并行学习小结

并行学习小结，直接上源代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Threading.Tasks;
using System.Threading;
using System.Diagnostics;
using System.Collections.Concurrent;

public partial class test : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        UseParallel();
        UsePLINQ();
    }
    
    /// <summary>
    /// PLINQ的基本方法应用集合
    /// </summary>
    private void UsePLINQ()
    {
        #region 并行集合运算，Environment.ProcessorCount - 1 给一个处理器出来处理其他任务
        ConcurrentDictionary<int, string> cds = new ConcurrentDictionary<int, string>();//并行考虑用的集合
        Parallel.For(0, 3000, i =>
        {
            cds.TryAdd(i, Math.Sqrt(i).ToString());
        });
        var q1 = from c in cds.Values.AsParallel().WithDegreeOfParallelism(Environment.ProcessorCount - 1)
                 select c;//直接获取该集合,Environment.ProcessorCount - 1 给一个处理器出来处理其他任务
        #endregion

        #region 并行常用的运算
        ConcurrentBag<int> bags = new ConcurrentBag<int>();//线程安全的集合
        var list = ParallelEnumerable.Range(0,3000);//生成并行集合
        list.ForAll(i => {
            bags.Add(i);
        });
        Response.Write("bags长度：" + bags.Count+"<br/>");
        Response.Write("list整数和：" + list.Sum() + "<br/>");
        Response.Write("list最大值：" + list.Max() + "<br/>");
        Response.Write("list最小值：" + list.Min() + "<br/>");
        Response.Write("list平均值：" + list.Average() + "<br/>");
        Response.Write("list默认值：" + list.FirstOrDefault() + "<br/>");

        #endregion

        #region 先并行分组，在对每组并行查询统计
        List<Student> list2 = new List<Student>() 
        { 
            new Student() 
            { 
                ID = 1, 
                Name = "jack", 
                Age = 20 
            }, 
            new Student() 
            { 
                ID = 1,
                Name = "mary", 
                Age = 25 
            }, 
            new Student() 
            { 
                ID = 1, 
                Name = "joe", 
                Age = 29 
            }, 
            new Student() 
            { 
                ID = 1, 
                Name = "Aaron", 
                Age = 25 
            }
        };
        var map = list2.AsParallel().ToLookup(i => i.Age,count=>1);//化简统计        
        var reduce = from IGrouping<int, int> singleMap                     
                     in map.AsParallel()                     
                     select new                     
                     {
                         Age = singleMap.Key,
                         Count = singleMap.Count()
                     };
        reduce.ForAll(i =>{
            Response.Write(string.Format("当前Age={0}的人数有:{1}人<br/>", i.Age, i.Count));        
        });
        #endregion

        foreach (var o in q1)
        {
            Response.Write(o + "<br/>");
        }
    }

    /// <summary>
    /// Parallel的基本使用方法集合
    /// </summary>
    private void UseParallel()
    {
        #region 并行查询和并行输出
        List<string> lists = new List<string>();
        for (int i = 0; i < 1000; i++)
        {
            lists.Add(i.ToString());
        }
        var q1 = from p in lists.AsParallel()
                 where Convert.ToInt32(p) > 100
                 select p;// 并行查询
        q1.ForAll<string>(p =>
        {
            Response.Write(p + "<br/>");//并行输出，注意观察输出结果不是有序的
        });
        #endregion

        #region 串行执行任务
        Stopwatch sw = new Stopwatch();
        sw.Start();
        Run1();
        Run2();
        Response.Write("串行执行时间:" + sw.ElapsedMilliseconds + "<br/>");
        #endregion

        #region 并行执行任务
        sw.Restart();
        Parallel.Invoke(Run1, Run2);
        Response.Write("并行执行时间:" + sw.ElapsedMilliseconds + "<br/>");
        #endregion

        #region 并行赋值
        List<int> mylist = new List<int>();
        Parallel.ForEach(Partitioner.Create(0, 5000), i =>
        {
            for (int m = i.Item1; m < i.Item2; m++)
            {
                mylist.Add(m);
            }
        });
        #endregion

        #region 并行 退出循环 Break和Stop
        List<int> mylist2 = new List<int>();
        Parallel.For(0, 5000, (i, state) =>
        {
            if (mylist2.Count == 50)
            {
                state.Break();
                return;
            }
            mylist2.Add(i);
        });
        #endregion

        #region 并行抛出异常处理
        try
        {
            Parallel.Invoke(Run1, Run2, Run3);
        }
        catch (AggregateException ex)
        {
            foreach (var single in ex.InnerExceptions)
            {
                Response.Write(single.Message + "<br/>");
            }
        }
        #endregion
    }

    private void Run1()
    {
        Thread.Sleep(3000);
    }

    private void Run2()
    {
        Thread.Sleep(5000);
    }

    private void Run3()
    {
        Thread.Sleep(1000);
    }

    private void Run4(int ms)
    {
        Thread.Sleep(ms * 100);
    }
}

public class Student { 
    public int ID { get; set; } 
    public string Name { get; set; } 
    public int Age { get; set; } 
    public DateTime CreateTime { get; set; } 
}