Performance test for CA1813 - Avoid unsealed attributes http://msdn.microsoft.com/en-us/library/ms182267(v=vs.110).aspx

gistfile1.cs

using System;
using System.Diagnostics;

namespace AttributePerformanceTest
{
    public sealed class SealedAttribute : Attribute { }
    
    public class NotSealedAttribute : Attribute { }

    public class InheritNotSealedAttribute : NotSealedAttribute { }

    public class ReInheritNotSealedAttribute : InheritNotSealedAttribute { }

    [Sealed]
    public class ClassWithSealed { }

    [NotSealed]
    public class ClassWithNotSealed { }

    [InheritNotSealed]
    public class ClassWithInherited { }

    [ReInheritNotSealed]
    public class ClassWithReInherited { }

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("*** Cold Run ***\r\n");

            Test(typeof(ClassWithSealed), typeof(SealedAttribute));
            Test(typeof(ClassWithNotSealed), typeof(NotSealedAttribute));
            Test(typeof(ClassWithInherited), typeof(NotSealedAttribute));
            Test(typeof(ClassWithReInherited), typeof(NotSealedAttribute));

            Console.WriteLine("\r\n*** Actual Test ***\r\n");

            Test(typeof(ClassWithSealed), typeof(SealedAttribute));
            Test(typeof(ClassWithNotSealed), typeof(NotSealedAttribute));
            Test(typeof(ClassWithInherited), typeof(NotSealedAttribute));
            Test(typeof(ClassWithReInherited), typeof(NotSealedAttribute));

            Console.WriteLine("\r\nDone");
            Console.ReadLine();
        }

        static void Test(Type objectType, Type attributeType, int testRepeats = 5, int count = 100000)
        {
            Console.WriteLine("Looking for {0} in {1}", attributeType.Name, objectType.Name);

            long totalElapsed = 0;

            for (int r = 0; r < testRepeats; r++)
            {
                var sw = Stopwatch.StartNew();

                for (int i = 0; i < count; i++)
                {
                    Attribute.GetCustomAttributes(objectType, attributeType);
                }

                sw.Stop();

                totalElapsed += sw.ElapsedMilliseconds;
                Console.Write("  {0} ms", sw.ElapsedMilliseconds);
            }

            Console.WriteLine("\r\nAverage: {0} ms\r\n", totalElapsed / testRepeats);
        }
    }
}

Results on my machine:

Looking for SealedAttribute in ClassWithSealed
  447 ms  449 ms  445 ms  450 ms  450 ms
Average: 448 ms

Looking for NotSealedAttribute in ClassWithNotSealed
  430 ms  424 ms  429 ms  433 ms  443 ms
Average: 431 ms

Looking for NotSealedAttribute in ClassWithInherited
  452 ms  429 ms  428 ms  435 ms  440 ms
Average: 436 ms

Looking for NotSealedAttribute in ClassWithReInherited
  440 ms  433 ms  441 ms  437 ms  433 ms
Average: 436 ms