如何知道什麼時候我所有的生產者 - 消費者作業完成

Question

我有Winforms應用程序，閱讀一些網絡文件夾和搜索該文件夾中的文件，這個功能得到List<stirng> folders：

private decimal _numberOfFiles; 
private static List<string> _folders; 
public delegate void OnFileAddDelegate(List<string> files); 
public event OnFileAddDelegate OnFileAddEventHandler; 
public delegate void OnFinishSearchDelegate(); 
public event OnFinishSearchDelegate OnFinishSearchEventHandler; 

public void SearchFiles() 
{ 
    foreach (string folder in _folders) 
    { 
     if (Directory.Exists(folder)) 
     { 
      var files = Directory.EnumerateFiles(folder, "*.doc", SearchOption.TopDirectoryOnly) 
       .OrderByDescending(x => new FileInfo(x).CreationTime).Take((int)_numberOfFiles).ToList<string>(); 
      if (OnFileAddEventHandler != null) 
       OnFileAddEventHandler(files); 
     } 
    } 

    if (OnFinishSearchEventHandler != null) 
     OnFinishSearchEventHandler(); 
} 

後OnFileAddEventHandler(files)事件被激發我ProducerConsumer類開始檢查這List是找到的文件和所做的工作（如果文件被確定解僱了事件到我的主UI添加這個文件到我的ListView）：

public class ProducerConsumer 
{ 
    public delegate void OnFileAddDelegate(PcapFileDetails pcapFileDetails); 
    public event OnFileAddDelegate OnFileAddEventHandler; 
    public delegate void AllFilesProcessedDelegate(); 
    public event AllFilesProcessedDelegate AllFilesProcessedEventHandler; 
    private readonly Queue<string> _queue; 
    private int counter; 

    public ProducerConsumer(int workerCount, IEnumerable<string> list) 
    { 
     _isSearchFinished = true; 
     _queue = new Queue<string>(list); // fill the queue 
     counter = _queue.Count; // set up counter 
     for (int i = 0; i < workerCount; i++) 
      Task.Factory.StartNew(Consumer); 
    } 

    private void Consumer() 
    { 
     FileChecker fileChecker = new FileChecker(); 
     for (; ;) 
     { 
      string file; 
      lock (_queue) 
      { 
       // synchronize on the queue 
       if (_queue.Count == 0) return; // we are done 
       file = _queue.Dequeue(); // get file name to process 
      } // release the lock to allow other consumers to access the queue 
      // do the job 
      string result = fileChecker.Check(file); // Check my file 

      if (OnFileAddEventHandler != null && result) // In case my file OK, fired up event to my main UI 
       OnFileAddEventHandler(file); 

      // decrement the counter 
      if (Interlocked.Decrement(ref counter) != 0) 
       continue; // not the last 

      // all done - we were the last 
      if (AllFilesProcessedEventHandler != null) 
       AllFilesProcessedEventHandler(); 
      return; 
     } 
    } 
} 

現在，此搜索正在進行中，我的用戶界面被鎖定以防止不必要的點擊，並且我想知道我的所有文件夾何時完成搜索才能解鎖。 但我的問題是因爲我搜索幾個文件夾事件AllFilesProcessedEventHandler()發射了好幾次，我想知道什麼時候我所有的搜索結束。

Answer 1

這裏是QuickIO.Net

using System; 
using System.Collections.Concurrent; 
using System.Threading; 
using System.Threading.Tasks; 
using SchwabenCode.QuickIO; 

namespace ConsoleApplication3 
{ 
    internal class Program 
    { 
     private static readonly BlockingCollection<QuickIOFileInfo> fileInfos = new BlockingCollection<QuickIOFileInfo>(); 
     private static void Main(string[] args) 
     { 
      var task = Task.Factory.StartNew(() => 
      { 
       Int32 totalSize = 0; 
       Parallel.ForEach(fileInfos.GetConsumingEnumerable(), fi => 
       { 
        Interlocked.Add(ref totalSize, (int)fi.Bytes); 
       }); 
       Console.WriteLine("All docs bytes amount to {0}", totalSize); 
      }); 

      ProcessDirectory("C:\\"); 
      fileInfos.CompleteAdding(); 

      Task.WaitAll(task); 
     } 

     private static void ProcessDirectory(string path) 
     { 
      Parallel.ForEach(QuickIODirectory.EnumerateDirectories(path), dir => 
      { 
       try 
       { 
        Parallel.ForEach(QuickIODirectory.EnumerateFiles(dir), file => 
        { 
         if (file.AsFileInfo().Extension.Equals(".docx")) 
          fileInfos.Add(file); 
        }); 
        ProcessDirectory(dir.FullName); 
       } 
       catch (Exception e) 
       { 
        Console.WriteLine("Unable to access directory {0}", dir.FullName); 
       } 
      }); 
     } 
    } 
} 

阻塞收集將自動用信號時的所有元素已經被添加，通過調用CompleteAdding到並行的ForEach（）的遞歸樣品。

要掃描一個256GB的SSD，剩下74GB和總共738k +文件花費16.8s。