make main methods async

src/csharp/Grpc.Examples.MathClient/MathClient.cs

@@ -16,29 +16,30 @@
 using System;
 using System.Runtime.InteropServices;
 using System.Threading;
+using System.Threading.Tasks;
 using Grpc.Core;
 
 namespace Math
 {
     class MathClient
     {
-        public static void Main(string[] args)
+        public static async Task Main(string[] args)
         {
             var channel = new Channel("127.0.0.1", 23456, ChannelCredentials.Insecure);
             Math.MathClient client = new Math.MathClient(channel);
             MathExamples.DivExample(client);
 
-            MathExamples.DivAsyncExample(client).Wait();
+            await MathExamples.DivAsyncExample(client);
 
-            MathExamples.FibExample(client).Wait();
+            await MathExamples.FibExample(client);
 
-            MathExamples.SumExample(client).Wait();
+            await MathExamples.SumExample(client);
 
-            MathExamples.DivManyExample(client).Wait();
+            await MathExamples.DivManyExample(client);
 
-            MathExamples.DependendRequestsExample(client).Wait();
+            await MathExamples.DependendRequestsExample(client);
 
-            channel.ShutdownAsync().Wait();
+            await channel.ShutdownAsync();
         }
     }
 }

src/csharp/Grpc.Examples.MathServer/MathServer.cs

@@ -17,6 +17,7 @@
 using System;
 using System.Runtime.InteropServices;
 using System.Threading;
+using System.Threading.Tasks;
 using Grpc.Core;
 
 namespace Math
@@ -26,7 +27,7 @@ namespace Math
         const string Host = "0.0.0.0";
         const int Port = 23456;
 
-        public static void Main(string[] args)
+        public static async Task Main(string[] args)
         {
             Server server = new Server
             {
@@ -40,7 +41,7 @@ namespace Math
             Console.WriteLine("Press any key to stop the server...");
             Console.ReadKey();
 
-            server.ShutdownAsync().Wait();
+            await server.ShutdownAsync();
         }
     }
 }