Parallel小记 

 1   　　　　　　List<Temp> tList = new List<Temp>();
 2             for (int i = 1; i < 1000; i++)
 3             {
 4                 tList.Add(new Temp()
 5                 {
 6                     id = i,
 7                     name = string.Concat("test", i),
 8                     age = i * 2
 9                 });
10             }
11             object obj = new object();
12             List<TempChild> resultList = new List<TempChild>();
13             Stopwatch sc = new Stopwatch();
14             Stopwatch sc1 = new Stopwatch();
15             Stopwatch sc2 = new Stopwatch();
16             sc.Start();
17             Parallel.ForEach(tList, item =>
18             {
19                 List<TempChild> tempChildList = LoadChildList();
20                 if (null != tempChildList && tempChildList.Count > 0)
21                 {
22                     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】
23                     {
24                         resultList.AddRange(tempChildList);
25                     }
26                 }
27             });
28             sc.Stop();
29             long second = sc.ElapsedMilliseconds;
30             List<TempChild> resultList1 = new List<TempChild>();
31             sc1.Start();
32             foreach (var item in tList)
33             {
34                 List<TempChild> tempChildList = LoadChildList();
35                 if (null != tempChildList && tempChildList.Count > 0)
36                 {
37                     resultList1.AddRange(tempChildList);
38                 }
39             }
40             sc1.Stop();
41             long second2 = sc1.ElapsedMilliseconds;
42 
43             sc2.Start();
44             List<TempChild> resultList2 = tList
45                 .AsParallel()
46                 .SelectMany(
47                 (item) =>
48                 {
49                     return LoadChildList();
50                 }).ToList();
51             sc2.Stop();
52             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。

 

posted on 2017-03-30 11:02  lb1208  阅读(197)  评论(0)  编辑  收藏  举报

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