对象池的实现与性能测试

引用对象池的好处：从池中操作对象比直接new、free要性能更快，且能避免内存碎片的堆积

先贴对象池的代码：

    public abstract class ObjectBase
    {
        public abstract void Init(params object[] paramList);
    }

    //对象池管理器(采用堆栈存储，支持动态扩容，支持多线程，新扩容的则自动加入到池中能被重复利用)
    public class ObjectPoolManager<T> where T : ObjectBase, new()
    {
        private static ObjectPoolManager<T> instance = null;
        private int blockCapacity = 1000;
        private static object doubleCheckLock = new object();
        private static object objLock = new object();
        private bool inited = false;
        private ConcurrentDictionary<string, Stack<T>> objectPool = new ConcurrentDictionary<string, Stack<T>>();

        private ObjectPoolManager() { }

        public static ObjectPoolManager<T> Instance
        {
            get
            {
                if (instance == null)
                {
                    lock (doubleCheckLock)
                    {
                        if (instance == null)
                        {
                            instance = new ObjectPoolManager<T>();
                        }
                    }
                }
                return instance;
            }
        }

        //初始化对象池
        public string Init(int blockCapacity)
        {
            lock (objLock)
            {
                try
                {
                    if (blockCapacity < 1 || blockCapacity > int.MaxValue)
                    {
                        this.blockCapacity = 1000;
                    }
                    else
                    {
                        this.blockCapacity = blockCapacity;
                    }
                    Stack<T> freeObjList = new Stack<T>();
                    for (int index = 0; index < blockCapacity; index++)
                    {
                        T obj = new T();
                        freeObjList.Push(obj);
                    }
                    objectPool[typeof(T).ToString()] = freeObjList;
                    inited = true;
                    return null;
                }
                catch (Exception ex)
                {
                    return typeof(T).ToString() + " -> ExceptionMessage:" + ex.Message + (ex.InnerException != null ? ("InnerExceptionMessage:" + ex.InnerException.Message) : "");
                }
            }
        }
        //取新对象
        public T NewObject(params object [] paramList)
        {
            lock (objLock)
            {
                try
                {
                    if (!inited)
                    {
                        Init(blockCapacity);
                    }

                    string key = typeof(T).ToString();
                    Stack<T> objList = objectPool[key];

                    if (objList.Count > 0)
                    {
                        T obj = objList.Pop();
                        obj.Init(paramList);
                        return obj;
                    }
                    else
                    {
                        for (int index = 0; index < this.blockCapacity; index++)
                        {
                            T newObj = new T();
                            objList.Push(newObj);
                        }
                        T obj = objList.Pop();
                        obj.Init(paramList);
                        return obj;
                    }
                }
                catch (Exception ex)
                {
                    //ServerUtil.RecordLog(LogType.Error, ex);
                    T newObj = new T();
                    newObj.Init(paramList);
                    return newObj;
                }
            }
        }
        //释放对象
        public void FreeObject(T obj)
        {
            lock (objLock)
            {
                try
                {
                    if (obj == default(T)) return;

                    Stack<T> objList = objectPool[typeof(T).ToString()];
                    if (!objList.Contains(obj)) 
                    {
                        objList.Push(obj);
                    }
                }
                catch (Exception ex)
                {
                    //ServerUtil.RecordLog(LogType.Error, ex);
                }
            }
        }
    }

下一步做与不用池时的性能测试对比：

先提供性能测试的支援函数

    //使用方法见本文档末尾
    public sealed class CodeElapseChecker
    {
        public static void Initialize()
        {
            Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
            Thread.CurrentThread.Priority = ThreadPriority.Highest;
            Time("初始化性能测试工具，该值不用考虑", 1, () => { });
        }

        public static void Time(string name, Action action, int iterationCnt = 1)
        {
            Time(name, iterationCnt, action);
        }
       

        public static void Time(string name, int iteration, Action action)
        {
            // 1.
            ConsoleColor currentForeColor = Console.ForegroundColor;
            Console.ForegroundColor = ConsoleColor.Yellow;
            Console.WriteLine(name);

