\:ss} ${pad:padCharacter= :padding=10:fixedLength=True:inner=${logger}} ${mdlc:item=ProcessDescriptorId}   ${threadid}   ${message} ${exception:format=tostring} ${exception:format=stacktrace}");

        var wrapper = new AsyncTargetWrapper();

        wrapper.WrappedTarget = target;

        wrapper.QueueLimit = 5000;

        wrapper.OverflowAction = AsyncTargetWrapperOverflowAction.Discard;

        NLog.Config.SimpleConfigurator.ConfigureForTargetLogging(wrapper, LogLevel.Debug);

        Log = LogManager.GetLogger("MainThread");

        var o = OuterClass.Instance;

        Log.Debug("Finished");

        System.Threading.Thread.Sleep(1000);

    }

    public class OuterClass

    {   

        static Logger Log = LogManager.GetLogger("OuterClass");

​

        private static InnerClass _innerClass;

        public static OuterClass Instance { get; private set; }

​

        private OuterClass()

        {

            Log.Debug("Constructor called");

            _innerClass = new InnerClass();

        }

​

        static OuterClass()

        {

            Instance = new OuterClass();

        }

​

        public class InnerClass

        {

            // using it's own logger, it will not dead lock

            static Logger Log = LogManager.GetLogger("InnerClass");

​

            private String _data;

            public InnerClass()

            {

                LoadOrUpdateDataAsync().Wait(); // will make the second Log.Debug call dead lock

                //_ = LoadOrUpdateDataAsync(); // will work

            }

​

            public async Task LoadOrUpdateDataAsync()

            {

                Log.Debug("This works");

​

                _data = await DataClass.GetDataAsync("https://google.com");

​

                Log.Debug("If you see this, it did not block"); // this line blocks

            }

        }

    }

​

    public static class DataClass

    {

        static Logger Log = LogManager.GetLogger("DataClass");

        public static async Task<string> GetDataAsync(string uri)

        {

            // just example code, HttpClient should not be in a using block

            using (var client = new System.Net.Http.HttpClient())

            {

                var data = await client.GetStringAsync(uri);

                Log.Debug("Data loaded from {0}", uri);

                return data;

            }

        }

    }

}