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c#multithreadingtask-parallel-librarytaskthreadpool
Pavan Tiwari
Pavan Tiwari

Reputation: 3187

C# Make Task Threads Foreground

I am using Task to create and perform some operations by a different thread, once the operation is done I also have called back to be called.

 System.Threading.Tasks.Task.Factory.StartNew(() =>
                   this._httpService.CreateRecord(new Uri(Configuration.Current.CreateRecordUrl), httpObj)).ContinueWith(
                   (response) =>
                   {
                       if (!response.IsFaulted)
                       {
                           if (httpObj.CallBack != null)
                           {
                               httpObj.CallBack(response.Result);
                           }
                       }
                       else {
                           this._logger.Error("There was some error which causes the task to fail");


                       }
                   });

My console application's main thread is not waiting for the Task thread to complete, because it's background thread. How can I make task thread foreground thread?

Thanks

Upvotes: 6

Views: 4210

Answers (4)

Manu Mohan
Manu Mohan

Reputation: 1784

Try creating a fresh new Thread instead of taking from the pool. For eg:

Thread t = new Thread(()=> 
{
    //all your code goes here
});
t.IsBackground = false; //by default it will be foreground. so don't need this line in your case
t.Start();

This will create a foreground thread for u and it will make sure the thread completes its execution.

Upvotes: 1

Jehof
Jehof

Reputation: 35544

You should wait for completion of the Task in your main thread.

Change your code to 

var task =  System.Threading.Tasks.Task.Factory.StartNew(() =>
    this._httpService.CreateRecord(new Uri(Configuration.Current.CreateRecordUrl), httpObj)).ContinueWith(
        (response) =>
        {
            if (!response.IsFaulted)
            {
                if (httpObj.CallBack != null)
                {
                    httpObj.CallBack(response.Result);
                }
            }
            else {
                this._logger.Error("There was some error which causes the task to field");
            }
        });
task.Wait();  // Wait till your Task has finished.

The Wait() method has some overloads to specify how long to wait. Also you have to add some exception handling if Task execution fails due to an exception of cancellation.

Upvotes: 2

Haukinger
Haukinger

Reputation: 10863

My console application's main thread is not waiting for the Task thread to complete, because it's background thread.

Your application is not waiting for the task, because you don't tell it to do so.

As others have already stated, use Wait/Result or await to wait for the task, depending on whether you're in an asynchronous context or not.

How can i make task thread foreground thread.

Most likely you don't want to do that in the first place. A background thread is a thread that terminates when all foreground threads have ended. Thread pool threads are inherently background threads, if you actually want to schedule your task to a foreground thread, that is, a thread that will keep the app process alive even if the main thread is finished, you'll have to create your own TaskScheduler. That, btw, would be a reason to use Task.Factory.StartNew. If you don't need Task.Factory.StartNew, go for Task.Run.

Upvotes: 3

RePierre
RePierre

Reputation: 9566

StartNew() method returns a Task instance. Calling Wait() method on the returned task will block the main thread until the task finishes.

static void Main(string[] args)
{
    var task = Task.Factory.StartNew(() =>
    {
        // ...
    });
    task.Wait(); // The main application thread waits here until the task returns
}

Upvotes: 4

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