Split address passed to AddListeningPort into host and port

src/csharp/Grpc.Core.Tests/ClientServerTest.cs

@@ -84,7 +84,7 @@ namespace Grpc.Core.Tests
         {
             server = new Server();
             server.AddServiceDefinition(ServiceDefinition);
-            int port = server.AddListeningPort(Host + ":0");
+            int port = server.AddListeningPort(Host, Server.PickUnusedPort);
             server.Start();
             channel = new Channel(Host + ":" + port);
         }

src/csharp/Grpc.Core.Tests/ServerTest.cs

@@ -47,7 +47,7 @@ namespace Grpc.Core.Tests
             GrpcEnvironment.Initialize();
 
             Server server = new Server();
-            server.AddListeningPort("localhost:0");
+            server.AddListeningPort("localhost", Server.PickUnusedPort);
             server.Start();
             server.ShutdownAsync().Wait();
 

src/csharp/Grpc.Core/Server.cs

@@ -47,6 +47,11 @@ namespace Grpc.Core
     /// </summary>
     public class Server
     {
+        /// <summary>
+        /// Pass this value as port to have the server choose an unused listening port for you.
+        /// </summary>
+        public const int PickUnusedPort = 0;
+
         // TODO(jtattermusch) : make sure the delegate doesn't get garbage collected while
         // native callbacks are in the completion queue.
         readonly ServerShutdownCallbackDelegate serverShutdownHandler;
@@ -89,29 +94,25 @@ namespace Grpc.Core
         /// Add a non-secure port on which server should listen.
         /// Only call this before Start().
         /// </summary>
-        public int AddListeningPort(string addr)
+        /// <returns>The port on which server will be listening.</returns>
+        /// <param name="host">the host</param>
+        /// <param name="port">the port. If zero, an unused port is chosen automatically.</param>
+        public int AddListeningPort(string host, int port)
         {
-            lock (myLock)
-            {
-                Preconditions.CheckState(!startRequested);
-                return handle.AddListeningPort(addr);
-            }
+            return AddListeningPortInternal(host, port, null);
         }
 
         /// <summary>
-        /// Add a secure port on which server should listen.
+        /// Add a non-secure port on which server should listen.
         /// Only call this before Start().
         /// </summary>
-        public int AddListeningPort(string addr, ServerCredentials credentials)
+        /// <returns>The port on which server will be listening.</returns>
+        /// <param name="host">the host</param>
+        /// <param name="port">the port. If zero, , an unused port is chosen automatically.</param>
+        public int AddListeningPort(string host, int port, ServerCredentials credentials)
         {
-            lock (myLock)
-            {
-                Preconditions.CheckState(!startRequested);
-                using (var nativeCredentials = credentials.ToNativeCredentials())
-                {
-                    return handle.AddListeningPort(addr, nativeCredentials);
-                }
-            }
+            Preconditions.CheckNotNull(credentials);
+            return AddListeningPortInternal(host, port, credentials);
         }
 
         /// <summary>
@@ -164,6 +165,26 @@ namespace Grpc.Core
             handle.Dispose();
         }
 
+        private int AddListeningPortInternal(string host, int port, ServerCredentials credentials)
+        {
+            lock (myLock)
+            {
+                Preconditions.CheckState(!startRequested);    
+                var address = string.Format("{0}:{1}", host, port);
+                if (credentials != null)
+                {
+                    using (var nativeCredentials = credentials.ToNativeCredentials())
+                    {
+                        return handle.AddListeningPort(address, nativeCredentials);
+                    }
+                }
+                else
+                {
+                    return handle.AddListeningPort(address);    
+                }
+            }
+        }
+
         /// <summary>
         /// Allows one new RPC call to be received by server.
         /// </summary>

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

@@ -46,7 +46,7 @@ namespace math
 
             Server server = new Server();
             server.AddServiceDefinition(MathGrpc.BindService(new MathServiceImpl()));
-            int port = server.AddListeningPort(host + ":23456");
+            int port = server.AddListeningPort(host, 23456);
             server.Start();
 
             Console.WriteLine("MathServer listening on port " + port);

src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs

@@ -59,7 +59,7 @@ namespace math.Tests
 
             server = new Server();
             server.AddServiceDefinition(MathGrpc.BindService(new MathServiceImpl()));
-            int port = server.AddListeningPort(host + ":0");
+            int port = server.AddListeningPort(host, Server.PickUnusedPort);
             server.Start();
             channel = new Channel(host + ":" + port);
 

src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs

@@ -59,7 +59,7 @@ namespace Grpc.IntegrationTesting
 
             server = new Server();
             server.AddServiceDefinition(TestServiceGrpc.BindService(new TestServiceImpl()));
-            int port = server.AddListeningPort(host + ":0", TestCredentials.CreateTestServerCredentials());
+            int port = server.AddListeningPort(host, Server.PickUnusedPort, TestCredentials.CreateTestServerCredentials());
             server.Start();
 
             var channelArgs = ChannelArgs.CreateBuilder()

src/csharp/Grpc.IntegrationTesting/InteropServer.cs

@@ -93,16 +93,17 @@ namespace Grpc.IntegrationTesting
             var server = new Server();
             server.AddServiceDefinition(TestServiceGrpc.BindService(new TestServiceImpl()));
 
-            string addr = "0.0.0.0:" + options.port;
+            string host = "0.0.0.0";
+            int port = options.port.Value;
             if (options.useTls)
             {
-                server.AddListeningPort(addr, TestCredentials.CreateTestServerCredentials());
+                server.AddListeningPort(host, port, TestCredentials.CreateTestServerCredentials());
             }
             else
             {
-                server.AddListeningPort(addr);
+                server.AddListeningPort(host, options.port.Value);
             }
-            Console.WriteLine("Running server on " + addr);
+            Console.WriteLine("Running server on " + string.Format("{0}:{1}", host, port));
             server.Start();
 
             server.ShutdownTask.Wait();