Added support for true synchronous unary call and added some performance tests.

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

@@ -101,15 +101,8 @@ namespace Grpc.Core.Tests
             using (Channel channel = new Channel(host + ":" + port))
             {
                 var call = new Call<string, string>(unaryEchoStringMethod, channel);
-
+                BenchmarkUtil.RunBenchmark(100, 1000,
-                var stopwatch = new Stopwatch();
+                                           () => { Calls.BlockingUnaryCall(call, "ABC", default(CancellationToken)); });
-                stopwatch.Start();
-                for (int i = 0; i < 1000; i++)
-                {
-                    Calls.BlockingUnaryCall(call, "ABC", default(CancellationToken));
-                }
-                stopwatch.Stop();
-                Console.WriteLine("Elapsed time: " + stopwatch.ElapsedMilliseconds + "ms");
             }
 
             server.ShutdownAsync().Wait();

src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj

@@ -41,6 +41,7 @@
     <Compile Include="ServerTest.cs" />
     <Compile Include="GrpcEnvironmentTest.cs" />
     <Compile Include="TimespecTest.cs" />
+    <Compile Include="PInvokeTest.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>

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

@@ -0,0 +1,139 @@
+#region Copyright notice and license
+
+// Copyright 2015, 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.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+using System.Runtime.InteropServices;
+
+namespace Grpc.Core.Tests
+{
+    public class PInvokeTest
+    {
+        int counter;
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern GRPCCallError grpcsharp_test_callback([MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern IntPtr grpcsharp_test_nop(IntPtr ptr);
+
+        [TestFixtureSetUp]
+        public void Init()
+        {
+            GrpcEnvironment.Initialize();
+        }
+
+        [TestFixtureTearDown]
+        public void Cleanup()
+        {
+            GrpcEnvironment.Shutdown();
+        }
+
+        [Test]
+        public void CompletionQueueCreateDestroyBenchmark()
+        {
+            BenchmarkUtil.RunBenchmark(
+                100000, 1000000,
+                () => {
+                    CompletionQueueSafeHandle cq = CompletionQueueSafeHandle.Create();
+                    cq.Dispose();
+                }
+            );
+        }
+
+
+        /// <summary>
+        /// Approximate results:
+        /// (mono ~80ns)
+        /// </summary>
+        [Test]
+        public void NativeCallbackBenchmark()
+        {
+            CompletionCallbackDelegate handler = Handler;
+
+            counter = 0;
+            BenchmarkUtil.RunBenchmark(
+                1000000, 10000000,
+                () => {
+                    grpcsharp_test_callback(handler);
+                }
+            );
+            Assert.AreNotEqual(0, counter);
+        }
+
+        /// <summary>
+        /// Creating a new native-to-managed callback has significant overhead
+        /// compared to using an existing one. We need to be aware of this.
+        /// (~50us on mono)
+        /// </summary>
+        [Test]
+        public void NewNativeCallbackBenchmark()
+        {
+            counter = 0;
+            BenchmarkUtil.RunBenchmark(
+                10000, 10000,
+                () => {
+                grpcsharp_test_callback(new CompletionCallbackDelegate(Handler));
+            }
+            );
+            Assert.AreNotEqual(0, counter);
+        }
+
+        /// <summary>
+        /// Tests overhead of a simple PInvoke call.
+        /// </summary>
+        [Test]
+        public void NopPInvokeBenchmark()
+        {
+            CompletionCallbackDelegate handler = Handler;
+
+            BenchmarkUtil.RunBenchmark(
+                1000000, 100000000,
+                () => {
+                    grpcsharp_test_nop(IntPtr.Zero);
+                }
+            );
+        }
+
+        private void Handler(GRPCOpError op, IntPtr ptr) {
+            counter ++;
+        }
+    }
+}
+

