LambdaOverhead

PerfTest.cs

using System;
using NUnit.Framework;
using Unity.PerformanceTesting;

[TestFixture]
public class PerfTest
{
    [Test, Performance]
    public void LambdaOverhead()
    {
        var iterations = 1_000_000;
        Measure.Method(() =>
        {
            for (var i = 0; i < iterations; i++)
            {
                using (new SomeScope())
                {
                }
            }
        }).SampleGroup("Baseline").Run();
        
        Measure.Method(() =>
        {
            for (var i = 0; i < iterations; i++)
            {
                using (new SomeScope())
                {
                    DoStuff();
                }
            }
        }).SampleGroup("No Lambda").Run();

        Measure.Method(() =>
        {
            for (var i = 0; i < iterations; i++)
            {
                DoInScope(() => DoStuff());
            }
        }).SampleGroup("Lambda").Run();

        Measure.Method(() =>
        {
            for (var i = 0; i < iterations; i++)
            {
                DoInScope(() => DoStuffInstance());
            }
        }).SampleGroup("Closure Shared").Run();

        Measure.Method(() =>
        {
            for (var i = 0; i < iterations; i++)
            {
                DoInScope(() => DoStuff(i));
            }
        }).SampleGroup("Closure Unique").Run();
    }

    static void DoInScope(Action action)
    {
        using (new SomeScope())
        {
            DoStuff();
        }
    }

    static void DoStuff()
    {
    }

    static void DoStuff(int i)
    {
    }

    void DoStuffInstance()
    {
    }

    struct SomeScope : IDisposable
    {
        public void Dispose()
        {
        }
    }
}