如何确保Windows服务定时器产生的线程在停止Windows服务后完成执行？

Question

我正在使用System.Timers.Timer构建Windows服务。计时器委托计算的任务可能需要几秒到几分钟。我想确保当服务停止时，所有委派的线程在处理之前都处于完成状态。

这是代码，但是它没有达到我期望的效果，因为如果Windows服务在运行时停止，当前运行的线程永远不会完成。

public abstract class AgentServiceBase : ServiceBase 
{ 
    private System.ComponentModel.IContainer components = null; 
    private System.Timers.Timer _Timer; 
    private string _logPath; 
    private const int MAXNUMBEROFTHREADS = 10; 
    protected int interval = 25000; 
    protected int numberOfAllowedThreads = 2; 

    public AgentServiceBase() 
    { 
     this.InitializeComponent(); 
     this._logPath = (Path.GetDirectoryName(Assembly.GetAssembly(this.GetType()).CodeBase)).Substring(6).Replace("/", @"\"); 
    } 

    protected override void OnStart(string[] args) 
    { 
     if (args.Length > 0) 
     { 
      int.TryParse(args[0], out interval); 
     } 

     if (args.Length > 1) 
     { 
      int.TryParse(args[1], out numberOfAllowedThreads); 
      if (numberOfAllowedThreads > MAXNUMBEROFTHREADS) 
      { 
       numberOfAllowedThreads = MAXNUMBEROFTHREADS; 
      } 
      if (numberOfAllowedThreads == 1) 
      { 
       numberOfAllowedThreads = 2; 
      } 
     } 

     ThreadPool.SetMaxThreads(numberOfAllowedThreads, numberOfAllowedThreads); 

     this._Timer = new System.Timers.Timer(); 
     this._Timer.Elapsed += new ElapsedEventHandler(PollWrapper); 
     this._Timer.Interval = this.interval; 
     this._Timer.Enabled = true; 

    } 

    protected override void OnStop() 
    { 
     this._Timer.Enabled = false; 

     Process currentProcess = Process.GetCurrentProcess(); 

     foreach (Thread t in currentProcess.Threads) 
     { 
      t.Join(); 
     } 

    } 
    /// <summary> 
    protected override void Dispose(bool disposing) 
    { 
     if (disposing && (components != null)) 
     { 
      components.Dispose(); 
     } 
     base.Dispose(disposing); 
    } 

    private void InitializeComponent() 
    { 
     components = new System.ComponentModel.Container(); 
     this.ServiceName = "Agent Service - Johnhenry"; 

    } 

    private void PollWrapper(object sender, ElapsedEventArgs e) 
    { 
     try 
     { 
      this.Poll(sender, e); 
     } 
     catch (Exception exception) 
     { 
      string message = this.GetType().FullName + " - Windows Service Exception\n"; 
      message += exception.GetNestedExceptionInSingleStringOutput(); 

      FileHelper.Log(message, this._logPath, "exception", FileHelper.LogFileNameChangeFrequency.DAYLY); 
     } 
    } 

    protected abstract void Poll(object sender, ElapsedEventArgs e); 
} 

非常感谢，

朱塞佩

UPDATE：

与计数当前进程的自己的线程我最终与使用计数器的简单的解决方案解决一些不同的尝试之后计时器启动的线程仍在运行。基于此，我在主线程上调用Sleep并发出RequestAdditionalTime，直到所有线程都结束。 按照修订后的2种方法：

protected override void OnStop() 
    { 
     this._Timer.Enabled = false; 

     while (numberOfRunningThreads > 0) 
     { 
      this.RequestAdditionalTime(1000); 
      Thread.Sleep(1000); 
     } 

    } 



    private void PollWrapper(object sender, ElapsedEventArgs e) 
    { 
     numberOfRunningThreads++; 

     try 
     { 
      this.Poll(sender, e); 
     } 
     catch (Exception exception) 
     { 
      string message = this.GetType().FullName + " - Windows Service Exception\n"; 
      message += exception.GetNestedExceptionInSingleStringOutput(); 

      FileHelper.Log(message, this._logPath, "exception", FileHelper.LogFileNameChangeFrequency.DAYLY); 
     } 
     finally 
     { 
      numberOfRunningThreads--; 
     } 
    } 

Answer 1

你可以通过调用RequestAdditionalTime只要你的线程都没有在你的实现OnStop环内完成了这项工作，但（前和/或调用后实现这一目标Join()）。

但要注意 Windows可以会不耐烦并决定杀死你的Windows服务 - 例如关闭期间...

欲了解更多信息，请参阅http://msdn.microsoft.com/en-us/library/system.serviceprocess.servicebase.aspx