#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.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading.Tasks;

namespace Grpc.Core.Utils
{
    /// <summary>
    /// Utility methods to run microbenchmarks.
    /// </summary>
    public static class BenchmarkUtil
    {
        /// <summary>
        /// Runs a simple benchmark preceded by warmup phase.
        /// </summary>
        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();
            }

            logger.Info("Benchmark iterations: {0}", benchmarkIterations);
            var stopwatch = new Stopwatch();
            stopwatch.Start();
            for (int i = 0; i < benchmarkIterations; i++)
            {
                action();
            }
            stopwatch.Stop();
            logger.Info("Elapsed time: {0}ms", stopwatch.ElapsedMilliseconds);
            logger.Info("Ops per second: {0}", (int)((double)benchmarkIterations  * 1000 / stopwatch.ElapsedMilliseconds));
        }
    }
}
