TaskStatus Enumeration

 

Represents the current stage in the lifecycle of a Task.

Namespace:   System.Threading.Tasks
Assembly:  mscorlib (in mscorlib.dll)

public enum TaskStatus

Member nameDescription
Canceled

The task acknowledged cancellation by throwing an OperationCanceledException with its own CancellationToken while the token was in signaled state, or the task's CancellationToken was already signaled before the task started executing. For more information, see Task Cancellation.

Created

The task has been initialized but has not yet been scheduled.

Faulted

The task completed due to an unhandled exception.

RanToCompletion

The task completed execution successfully.

Running

The task is running but has not yet completed.

WaitingForActivation

The task is waiting to be activated and scheduled internally by the .NET Framework infrastructure.

WaitingForChildrenToComplete

The task has finished executing and is implicitly waiting for attached child tasks to complete.

WaitingToRun

The task has been scheduled for execution but has not yet begun executing.

The Task.Status property returns a member of the TaskStatus enumeration to indicate the task's current status.

The following example creates 20 tasks that will loop until a counter is incremented to a value of 2 million. When the first 10 tasks reach 2 million, the cancellation token is cancelled, and any tasks whose counters have not reached 2 million are cancelled. The example then examines the Task.Status property of each task to indicate whether the task has completed successfully or been cancelled. For those that have completed, it displays the value returned by the task.

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

public class Example
{
   public static void Main()
   {
      var tasks = new List<Task<int>>();
      var source = new CancellationTokenSource();
      var token = source.Token;
      int completedIterations = 0;

      for (int n = 0; n <= 19; n++)
         tasks.Add(Task.Run( () => { int iterations = 0;
                                     for (int ctr = 1; ctr <= 2000000; ctr++) {
                                         token.ThrowIfCancellationRequested();
                                         iterations++;
                                     }
                                     Interlocked.Increment(ref completedIterations);
                                     if (completedIterations >= 10)
                                        source.Cancel();
                                     return iterations; }, token));

      Console.WriteLine("Waiting for the first 10 tasks to complete...\n");
      try  {
         Task.WaitAll(tasks.ToArray());
      }
      catch (AggregateException) {
         Console.WriteLine("Status of tasks:\n");
         Console.WriteLine("{0,10} {1,20} {2,14:N0}", "Task Id",
                           "Status", "Iterations");
         foreach (var t in tasks)
            Console.WriteLine("{0,10} {1,20} {2,14}",
                              t.Id, t.Status,
                              t.Status != TaskStatus.Canceled ? t.Result.ToString("N0") : "n/a");
      }
   }
}
// The example displays output like the following:
//    Waiting for the first 10 tasks to complete...
//    Status of tasks:
//
//       Task Id               Status     Iterations
//             1      RanToCompletion      2,000,000
//             2      RanToCompletion      2,000,000
//             3      RanToCompletion      2,000,000
//             4      RanToCompletion      2,000,000
//             5      RanToCompletion      2,000,000
//             6      RanToCompletion      2,000,000
//             7      RanToCompletion      2,000,000
//             8      RanToCompletion      2,000,000
//             9      RanToCompletion      2,000,000
//            10             Canceled            n/a
//            11             Canceled            n/a
//            12             Canceled            n/a
//            13             Canceled            n/a
//            14             Canceled            n/a
//            15             Canceled            n/a
//            16      RanToCompletion      2,000,000
//            17             Canceled            n/a
//            18             Canceled            n/a
//            19             Canceled            n/a
//            20             Canceled            n/a

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 5.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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