            // 2.
            GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced);
            int[] gcCounts = new int[GC.MaxGeneration + 1];
            for (int i = 0; i <= GC.MaxGeneration; i++)
            {
                gcCounts[i] = GC.CollectionCount(i);
            }

            // 3.
            Stopwatch watch = new Stopwatch();
            watch.Start();
            long cycleCount = GetCycleCount();
            for (int i = 0; i < iteration; i++) action();
            long cpuCycles = GetCycleCount() - cycleCount;
            watch.Stop();

            // 4.
            Console.ForegroundColor = currentForeColor;
            Console.WriteLine("\tTime Elapsed:\t" + watch.ElapsedMilliseconds.ToString("N0") + "ms");
            Console.WriteLine("\tCPU Cycles:\t" + cpuCycles.ToString("N0"));

            // 5.
            for (int i = 0; i <= GC.MaxGeneration; i++)
            {
                int count = GC.CollectionCount(i) - gcCounts[i];
                Console.WriteLine("\tGen " + i + ": \t\t" + count);
            }

            Console.WriteLine();

        }

        private static long GetCycleCount()
        {
            //ulong cycleCount = 0;
            //QueryThreadCycleTime(GetCurrentThread(), ref cycleCount);
            //return cycleCount;
            return GetCurrentThreadTimes();
        }

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool GetThreadTimes(IntPtr hThread, out long lpCreationTime,
           out long lpExitTime, out long lpKernelTime, out long lpUserTime);

        private static long GetCurrentThreadTimes()
        {
            long l;
            long kernelTime, userTimer;
            GetThreadTimes(GetCurrentThread(), out l, out l, out kernelTime,
               out userTimer);
            return kernelTime + userTimer;
        }


        //[DllImport("kernel32.dll")]
        //[return: MarshalAs(UnmanagedType.Bool)]
        //static extern bool QueryThreadCycleTime(IntPtr threadHandle, ref ulong cycleTime);

        [DllImport("kernel32.dll")]
        static extern IntPtr GetCurrentThread();

    }

建立两个测试对象：

        //复杂测试对象1
        public class ComplexObject1 : ObjectBase
        {
            private byte[] data = new byte[1024];            
            public override void Init(params object[] paramList)
            {
            }
        }
        //复杂测试对象2
        class ComplexObject2 : ObjectBase
        {
            private byte[] data = new byte[1024 * 1024];
            public override void Init(params object[] paramList)
            {
            }
        }

测试代码：

class Program
    {
        const int Count1 = 1000000;
        const int Count2 = 500;

        static void Main(string[] args)
        {
            var list1 = new List<ComplexObject1>(Count1 * 2);
            var list2 = new List<ComplexObject2>(Count2 * 2);

            CodeElapseChecker.Initialize();

            ObjectPoolManager<ComplexObject1>.Instance.Init(Count1);
            ObjectPoolManager<ComplexObject2>.Instance.Init(Count2);           
            

            CodeElapseChecker.Time("TestComplexObject1", () => { list1.Add(new ComplexObject1()); }, Count1);
            CodeElapseChecker.Time("TestPooledComplexObject1", () => { list1.Add(ObjectPoolManager<ComplexObject1>.Instance.NewObject()); }, Count1);

            CodeElapseChecker.Time("TestComplexObject2", () => { list2.Add(new ComplexObject2()); }, Count2);
            CodeElapseChecker.Time("TestPooledComplexObject2", () => { list2.Add(ObjectPoolManager<ComplexObject2>.Instance.NewObject()); }, Count2);
            
            Console.WriteLine(list1.Count);
            Console.WriteLine(list2.Count);
        }
    }

运行测试结果：（采用Release、X64编译）