mcs/class/corlib/System.Runtime.CompilerServices/ConfiguredTaskAwaitable.cs

   1 //
   2 // ConfiguredTaskAwaitable.cs
   3 //
   4 // Authors:
   5 //      Marek Safar  <marek.safar@gmail.com>
   6 //
   7 // Copyright (C) 2011 Xamarin, Inc (http://www.xamarin.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 #if NET_4_5
  30
  31 using System.Threading;
  32 using System.Threading.Tasks;
  33 using System.Runtime.ExceptionServices;
  34
  35 namespace System.Runtime.CompilerServices
  36 {
  37         public struct ConfiguredTaskAwaitable
  38         {
  39                 public struct ConfiguredTaskAwaiter : ICriticalNotifyCompletion
  40                 {
  41                         readonly Task task;
  42                         readonly bool continueOnSourceContext;
  43
  44                         internal ConfiguredTaskAwaiter (Task task, bool continueOnSourceContext)
  45                         {
  46                                 this.task = task;
  47                                 this.continueOnSourceContext = continueOnSourceContext;
  48                         }
  49
  50                         public bool IsCompleted {
  51                                 get {
  52                                         return task.IsCompleted;
  53                                 }
  54                         }
  55
  56                         public void GetResult ()
  57                         {
  58                                 if (!task.IsCompleted)
  59                                         task.WaitCore (Timeout.Infinite, CancellationToken.None, true);
  60
  61                                 if (task.Status != TaskStatus.RanToCompletion)
  62                                         ExceptionDispatchInfo.Capture (TaskAwaiter.HandleUnexpectedTaskResult (task)).Throw ();
  63                         }
  64
  65                         public void OnCompleted (Action continuation)
  66                         {
  67                                 if (continuation == null)
  68                                         throw new ArgumentNullException ("continuation");
  69
  70                                 TaskAwaiter.HandleOnCompleted (task, continuation, continueOnSourceContext, true);
  71                         }
  72
  73                         public void UnsafeOnCompleted (Action continuation)
  74                         {
  75                                 if (continuation == null)
  76                                         throw new ArgumentNullException ("continuation");
  77
  78                                 TaskAwaiter.HandleOnCompleted (task, continuation, continueOnSourceContext, false);
  79                         }
  80                 }
  81
  82                 readonly ConfiguredTaskAwaiter awaiter;
  83
  84                 internal ConfiguredTaskAwaitable (Task task, bool continueOnSourceContext)
  85                 {
  86                         awaiter = new ConfiguredTaskAwaiter (task, continueOnSourceContext);
  87                 }
  88
  89                 public ConfiguredTaskAwaiter GetAwaiter()
  90                 {
  91                         return awaiter;
  92                 }
  93         }
  94 }
  95
  96 #endif