VB .Net服务在线程休眠时不会停止

Question

我有一个VB .Net服务，它使用System.Threading而不是定时器来基本上做一个定时器应该做的事情。我的问题是在线程处于睡眠状态时停止服务。请参见下面的代码：服务启动

如果例如1分钟后

Imports System.Threading 

Public Class AService 
    Private stopping As Boolean 
    Private stoppedEvent As ManualResetEvent 

    Public Sub New() 
     InitializeComponent() 
     Me.stopping = False 
     Me.stoppedEvent = New ManualResetEvent(False) 
    End Sub 

    Protected Overrides Sub OnStart(ByVal args() As String) 
     ' Add code here to start your service. This method should set things 
     ' in motion so your service can do its work. 
    End Sub 

    Protected Overrides Sub OnStop() 
     ' Add code here to perform any tear-down necessary to stop your service. 
     Me.stopping = True 
     Me.stoppedEvent.WaitOne() 
    End Sub 

    Private Sub ServiceWorkerThread(ByVal state As Object) 
     ' Periodically check if the service is stopping. 
     Do While Not Me.stopping 
      ' Perform main service function here... 
      ' do anything here and wait 15 minutes before doing it again 
      Thread.Sleep(15 * 60000) ' Sleep for interval 
     Loop 

     ' Signal the stopped event. 
     Me.stoppedEvent.Set() 
    End Sub 
End Class 

，就不能停止，直到它每隔15分钟蜱和线程被唤醒。有什么方法可以捕捉服务试图停止的信号，并中断线程？

Answer 1

这是我使用的代码。在睡觉或表演时停止没有问题。

Class MyService 
    Inherits ServiceBase 

    Private Shared ReadOnly SleepPeriod As New TimeSpan(0, 15, 0) 
    Private Shared ReadOnly StopTimeout As New TimeSpan(0, 3, 0) 
    Private _TerminationHandle As New ManualResetEvent(False) 
    Private _IsRunning As Boolean = False 
    Private _ServiceThread As New Thread(Addressof ServiceMain) 

    Protected Overrides Sub OnStart(args As String()) 
     _TerminationHandle.Reset() 
     _IsRunning = True 
     _ServiceThread.Start() 
    End Sub 

    Protected Overrides Sub OnStop() 
     _TerminationHandle.Set() 
     _IsRunning = False 
     ' Terminate the thread if it doesn't stop within 3 minutes of request. 
     If Not _ServiceThread.Join(StopTimeout) Then _ServiceThread.Abort() 
     _TerminationHandle.Close() ' Can use .Dispose() if using .Net 4.0 or later. 
    End Sub 

    Private Sub ServiceMain() 
     Do 
      ' TODO: Do work here. Watch for "_IsRunning = False" to abort working when stopping. 

      ' Sleep for 15 minutes at a time. Terminate when service is stopping. 
     Loop While _IsRunning AndAlso TerminationHandle.WaitOne(SleepPeriod) 
     ' TODO: Clean up. 
    End Sub 
End Class 

Answer 2

在您当前的型号中，没有。您只使用单个线程，并且您的代码在15分钟内显式“暂停”该线程，因此在此期间任何事件都没有响应。但是，如果您对此采取稍微改进的方法，则可以改进：在不同线程中运行您的ServiceWorkerThread子，然后您的主线程可以保持对外部事件的响应。当“停止”信号到达时，如果需要，您可以强制中止工作线程。

Answer 3

看看在Thread.Interrupt方法：http://msdn.microsoft.com/en-us/library/system.threading.thread.interrupt.aspx#Y0

然而，这需要你有机会到正在运行的的Thread实例“的服务。”如果这是主线程，那么这是一个不行，但如果它是一个产生的线程，那么你可以调用中断，它会中断处于休眠/阻塞状态的Thread。