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

   1 //
   2 // ConfiguredTaskAwaitable_T.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.Tasks;
  32 using System.Runtime.ExceptionServices;
  33
  34 namespace System.Runtime.CompilerServices
  35 {
  36         public struct ConfiguredTaskAwaitable<TResult>
  37         {
  38                 public struct ConfiguredTaskAwaiter : ICriticalNotifyCompletion
  39                 {
  40                         readonly Task<TResult> task;
  41                         readonly bool continueOnSourceContext;
  42
  43                         internal ConfiguredTaskAwaiter (Task<TResult> task, bool continueOnSourceContext)
  44                         {
  45                                 this.task = task;
  46                                 this.continueOnSourceContext = continueOnSourceContext;
  47                         }
  48
  49                         public bool IsCompleted {
  50                                 get {
  51                                         return task.IsCompleted;
  52                                 }
  53                         }
  54
  55                         public TResult GetResult ()
  56                         {
  57                                 if (task.Status != TaskStatus.RanToCompletion)
  58                                         ExceptionDispatchInfo.Capture (TaskAwaiter.HandleUnexpectedTaskResult (task)).Throw ();
  59
  60                                 return task.Result;
  61                         }
  62
  63                         public void OnCompleted (Action continuation)
  64                         {
  65                                 if (continuation == null)
  66                                         throw new ArgumentNullException ("continuation");
  67
  68                                 TaskAwaiter.HandleOnCompleted (task, continuation, continueOnSourceContext, true);
  69                         }
  70
  71                         public void UnsafeOnCompleted (Action continuation)
  72                         {
  73                                 if (continuation == null)
  74                                         throw new ArgumentNullException ("continuation");
  75
  76                                 TaskAwaiter.HandleOnCompleted (task, continuation, continueOnSourceContext, false);
  77                         }
  78                 }
  79
  80                 readonly ConfiguredTaskAwaiter awaiter;
  81
  82                 internal ConfiguredTaskAwaitable (Task<TResult> task, bool continueOnSourceContext)
  83                 {
  84                         awaiter = new ConfiguredTaskAwaiter (task, continueOnSourceContext);
  85                 }
  86
  87                 public ConfiguredTaskAwaiter GetAwaiter()
  88                 {
  89                         return awaiter;
  90                 }
  91         }
  92 }
  93
  94 #endif