src/csharp/Grpc.Core/Calls.cs

@@ -47,19 +47,22 @@ namespace Grpc.Core
     {
         public static TResponse BlockingUnaryCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, CancellationToken token)
         {
+            var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
+            return asyncCall.UnaryCall(call.Channel, call.MethodName, req);
+
             //TODO: implement this in real synchronous style.
-            try {
+//            try {
-                return AsyncUnaryCall(call, req, token).Result;
+//                return AsyncUnaryCall(call, req, token).Result;
-            } catch(AggregateException ae) {
+//            } catch(AggregateException ae) {
-                foreach (var e in ae.InnerExceptions)
+//                foreach (var e in ae.InnerExceptions)
-                {
+//                {
-                    if (e is RpcException)
+//                    if (e is RpcException)
-                    {
+//                    {
-                        throw e;
+//                        throw e;
-                    }
+//                    }
-                }
+//                }
-                throw;
+//                throw;
-            }
+//            }
         }
 
         public static async Task<TResponse> AsyncUnaryCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, CancellationToken token)

src/csharp/Grpc.Core/Grpc.Core.csproj

@@ -62,6 +62,7 @@
     <Compile Include="Internal\ClientStreamingInputObserver.cs" />
     <Compile Include="Internal\ServerStreamingOutputObserver.cs" />
     <Compile Include="Internal\BatchContextSafeHandleNotOwned.cs" />
+    <Compile Include="Utils\BenchmarkUtil.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>

src/csharp/Grpc.Core/Internal/AsyncCall.cs

@@ -112,6 +112,31 @@ namespace Grpc.Core.Internal
             InitializeInternal(call, true);
         }
 
+        public TRead UnaryCall(Channel channel, String methodName, TWrite msg)
+        {
+            using(CompletionQueueSafeHandle cq = CompletionQueueSafeHandle.Create())
+            {
+                // TODO: handle serialization error...
+                byte[] payload = serializer(msg);
+
+                unaryResponseTcs = new TaskCompletionSource<TRead>();
+
+                lock (myLock)
+                {
+                    Initialize(channel, cq, methodName);
+                    started = true;
+                    halfcloseRequested = true;
+                    readingDone = true;
+                }
+                call.BlockingUnary(cq, payload, unaryResponseHandler);
+
+                // task should be finished once BlockingUnary returns.
+                return unaryResponseTcs.Task.Result;
+
+                // TODO: unwrap aggregate exception...
+            }
+        }
+
         public Task<TRead> UnaryCallAsync(TWrite msg)
         {
             lock (myLock)

src/csharp/Grpc.Core/Internal/CallSafeHandle.cs

@@ -62,6 +62,11 @@ namespace Grpc.Core.Internal
                                                                         [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback,
                                                                         byte[] send_buffer, UIntPtr send_buffer_len);
 
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern void grpcsharp_call_blocking_unary(CallSafeHandle call, CompletionQueueSafeHandle dedicatedCq,
+                                                               [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback,
+                                                               byte[] send_buffer, UIntPtr send_buffer_len);
+
         [DllImport("grpc_csharp_ext.dll")]
         static extern GRPCCallError grpcsharp_call_start_client_streaming(CallSafeHandle call,
                                                                       [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
@@ -113,6 +118,11 @@ namespace Grpc.Core.Internal
             AssertCallOk(grpcsharp_call_start_unary(this, callback, payload, new UIntPtr((ulong) payload.Length)));
         }
 
+        public void BlockingUnary(CompletionQueueSafeHandle dedicatedCq, byte[] payload, CompletionCallbackDelegate callback)
+        {
+            grpcsharp_call_blocking_unary(this, dedicatedCq, callback, payload, new UIntPtr((ulong) payload.Length));
+        }
+
         public void StartClientStreaming(CompletionCallbackDelegate callback)
         {
             AssertCallOk(grpcsharp_call_start_client_streaming(this, callback));

