using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace TestConsoleApp
{
  /// <summary>
  ///C#慢查詢解決： 線程并行實(shí)現(xiàn)處理
  /// </summary>
  class Program
  {
    static void Main(string[] args)
    {
      List<Task> taskList = new List<Task>();
      int count = 100;
      int batch = count % 10;
      object lockObj = new object();
      List<int> list = new List<int>();

      ///開(kāi)啟線程并行執(zhí)行
      Stopwatch stopwatch = new Stopwatch();
      stopwatch.Start();
      for (int i = 0; i < batch; i++)
      {
        taskList.Add(Task.Run(() =>
        {
          for (int j = count * i; j < count * (i + 1); j++)
          {
            ///休眠等待，模擬慢查詢需要消耗的時(shí)間
            Thread.Sleep(100);
            ///核心邏輯：避免線程插入沖突
            lock (lockObj)
            {
              list.Add(i);
            }
          }
        }));
      }
      ///這里核心是等待所有的線程結(jié)束，然后再執(zhí)行下去
      Task.WaitAll(taskList.ToArray());
      ///這里再內(nèi)存處理排序，避免返回的結(jié)果跟正常查詢出來(lái)的結(jié)果排序不一致
      list = list.OrderByDescending(u => u).ToList();
      Console.WriteLine(stopwatch.ElapsedMilliseconds);


      Console.WriteLine("**********分割線***********");

      ///原始遍歷實(shí)現(xiàn)
      List<int> list2 = new List<int>();
      Stopwatch stopwatch2 = new Stopwatch();
      stopwatch2.Start();
      for (int i = 0; i < count; i++)
      {
        ///休眠等待，模擬慢查詢需要消耗的時(shí)間
        Thread.Sleep(100);
        list2.Add(i);
      }
      Console.WriteLine(stopwatch2.ElapsedMilliseconds);
      Console.ReadLine();
    }
  }
}