mcs/tests/test-async-55.cs

   1 using System;
   2 using System.Threading;
   3 using System.Threading.Tasks;
   4
   5 class MyContext : SynchronizationContext
   6 {
   7         public override void Post (SendOrPostCallback d, object state)
   8         {
   9                 base.Post (d, state);
  10         }
  11
  12         public override void Send (SendOrPostCallback d, object state)
  13         {
  14                 base.Send (d, state);
  15         }
  16 }
  17
  18 class X
  19 {
  20         static TaskCompletionSource<bool> tcs;
  21         static ManualResetEvent mre, mre2;
  22         static int main_thread_id;
  23
  24         public static int Main ()
  25         {
  26                 main_thread_id = Thread.CurrentThread.ManagedThreadId;
  27                 Console.WriteLine ("{0}:Main start", main_thread_id);
  28
  29                 mre = new ManualResetEvent (false);
  30                 mre2 = new ManualResetEvent (false);
  31                 tcs = new TaskCompletionSource<bool> ();
  32
  33                 Task.Factory.StartNew (new Func<Task> (ExecuteAsync), new CancellationToken (), TaskCreationOptions.LongRunning, TaskScheduler.Default);
  34
  35                 if (!mre.WaitOne (1000))
  36                         return 1;
  37
  38                 // Have to wait little bit longer for await not to take quick path
  39                 Thread.Sleep (10);
  40
  41                 Console.WriteLine ("{0}:Main Set Result", Thread.CurrentThread.ManagedThreadId);
  42
  43                 SynchronizationContext.SetSynchronizationContext (new MyContext ());
  44
  45                 tcs.SetResult (true);
  46
  47                 if (!mre2.WaitOne (1000))
  48                         return 2;
  49
  50                 Console.WriteLine ("ok");
  51                 return 0;
  52         }
  53
  54         static async Task ExecuteAsync ()
  55         {
  56                 var t = Thread.CurrentThread;
  57                 Console.WriteLine ("{0} - started ", t.ManagedThreadId);
  58
  59                 mre.Set ();
  60
  61                 await tcs.Task;
  62                 t = Thread.CurrentThread;
  63                 Console.WriteLine ("{0} - resumed ", t.ManagedThreadId);
  64
  65                 //
  66                 // Continuation cannot resume on main thread because it has synchronization context set
  67                 //
  68                 if (main_thread_id != Thread.CurrentThread.ManagedThreadId)
  69                         mre2.Set ();
  70         }
  71 }