add ASYNC_GENERIC_SERVER support for C#
diff --git a/src/csharp/Grpc.IntegrationTesting/ClientRunners.cs b/src/csharp/Grpc.IntegrationTesting/ClientRunners.cs
index a749f4a..e6dc232 100644
--- a/src/csharp/Grpc.IntegrationTesting/ClientRunners.cs
+++ b/src/csharp/Grpc.IntegrationTesting/ClientRunners.cs
@@ -94,7 +94,7 @@
             }
             var channel = new Channel(target, credentials, channelOptions);
 
-            return new SimpleClientRunner(channel,
+            return new ClientRunnerImpl(channel,
                 config.ClientType,
                 config.RpcType,
                 config.PayloadConfig,
@@ -102,23 +102,10 @@
         }
     }
 
-    /// <summary>
-    /// Simple protobuf client.
-    /// </summary>
-    public class SimpleClientRunner : IClientRunner
+    public class ClientRunnerImpl : IClientRunner
     {
         const double SecondsToNanos = 1e9;
 
-        readonly static Marshaller<byte[]> ByteArrayMarshaller = new Marshaller<byte[]>((b) => b, (b) => b);
-
-        readonly static Method<byte[], byte[]> StreamingCallMethod = new Method<byte[], byte[]>(
-            MethodType.DuplexStreaming,
-            "grpc.testing.BenchmarkService",
-            "StreamingCall",
-            ByteArrayMarshaller,
-            ByteArrayMarshaller
-        );
-
         readonly Channel channel;
         readonly ClientType clientType;
         readonly RpcType rpcType;
@@ -130,7 +117,7 @@
         readonly CancellationTokenSource stoppedCts;
         readonly WallClockStopwatch wallClockStopwatch = new WallClockStopwatch();
         
-        public SimpleClientRunner(Channel channel, ClientType clientType, RpcType rpcType, PayloadConfig payloadConfig, HistogramParams histogramParams)
+        public ClientRunnerImpl(Channel channel, ClientType clientType, RpcType rpcType, PayloadConfig payloadConfig, HistogramParams histogramParams)
         {
             this.channel = GrpcPreconditions.CheckNotNull(channel);
             this.clientType = clientType;
@@ -228,7 +215,7 @@
             var request = CreateByteBufferRequest();
             var stopwatch = new Stopwatch();
 
-            var callDetails = new CallInvocationDetails<byte[], byte[]>(channel, StreamingCallMethod, new CallOptions());
+            var callDetails = new CallInvocationDetails<byte[], byte[]>(channel, GenericService.StreamingCallMethod, new CallOptions());
 