src/csharp/Grpc.Core/Utils/BenchmarkUtil.cs

@@ -0,0 +1,68 @@
+#region Copyright notice and license
+
+// Copyright 2015, 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.Threading.Tasks;
+using System.Collections.Generic;
+using System.Collections.Concurrent;
+using System.Diagnostics;
+
+namespace Grpc.Core.Utils
+{
+    public static class BenchmarkUtil
+    {
+        /// <summary>
+        /// Runs a simple benchmark preceded by warmup phase.
+        /// </summary>
+        public static void RunBenchmark(int warmupIterations, int benchmarkIterations, Action action)
+        {
+            Console.WriteLine("Warmup iterations: " + warmupIterations);
+            for (int i = 0; i < warmupIterations; i++)
+            {
+                action();
+            }
+
+            Console.WriteLine("Benchmark iterations: " + benchmarkIterations);
+            var stopwatch = new Stopwatch();
+            stopwatch.Start();
+            for (int i = 0; i < benchmarkIterations; i++)
+            {
+                action();
+            }
+            stopwatch.Stop();
+            Console.WriteLine("Elapsed time: " + stopwatch.ElapsedMilliseconds + "ms");
+            Console.WriteLine("Ops per second: " + (int) ((double) benchmarkIterations  * 1000 / stopwatch.ElapsedMilliseconds));
+        }
+    }
+}
+

src/csharp/Grpc.IntegrationTesting/Client.cs

@@ -33,7 +33,9 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 using Google.ProtocolBuffers;
 using Grpc.Core;
 using Grpc.Core.Utils;
@@ -128,6 +130,9 @@ namespace Grpc.IntegrationTesting
                 case "empty_stream":
                     RunEmptyStream(client);
                     break;
+                case "benchmark_empty_unary":
+                    RunBenchmarkEmptyUnary(client);
+                    break;
                 default:
                     throw new ArgumentException("Unknown test case " + testCase);
             }
@@ -267,6 +272,12 @@ namespace Grpc.IntegrationTesting
             Console.WriteLine("Passed!");
         }
 
+        // This is not an official interop test, but it's useful.
+        private void RunBenchmarkEmptyUnary(TestServiceGrpc.ITestServiceClient client)
+        {
+            BenchmarkUtil.RunBenchmark(10000, 10000,
+                                       () => { client.EmptyCall(Empty.DefaultInstance);});
+        }
 
         private Payload CreateZerosPayload(int size) {
             return Payload.CreateBuilder().SetBody(ByteString.CopyFrom(new byte[size])).Build();

src/csharp/ext/grpc_csharp_ext.c

@@ -343,6 +343,18 @@ grpcsharp_call_start_unary(grpc_call *call, callback_funcptr callback,
   return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
+/* Synchronous unary call */
+GPR_EXPORT void GPR_CALLTYPE
+grpcsharp_call_blocking_unary(grpc_call *call, grpc_completion_queue *dedicated_cq, callback_funcptr callback,
+                           const char *send_buffer, size_t send_buffer_len) {
+  GPR_ASSERT(grpcsharp_call_start_unary(call, callback, send_buffer, send_buffer_len) == GRPC_CALL_OK);
+
+  /* TODO: we would like to use pluck, but we don't know the tag */
+  GPR_ASSERT(grpcsharp_completion_queue_next_with_callback(dedicated_cq) == GRPC_OP_COMPLETE);
+  grpc_completion_queue_shutdown(dedicated_cq);
+  GPR_ASSERT(grpcsharp_completion_queue_next_with_callback(dedicated_cq) == GRPC_QUEUE_SHUTDOWN);
+}
+
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
 grpcsharp_call_start_client_streaming(grpc_call *call,
                                       callback_funcptr callback) {
@@ -566,3 +578,16 @@ grpcsharp_server_request_call(grpc_server *server, grpc_completion_queue *cq,
       server, &(ctx->server_rpc_new.call), &(ctx->server_rpc_new.call_details),
       &(ctx->server_rpc_new.request_metadata), cq, ctx);
 }
+
+
+/* For testing */
+GPR_EXPORT void GPR_CALLTYPE
+grpcsharp_test_callback(callback_funcptr callback) {
+  callback(GRPC_OP_OK, NULL);
+}
+
+/* For testing */
+GPR_EXPORT void *GPR_CALLTYPE
+grpcsharp_test_nop(void *ptr) {
+  return ptr;
+}