Parallel小记

  　　　　　　List<Temp> tList = new List<Temp>();
            for (int i = 1; i < 1000; i++)
            {
                tList.Add(new Temp()
                {
                    id = i,
                    name = string.Concat("test", i),
                    age = i * 2
                });
            }
            object obj = new object();
            List<TempChild> resultList = new List<TempChild>();
            Stopwatch sc = new Stopwatch();
            Stopwatch sc1 = new Stopwatch();
            Stopwatch sc2 = new Stopwatch();
            sc.Start();
            Parallel.ForEach(tList, item =>
            {
                List<TempChild> tempChildList = LoadChildList();
                if (null != tempChildList && tempChildList.Count > 0)
                {
                    lock (obj)//一定要加锁，不然会出异常【目标数组长度不够，请检查destIndex和长度以及数组下限】
                    {
                        resultList.AddRange(tempChildList);
                    }
                }
            });
            sc.Stop();
            long second = sc.ElapsedMilliseconds;
            List<TempChild> resultList1 = new List<TempChild>();
            sc1.Start();
            foreach (var item in tList)
            {
                List<TempChild> tempChildList = LoadChildList();
                if (null != tempChildList && tempChildList.Count > 0)
                {
                    resultList1.AddRange(tempChildList);
                }
            }
            sc1.Stop();
            long second2 = sc1.ElapsedMilliseconds;

            sc2.Start();
            List<TempChild> resultList2 = tList
                .AsParallel()
                .SelectMany(
                (item) =>
                {
                    return LoadChildList();
                }).ToList();
            sc2.Stop();
            long second3 = sc2.ElapsedMilliseconds;

   private static List<TempChild> LoadChildList()
        {
            List<TempChild> tList = new List<TempChild>();
            for (int i = 1; i < 100; i++)
            {
                tList.Add(new TempChild()
                {
                    id = i,
                    name = string.Concat("test", i),
                    age = i * 2,
                    addr = i.ToString()
                });
            }
            return tList;
        }

　　分别对不同数据量级的并行任务执行对比，三种方式结果如下：

　　

　　

　　

　　

　　

　　百万数量级，电脑崩了，没有测试结果~@@！！

　　由此，一般的list没必要并行执行，foreach足以。