[Mono-list] String comparisons slow

[Bill Blinn]

Hi,

I was trying out some tests to check performance of mono with
multithreading and benchmark Windows .NET, Windows mono and Linux
(ubuntu 9.04) mono. The results I have show that string comparisons
are much slower on mono than on .NET (8x). Am I doing something wrong?

Thanks,
bill

Here are my results:

windows .net

Running test with 2 cores and 400000 items
***** MyApp.MultiCoreTests.TestMultiThreadInt
Beginning TestMultiThreadInt
TestMultiThreadInt Time 00:00:00.6490421
***** MyApp.MultiCoreTests.TestMultiThreadName
Beginning TestMultiThreadName
TestMultiThreadName Time 00:00:02.3353270
***** MyApp.MultiCoreTests.TestSingleThreadInt
Beginning TestSingleThreadInt
TestSingleThreadInt Time 00:00:01.0017084
***** MyApp.MultiCoreTests.TestSingleThreadString
Beginning TestSingleThreadString
TestSingleThreadString Time 00:00:04.6166498


windows mono

Running test with 2 cores and 400000 items
***** MyApp.MultiCoreTests.TestMultiThreadInt
Beginning TestMultiThreadInt
TestMultiThreadInt Time 00:00:00.3894325
***** MyApp.MultiCoreTests.TestMultiThreadName
Beginning TestMultiThreadName
TestMultiThreadName Time 00:00:16.9111039
***** MyApp.MultiCoreTests.TestSingleThreadInt
Beginning TestSingleThreadInt
TestSingleThreadInt Time 00:00:00.6319084
***** MyApp.MultiCoreTests.TestSingleThreadString
Beginning TestSingleThreadString
TestSingleThreadString Time 00:00:29.8346654


linux mono

ProcessModel: Default    DomainUsage: Single
Execution Runtime: mono-2.0
Running test with 2 cores and 400000 items
.Beginning TestMultiThreadInt
TestMultiThreadInt Time 00:00:00.3695696
.Beginning TestMultiThreadName
TestMultiThreadName Time 00:00:18.2811198
.Beginning TestSingleThreadInt
TestSingleThreadInt Time 00:00:00.6757025
.Beginning TestSingleThreadString
TestSingleThreadString Time 00:00:33.9977345


----------------

and here is my code:

    [TestFixture]
    public class MultiCoreTests
    {

        private readonly TestObj[][] m_input = new
TestObj[Environment.ProcessorCount][];
        private const int NUM_ITEMS = 400000;

        [TestFixtureSetUp]
        public void TestFixtureSetup()
        {
            if(Environment.ProcessorCount == 1)
                throw new IgnoreException("Cannot run this
multithreaded test on a machine with only one core.");

            Console.Out.WriteLine("Running test with {0} cores and {1}
items", Environment.ProcessorCount, NUM_ITEMS);

        }



        [SetUp]
        public void SetUp()
        {
            var r = new Random(12345);
            for (int i = 0; i < m_input.Length; i ++ )
            {
                m_input[i] = new TestObj[NUM_ITEMS];

                for(var j = 0; j < m_input[i].Length; j++)
                {
                    m_input[i][j] = new TestObj()
                                        {
                                            ID = r.Next(),
                                            Name =
string.Format("TestObj-{0}-{1}", r.Next(), r.Next())
                                        };
                }
            }
        }

        [Test]
        public void TestSingleThreadInt()
        {
            Console.WriteLine("Beginning TestSingleThreadInt");
            var stopwatch = new Stopwatch();
            stopwatch.Start();
            foreach (var t in m_input)
            {
                Array.Sort(t, (x, y) => x.ID.CompareTo(y.ID));
            }

            stopwatch.Stop();

            Console.WriteLine("TestSingleThreadInt Time {0}",
stopwatch.Elapsed);
        }

        [Test]
        public void TestSingleThreadString()
        {
            Console.WriteLine("Beginning TestSingleThreadString");
            var stopwatch = new Stopwatch();
            stopwatch.Start();
            foreach (var t in m_input)
            {
                Array.Sort(t, (x, y) => x.Name.CompareTo(y.Name));
            }

            stopwatch.Stop();

            Console.WriteLine("TestSingleThreadString Time {0}",
stopwatch.Elapsed);
        }


        [Test]
        public void TestMultiThreadInt()
        {
            var threads = new List<Thread>();

            for(var i = 0; i < Environment.ProcessorCount; i ++)
            {
                var i1 = i;
                threads.Add(new Thread(
                                () => Array.Sort(m_input[i1],
                                                 (x, y) =>
x.ID.CompareTo(y.ID))));
            }

            Console.WriteLine("Beginning TestMultiThreadInt");
            var stopwatch = new Stopwatch();
            stopwatch.Start();
            foreach (var thread in threads)
                thread.Start();
            foreach (var thread in threads)
                thread.Join();

            stopwatch.Stop();

            Console.WriteLine("TestMultiThreadInt Time {0}", stopwatch.Elapsed);

        }

        [Test]
        public void TestMultiThreadName()
        {
            var threads = new List<Thread>();

            for (var i = 0; i < Environment.ProcessorCount; i++)
            {
                var i1 = i;
                threads.Add(new Thread(
                                () => Array.Sort(m_input[i1],
                                                 (x, y) =>
x.Name.CompareTo(y.Name))));
            }

            Console.WriteLine("Beginning TestMultiThreadName");
            var stopwatch = new Stopwatch();
            stopwatch.Start();
            foreach (var thread in threads)
                thread.Start();
            foreach (var thread in threads)
                thread.Join();

            stopwatch.Stop();

            Console.WriteLine("TestMultiThreadName Time {0}",
stopwatch.Elapsed);

        }



        class TestObj
        {
            public int ID { get; set; }
            public String Name { get; set; }
        }
    }