using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WCF_Host_Service
{
    /// <summary>
    /// 服务程序唯一上下文对象(单例)
    /// </summary>
    public sealed  class ServiceContext
    {
        private static ServiceContext _ServiceContext = null;
        private readonly static object lockObj = new object();
        /// <summary>
        /// 禁止外部进行实例化
        /// </summary>
        private ServiceContext()
        {

        }
        /// <summary>
        /// 获取唯一实例，双锁定防止多线程并发时重复创建实例
        /// </summary>
        /// <returns></returns>
        public static ServiceContext GetInstance()
        {
            if (_ServiceContext == null)
            {
                lock (lockObj)
                {
                    if (_ServiceContext == null)
                    {
                        _ServiceContext = new ServiceContext();
                    }
                }
            }
            return _ServiceContext;
        }
    }
}

ConcurrentDictionary<int, ServiceContext> dict = new ConcurrentDictionary<int, ServiceContext>();
                Action testTask = () =>
                {
                    ServiceContext sc = ServiceContext.GetInstance();
                    if (sc != null && !dict.ContainsKey(sc.GetHashCode()))
                    {
                        dict.TryAdd(sc.GetHashCode(), sc);
                    }
                    Thread.Sleep(1);
                }; 
                int index = 0;
                while (index < 1024)
                {                    
                    Parallel.Invoke(testTask,testTask);
                    index++;
                }
                Debugger.Log(0,"",string.Format("测试共生出{0}个实例。",dict.Count));

var type = this.GetType().Assembly.GetType(typeof(ServiceContext).FullName);
                    var sc = Activator.CreateInstance(type);