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