奇了怪了..

泛型集合类的优势好象还是类型安全，性能方面好象没什么优势

下面那个测试写得有点急，写错了。

但不可理解的是明明ArrayList比List<T>多一步装箱操作，但测试结果确不能让人满意。

 

class Program
    ...{
        static void Main(string[] args)
        ...{
            Console.WriteLine("Constructor Time:");
            Program.TestConstruct();
            Console.WriteLine();
            Console.WriteLine("AddMechod Time:");
            Program.TestAddMethod();
            Console.WriteLine();
            Console.WriteLine("Loop Add Time:");
            Program.Test(10);
            Program.Test(100);
            Program.Test(1000);
            Program.Test(1000 * 1000);
            Program.Test(Int32.MaxValue);
            Console.ReadLine();
        }

        private static void Test(int times)
        ...{
            SomeValueTye temp; 
            IList<SomeValueTye> list = new List<SomeValueTye>();
            ArrayList al = new ArrayList();
            Stopwatch sw = new Stopwatch();  
          
            //List<T>,add操作
            sw.Start();           
            for (int i = 0; i < times; i++)
            ...{
                list.Add(new SomeValueTye(i, "test"));
            }
            sw.Stop();
            Console.WriteLine("IL In"  + " " + sw.Elapsed + " " + times.ToString());
            
            sw.Reset();
            
            //ArrayList, add操作
            sw.Start();            
            for (int i = 0; i < times; i++)
            ...{
                al.Add(new SomeValueTye(i, "test"));
            }            
            sw.Stop();
            Console.WriteLine("AL In" + " " + sw.Elapsed + " " + times.ToString());

            sw.Reset();

            //List<T>,取值
            sw.Start();
            for (int i = 0; i < times; i++)
            ...{
                temp = list[i];
            }
            sw.Stop();
            Console.WriteLine("IL Out" + " " + sw.Elapsed + " " + times.ToString());

            sw.Reset();

            //ArrayList,取值
            sw.Start();
            for (int i = 0; i < times; i++)
            ...{
                temp = (SomeValueTye)al[i];
            }
            sw.Stop();
            Console.WriteLine("AL Out" + " " + sw.Elapsed + " " + times.ToString());
            Console.WriteLine();
        }

        private static void TestConstruct()
        ...{
            Stopwatch sw = new Stopwatch();           
            sw.Start();
            for (int i = 0; i < 1000 * 1000; i++)
            ...{
                IList<SomeValueTye> list = new List<SomeValueTye>(10);
            }
            sw.Stop();
            Console.WriteLine("IL: " + sw.Elapsed);

            sw.Reset();

            sw.Start();
            for (int i = 0; i < 1000 * 1000; i++)
            ...{
                ArrayList al = new ArrayList(10);
            }
            sw.Stop();
            Console.WriteLine("AL: " + sw.Elapsed);
        }

        private static void TestAddMethod()
        ...{
            Stopwatch sw = new Stopwatch();            
            IList<SomeValueTye> list = new List<SomeValueTye>();
            sw.Start();
            for(int i = 0; i < 1000*1000; i++)
                list.Add(new SomeValueTye(1,"test"));
            sw.Stop();
            Console.WriteLine("IL: " + sw.Elapsed);

            sw.Reset();   
         
            ArrayList al = new ArrayList();
            sw.Start();
            for (int i = 0; i < 1000 * 1000; i++)
                al.Add(new SomeValueTye(1, "test"));
            sw.Stop();
            Console.WriteLine("AL: " + sw.Elapsed);
        }
    }

    struct SomeValueTye
    ...{
        public int m_TestInt;
        public string m_TestStr;
        public SomeValueTye(int intValue, string strValue)
        ...{
            m_TestInt = intValue;
            m_TestStr = strValue;
        }
    }

 运行结果:

Constructor Time:
IL:      00:00:00.1989778
AL:     00:00:00.1317960

AddMechod Time:
IL:      00:00:00.0932551
AL:     00:00:00.2032006

 

	1	10	100	1000	1000000
List<T>	572	212	430	782	1142039
ArrayList	164	162	215	1206	2112237

 

  IL_0020:  newobj     instance void IList.SomeValueTye::.ctor(int32,
                                                               string)
  IL_0025:  callvirt   instance void /**//* UNKNOWN TYPE (0x15)*/::Add(!0)

  IL_0083:  newobj     instance void IList.SomeValueTye::.ctor(int32,
                                                               string)
  IL_0088:  box        IList.SomeValueTye
  IL_008d:  callvirt   instance int32 [mscorlib]System.Collections.ArrayList::Add(object)

Why?