使用While循環的多線程處理

Question

我有一個調用4個不同服務的Azure工作者角色，我希望能夠在它自己的線程中運行每個服務，並在完成時啓動另一個迭代。由於他們都需要不同的時間來跑步，所以在我完成一次任務之前，我不想等待所有人出現。我有這個這就要求他們都在序列

public class WorkerRole : RoleEntryPoint 
{ 
    private readonly CancellationTokenSource cancellationTokenSource = new CancellationTokenSource(); 
    private readonly ManualResetEvent runCompleteEvent = new ManualResetEvent(false); 

    public override void Run() 
    { 
     Trace.TraceInformation("Polling.Worker is running"); 
     try 
     { 
      this.RunAsync(this.cancellationTokenSource.Token).Wait(); 
     } 
     finally 
     { 
      this.runCompleteEvent.Set(); 
     } 
    } 

    public override bool OnStart() 
    { 
     // Set the maximum number of concurrent connections 
     ServicePointManager.DefaultConnectionLimit = 12; 

     // For information on handling configuration changes 
     // see the MSDN topic at http://go.microsoft.com/fwlink/?LinkId=166357. 

     bool result = base.OnStart(); 

     Trace.TraceInformation("Polling.Worker has been started"); 

     return result; 
    } 

    public override void OnStop() 
    { 
     Trace.TraceInformation("Polling.Worker is stopping"); 

     this.cancellationTokenSource.Cancel(); 
     this.runCompleteEvent.WaitOne(); 

     base.OnStop(); 

     Trace.TraceInformation("Polling.Worker has stopped"); 
    } 

    private async Task RunAsync(CancellationToken cancellationToken) 
    { 
     while (!cancellationToken.IsCancellationRequested) 
     { 
      await Task.Run(() => 
      { 
       Debug.WriteLine("Starting Reddit Service"); 
       RedditService.GetObjects(); 
       Debug.WriteLine("Completed Reddit Service"); 
      }); 

      await Task.Run(() => 
      { 
       Debug.WriteLine("Starting TV Show Service"); 
       TVShowTicketService.GetObjects(); 
       Debug.WriteLine("Completed TV Show Service"); 
      }); 

      await Task.Run(() => 
      { 
       Debug.WriteLine("Starting Play By Play Service"); 
       PlayByPlayService.GetObjects(); 
       Debug.WriteLine("Completed Play By Play Service"); 
      }); 

      await Task.Run(() => 
      { 
       Debug.WriteLine("Starting Profile Service"); 
       ProfileService.Main(); 
       Debug.WriteLine("Completed Profile Service"); 
      }); 

      await Task.Delay(1000); 
     } 
    } 
} 

我知道，我在等待每一個線程，並且我希望能夠基本上都有一些，只是重複各功能一旦它是完整的，而機制，無需擔心其他線程。

Answer 1

如果我理解正確的話，你需要做的就是將您的while循環到每一個任務：

private async Task RunAsync(CancellationToken cancellationToken) 
{ 
    await Task.WhenAll(
     Task.Run(() => 
     { 
      while (!cancellationToken.IsCancellationRequested) 
      { 
       Debug.WriteLine("Starting Reddit Service"); 
       RedditService.GetObjects(); 
       Debug.WriteLine("Completed Reddit Service"); 
       await Task.Delay(1000); 
      } 
     }), 

     Task.Run(() => 
     { 
      while (!cancellationToken.IsCancellationRequested) 
      { 
       Debug.WriteLine("Starting TV Show Service"); 
       TVShowTicketService.GetObjects(); 
       Debug.WriteLine("Completed TV Show Service"); 
       await Task.Delay(1000); 
      } 
     }), 

     Task.Run(() => 
     { 
      while (!cancellationToken.IsCancellationRequested) 
      { 
       Debug.WriteLine("Starting Play By Play Service"); 
       PlayByPlayService.GetObjects(); 
       Debug.WriteLine("Completed Play By Play Service"); 
       await Task.Delay(1000); 
      } 
     }), 

     Task.Run(() => 
     { 
      while (!cancellationToken.IsCancellationRequested) 
      { 
       Debug.WriteLine("Starting Profile Service"); 
       ProfileService.Main(); 
       Debug.WriteLine("Completed Profile Service"); 
       await Task.Delay(1000); 
      } 
     })); 
} 

您可以通過一個輔助方法封裝重複的元素提高可讀性和可維護性：

private async Task RunAsync(CancellationToken cancellationToken) 
{ 
    await Task.WhenAll(
     RunServiceAsync(cancellationToken, RedditService.GetObjects, "Reddit"), 
     RunServiceAsync(cancellationToken, TVShowTicketService.GetObjects, "TV Show"), 
     RunServiceAsync(cancellationToken, PlayByPlayService.GetObjects, "Play By Play"), 
     RunServiceAsync(cancellationToken, ProfileService.Main, "Profile")); 
} 

Task RunServiceAsync(CancellationToken cancellationToken, Action service, string description) 
{ 
    return Task.Run(() => 
    { 
     while (!cancellationToken.IsCancellationRequested) 
     { 
      Debug.WriteLine("Starting " + description + " Service"); 
      service(); 
      Debug.WriteLine("Completed " + description + " Service"); 
      await Task.Delay(1000); 
     } 
    }); 
}