mcs/class/System.Web/System.Web/TaskAsyncResult.cs

   1 //
   2 // System.Web.TaskAsyncResult.cs
   3 //
   4 // Author:
   5 //   Kornel Pal (kornelpal@gmail.com)
   6 //
   7 // Copyright (C) 2014 Kornel Pal
   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 using System.Threading;
  30 using System.Threading.Tasks;
  31
  32 namespace System.Web
  33 {
  34         sealed class TaskAsyncResult : IAsyncResult
  35         {
  36                 static readonly Action<Task, object> invokeCallback = InvokeCallback;
  37                 readonly Task task;
  38                 readonly AsyncCallback callback;
  39
  40                 public object AsyncState {
  41                         get;
  42                         private set;
  43                 }
  44
  45                 public WaitHandle AsyncWaitHandle {
  46                         get { return ((IAsyncResult) task).AsyncWaitHandle; }
  47                 }
  48
  49                 public bool CompletedSynchronously {
  50                         get;
  51                         private set;
  52                 }
  53
  54                 public bool IsCompleted {
  55                         get { return task.IsCompleted; }
  56                 }
  57
  58                 TaskAsyncResult (Task task, AsyncCallback callback, object state)
  59                 {
  60                         this.task = task;
  61                         this.callback = callback;
  62                         this.AsyncState = state;
  63                         this.CompletedSynchronously = task.IsCompleted;
  64                 }
  65
  66                 public static IAsyncResult GetAsyncResult (Task task, AsyncCallback callback, object state)
  67                 {
  68                         if (task == null)
  69                                 return null;
  70
  71                         var result = new TaskAsyncResult (task, callback, state);
  72
  73                         if (callback != null) {
  74                                 if (result.CompletedSynchronously)
  75                                         callback (result);
  76                                 else
  77                                         task.ContinueWith (invokeCallback, result);
  78                         }
  79
  80                         return result;
  81                 }
  82
  83                 public static void Wait (IAsyncResult result)
  84                 {
  85                         if (result == null)
  86                                 throw new ArgumentNullException ("result");
  87
  88                         var taskAsyncResult = result as TaskAsyncResult;
  89                         if (taskAsyncResult == null)
  90                                 throw new ArgumentException ("The provided IAsyncResult is invalid.", "result");
  91
  92                         taskAsyncResult.task.GetAwaiter ().GetResult ();
  93                 }
  94
  95                 static void InvokeCallback (Task task, object state)
  96                 {
  97                         var result = (TaskAsyncResult) state;
  98                         result.callback (result);
  99                 }
 100         }
 101 }