             using (var call = Calls.AsyncDuplexStreamingCall(callDetails))
             {
diff --git a/src/csharp/Grpc.IntegrationTesting/GenericService.cs b/src/csharp/Grpc.IntegrationTesting/GenericService.cs
new file mode 100644
index 0000000..c612826
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/GenericService.cs
@@ -0,0 +1,71 @@
+#region Copyright notice and license
+
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using Google.Protobuf;
+using Grpc.Core;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+using Grpc.Testing;
+
+namespace Grpc.IntegrationTesting
+{
+    /// <summary>
+    /// Utility methods for defining and calling a service that doesn't use protobufs
+    /// for serialization/deserialization.
+    /// </summary>
+    public static class GenericService
+    {
+        readonly static Marshaller<byte[]> ByteArrayMarshaller = new Marshaller<byte[]>((b) => b, (b) => b);
+
+        public readonly static Method<byte[], byte[]> StreamingCallMethod = new Method<byte[], byte[]>(
+            MethodType.DuplexStreaming,
+            "grpc.testing.BenchmarkService",
+            "StreamingCall",
+            ByteArrayMarshaller,
+            ByteArrayMarshaller
+        );
+
+        public static ServerServiceDefinition BindHandler(DuplexStreamingServerMethod<byte[], byte[]> handler)
+        {
+            return ServerServiceDefinition.CreateBuilder(StreamingCallMethod.ServiceName)
+                .AddMethod(StreamingCallMethod, handler).Build();
+        }
+    }
+}
diff --git a/src/csharp/Grpc.IntegrationTesting/Grpc.IntegrationTesting.csproj b/src/csharp/Grpc.IntegrationTesting/Grpc.IntegrationTesting.csproj
index 3729913..4c04994 100644
--- a/src/csharp/Grpc.IntegrationTesting/Grpc.IntegrationTesting.csproj
+++ b/src/csharp/Grpc.IntegrationTesting/Grpc.IntegrationTesting.csproj
@@ -120,6 +120,7 @@
     <Compile Include="WorkerServiceImpl.cs" />
     <Compile Include="QpsWorker.cs" />
     <Compile Include="WallClockStopwatch.cs" />
+    <Compile Include="GenericService.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>
diff --git a/src/csharp/Grpc.IntegrationTesting/ServerRunners.cs b/src/csharp/Grpc.IntegrationTesting/ServerRunners.cs
index 516436a..c326378 100644
--- a/src/csharp/Grpc.IntegrationTesting/ServerRunners.cs
+++ b/src/csharp/Grpc.IntegrationTesting/ServerRunners.cs
@@ -61,7 +61,6 @@
         public static IServerRunner CreateStarted(ServerConfig config)
         {
             Logger.Debug("ServerConfig: {0}", config);
-            GrpcPreconditions.CheckArgument(config.ServerType == ServerType.ASYNC_SERVER, "Only ASYNC_SERVER supported for C# QpsWorker");
             var credentials = config.SecurityParams != null ? TestCredentials.CreateSslServerCredentials() : ServerCredentials.Insecure;
 
             if (config.AsyncServerThreads != 0)
@@ -77,17 +76,53 @@
                 Logger.Warning("ServerConfig.CoreList is not supported for C#. Ignoring the value");
             }
 
-            GrpcPreconditions.CheckArgument(config.PayloadConfig == null,
-                "ServerConfig.PayloadConfig shouldn't be set for BenchmarkService based server.");
+            ServerServiceDefinition service = null;
+            if (config.ServerType == ServerType.ASYNC_SERVER)
+            {
+                GrpcPreconditions.CheckArgument(config.PayloadConfig == null,
+                    "ServerConfig.PayloadConfig shouldn't be set for BenchmarkService based server.");    
+                service = BenchmarkService.BindService(new BenchmarkServiceImpl());
+            }
+            else if (config.ServerType == ServerType.ASYNC_GENERIC_SERVER)
+            {
+                var genericService = new GenericServiceImpl(config.PayloadConfig.BytebufParams.RespSize);
+                service = GenericService.BindHandler(genericService.StreamingCall);
+            }
+            else
+            {
+                throw new ArgumentException("Unsupported ServerType");
+            }
+
             var server = new Server
             {
-                Services = { BenchmarkService.BindService(new BenchmarkServiceImpl()) },
+                Services = { service },
                 Ports = { new ServerPort("[::]", config.Port, credentials) }
             };
 
             server.Start();
             return new ServerRunnerImpl(server);
         }
+
+        private class GenericServiceImpl
+        {
+            readonly byte[] response;
+
+            public GenericServiceImpl(int responseSize)
+            {
+                this.response = new byte[responseSize];
+            }
+
+            /// <summary>
+            /// Generic streaming call handler.
+            /// </summary>
+            public async Task StreamingCall(IAsyncStreamReader<byte[]> requestStream, IServerStreamWriter<byte[]> responseStream, ServerCallContext context)
+            {
+                await requestStream.ForEachAsync(async request =>
+                {
+                    await responseStream.WriteAsync(response);
+                });
+            }
+        }
     }
 
     /// <summary>
@@ -136,6 +171,5 @@
         {
             return server.ShutdownAsync();
         }
-    }
-        
+    }        
 }