C# concurrent test. (lock, Interlocked, ReaderWriterLock)

C# concurrent test. (lock, Interlocked, ReaderWriterLock)

using System;
using System.Diagnostics;
using System.Threading;

namespace ConcurrentTest
{
    class Program
    {
        const int CONCURRENT = 100;
        const int LOOP = 100000;
        static void Main(string[] args)
        {
            char mode = (args.Length == 0) ? (char)0 :
                        (args[0] == "-l") ? 'l' :
                        (args[0] == "-i") ? 'i' :
                        (args[0] == "-w") ? 'w' :
                                             (char)1;
            if (mode == 1)
            {
                throw new ArgumentException("-i or -l or -w");
            }
            int expected = CONCURRENT * LOOP;
            int counter = 0;
            ThreadStart ts = null;
            if (mode == 0)
            {
                Console.WriteLine("unuse lock.");
                ts = new ThreadStart(delegate
                {
                    for (int j = 0; j < LOOP; j++)
                    {
                        counter++;
                    }
                });
            }
            else if (mode == 'l')
            {
                Console.WriteLine("lock.");
                object o = new object();
                ts = new ThreadStart(delegate
                {
                    for (int j = 0; j < LOOP; j++)
                    {
                        lock (o) { counter++; }
                    }
                });
            }
            else if (mode == 'i')
            {
                Console.WriteLine("Interlocked.");
                ts = new ThreadStart(delegate
                {
                    for (int j = 0; j < LOOP; j++)
                    {
                        Interlocked.Increment(ref counter);
                    }
                });
            }
            else if (mode == 'w')
            {
                Console.WriteLine("ReaderWriterLock lock.");
                ReaderWriterLock rwLock = new ReaderWriterLock();
                ts = new ThreadStart(delegate
                {
                    for (int j = 0; j < LOOP; j++)
                    {
                        try
                        {
                            rwLock.AcquireWriterLock(Timeout.Infinite);
                            counter++;
                        }
                        finally
                        {
                            rwLock.ReleaseWriterLock();
                        }
                    }
                });
            }

            Thread[] threads = new Thread[CONCURRENT];
            for (int i = 0; i < threads.Length; ++i)
            {
                int ID = i;
                threads[i] = new Thread(ts);
            }
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            for (int i = 0; i < threads.Length; ++i)
            {
                threads[i].Start();
            }
            for (int i = 0; i < threads.Length; ++i)
            {
                threads[i].Join();
            }
            stopWatch.Stop();
            Console.WriteLine("counter : {0:#,##0}", counter);
            Console.WriteLine("expected: {0:#,##0}", expected);
            Console.WriteLine("time: {0}(ms)", stopWatch.ElapsedMilliseconds);
        }
    }
}