c#多线程开发

  1

        //要执行的业务是从阿里云上下载将近40000条的音频到本地，单条下载忒慢，就想采用多线程，分配了二十个线程同时下载，省了很大部分的时间

          class Program
  2     {
  3        
  4         static void Main(string[] args) {
  5             string sql = "select en_audio,us_audio from t_audio LIMIT 198 ";
  6             MySqlDataReader mySqlDataReader = DBHelper.ExecuteReader(sql);         
  7             List<String> sList = new List<String>();
  8             sList.Add("https://qutifen-qudao.oss-cn-beijing.aliyuncs.com/mfg/audio/v3/1abacus_en.ogg");
  9             sList.Add("https://qutifen-qudao.oss-cn-beijing.aliyuncs.com/mfg/audio/v3/2abacus_en.ogg");
 10             if (mySqlDataReader.HasRows)
 11             {
 12                 while (mySqlDataReader.Read())
 13                 {                 
 14                     sList.Add(mySqlDataReader.GetString(0));
 15                     sList.Add(mySqlDataReader.GetString(1));
 16                 }
 17             }              
 18             Console.WriteLine(sList.Count);
 19             Stopwatch stopwatch = new Stopwatch();
 20             stopwatch.Start();
 21             ThreadStart(sList);
 22             WaitHandle.WaitAll(waits);  //监听wait里面的所有的线程都已经set了 才执行下面的代码，否则一直在这里等待
 23             stopwatch.Stop();
 24             Console.WriteLine($"耗时{stopwatch.ElapsedMilliseconds}毫秒");
 25             Console.ReadKey();
 26 
 27 
 28         }
 29        static  Thread[] threads = new Thread[20];
 30         static WaitHandle[] waits = new WaitHandle[20];
 31         public  static void ThreadStart(List<String> nums) {
                  //分配线程
 32             for (int i=0;i<20;i++) {
 33                 threads[i] = new Thread(DownLoadFile);
 34                 waits[i] = new AutoResetEvent(false);
 35 
 36             }
                 //为每个线程分配要执行的数据并开始执行
 37             for (int i = 0; i < 20; i++)
 38             {
 39                 if (i== threads.Length-1) {
 40                     var retult = nums.Skip(nums.Count / 20 * i).Take(nums.Count- nums.Count / 20*i).ToList();
 41                     threads[i].Start(new Objpt()
 42                     {
 43                         sList = retult,
 44                         WaitHandle = waits[i],
 45                         ThreadIndex = i
 46                     });
 47                 }
 48                 else {
 49                   var retult= nums.Skip(nums.Count / 20 * i).Take(nums.Count / 20).ToList();
 50                     threads[i].Start(new Objpt() { 
 51                      sList= retult,
 52                      WaitHandle=waits[i],
 53                      ThreadIndex=i
 54                     });
 55                 }
 56                
 57             }
 58         }
 59 
 60         public static void DownLoadFile(Object obj)
 61         {
 62             int count = 0;
 63             Objpt optObj = (obj as Objpt);
 64             var sList = optObj.sList;
 65             Console.WriteLine($"线程{optObj.ThreadIndex}开始了");
 66             foreach (var url in sList)
 67             {
 68                 try
 69                 {
 70                     count++;
 71                     var arrs = url.Split('/');
 72                     WebRequest request = WebRequest.Create(url);
 73                     HttpWebResponse res = (HttpWebResponse)request.GetResponse();
 74                     WebResponse response = request.GetResponse();           
 75                     if (res.StatusCode.ToString() == "OK")
 76                     {
 77                         Stream responseStream = response.GetResponseStream();
 78                         using (FileStream fsWrite = new FileStream($"F:/Audio/v4/{arrs[arrs.Length - 2]}/{arrs[arrs.Length - 1]}", FileMode.OpenOrCreate, FileAccess.Write))
 79                         {
 80                             byte[] buffer = new byte[response.ContentLength];
 81                             while (true)
 82                             {
 83                                 ////返回本次实际读取到的字节数
 84                                 int r = responseStream.Read(buffer, 0, buffer.Length);
 85                                 if (r == 0)
 86                                 {
 87                                     break;
 88                                 }
 89                                 fsWrite.Write(buffer, 0, r);///写入
 90 
 91                             }
 92                         }
 93                     }
 94                     //if (count % 20 == 0 || count == sList.Count)
 95                     //{
 96                     //    Console.WriteLine($"线程{optObj.ThreadIndex}已处理个数：{count}");
 97                     //}
 98 
 99                 }
100                 catch (Exception ex)
101                 {
102                     string strErrorLogFile = System.AppDomain.CurrentDomain.BaseDirectory + $"\\{optObj.ThreadIndex}ErrorLog.log";
103                     if (!System.IO.File.Exists(strErrorLogFile))
104                         System.IO.File.WriteAllText(strErrorLogFile, "//系统错误日志记录文件\r\n");
105                     object objSql ="线程"+ optObj.ThreadIndex.ToString()+ ex.Message;
106                     System.IO.File.AppendAllText(strErrorLogFile, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + "\t" + objSql.ToString() + url + "\r\n");
107 
108                 }
109 
110             }
111             Console.WriteLine($"线程{optObj.ThreadIndex}结束");
112             (optObj.WaitHandle as AutoResetEvent).Set();  //set方法是当某个线程结束起做个标记的作用
113         }
114     }
115 
116      public class Objpt {
117         public List<String> sList { get; set; }
118         public WaitHandle WaitHandle { get; set; }
119         public int ThreadIndex { get; set; }
120 
121     }