Initial checkin of gRPC to third_party/

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

 #region Copyright notice and license
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
+
+// 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.Collections.Concurrent;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Threading.Tasks;
 
-namespace Google.Protobuf.Reflection
+namespace Grpc.Core.Utils
 {
     /// <summary>
-    /// Internal class containing utility methods when working with descriptors.
+    /// Utility methods to run microbenchmarks.
     /// </summary>
-    internal static class DescriptorUtil
+    public static class BenchmarkUtil
     {
         /// <summary>
-        /// Equivalent to Func[TInput, int, TOutput] but usable in .NET 2.0. Only used to convert
-        /// arrays.
+        /// Runs a simple benchmark preceded by warmup phase.
         /// </summary>
-        internal delegate TOutput IndexedConverter<TInput, TOutput>(TInput element, int index);
+        public static void RunBenchmark(int warmupIterations, int benchmarkIterations, Action action)
+        {
+            var logger = GrpcEnvironment.Logger;
+            
+            logger.Info("Warmup iterations: {0}", warmupIterations);
+            for (int i = 0; i < warmupIterations; i++)
+            {
+                action();
+            }
 
-        /// <summary>
-        /// Converts the given array into a read-only list, applying the specified conversion to
-        /// each input element.
-        /// </summary>
-        internal static IList<TOutput> ConvertAndMakeReadOnly<TInput, TOutput>
-            (IList<TInput> input, IndexedConverter<TInput, TOutput> converter)
-        {
-            TOutput[] array = new TOutput[input.Count];
-            for (int i = 0; i < array.Length; i++)
+            logger.Info("Benchmark iterations: {0}", benchmarkIterations);
+            var stopwatch = new Stopwatch();
+            stopwatch.Start();
+            for (int i = 0; i < benchmarkIterations; i++)
             {
-                array[i] = converter(input[i], i);
+                action();
             }
-            return new ReadOnlyCollection<TOutput>(array);
+            stopwatch.Stop();
+            logger.Info("Elapsed time: {0}ms", stopwatch.ElapsedMilliseconds);
+            logger.Info("Ops per second: {0}", (int)((double)benchmarkIterations  * 1000 / stopwatch.ElapsedMilliseconds));
         }
     }
-}
+}