mcs/class/corlib/Test/System.Runtime.CompilerServices/TaskAwaiterTest.cs

   1 //
   2 // TaskAwaiterTest.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;
  32 using System.Threading;
  33 using System.Threading.Tasks;
  34 using NUnit.Framework;
  35 using System.Runtime.CompilerServices;
  36 using System.Collections.Generic;
  37 using System.Collections;
  38
  39 namespace MonoTests.System.Runtime.CompilerServices
  40 {
  41         [TestFixture]
  42         public class TaskAwaiterTest
  43         {
  44                 class Scheduler : TaskScheduler
  45                 {
  46                         string name;
  47                         int ic, qc;
  48
  49                         public Scheduler (string name)
  50                         {
  51                                 this.name = name;
  52                         }
  53
  54                         public int InlineCalls { get { return ic; } }
  55                         public int QueueCalls { get { return qc; } }
  56
  57                         protected override IEnumerable<Task> GetScheduledTasks ()
  58                         {
  59                                 throw new NotImplementedException ();
  60                         }
  61
  62                         protected override void QueueTask (Task task)
  63                         {
  64                                 Interlocked.Increment (ref qc);
  65                                 ThreadPool.QueueUserWorkItem (o => {
  66                                         TryExecuteTask (task);
  67                                 });
  68                         }
  69
  70                         protected override bool TryExecuteTaskInline (Task task, bool taskWasPreviouslyQueued)
  71                         {
  72                                 Interlocked.Increment (ref ic);
  73                                 return false;
  74                         }
  75
  76                         public override string ToString ()
  77                         {
  78                                 return "Scheduler-" + name;
  79                         }
  80                 }
  81
  82                 class SingleThreadSynchronizationContext : SynchronizationContext
  83                 {
  84                         readonly Queue _queue = new Queue ();
  85
  86                         public void RunOnCurrentThread ()
  87                         {
  88                                 while (_queue.Count != 0) {
  89                                         var workItem = (KeyValuePair<SendOrPostCallback, object>) _queue.Dequeue ();
  90                                         workItem.Key (workItem.Value);
  91                                 }
  92                         }
  93
  94                         public override void Post (SendOrPostCallback d, object state)
  95                         {
  96                                 if (d == null) {
  97                                         throw new ArgumentNullException ("d");
  98                                 }
  99
 100                                 _queue.Enqueue (new KeyValuePair<SendOrPostCallback, object> (d, state));
 101                         }
 102
 103                         public override void Send (SendOrPostCallback d, object state)
 104                         {
 105                                 throw new NotSupportedException ("Synchronously sending is not supported.");
 106                         }
 107                 }
 108
 109                 string progress;
 110                 SynchronizationContext sc;
 111                 ManualResetEvent mre;
 112
 113                 [SetUp]
 114                 public void Setup ()
 115                 {
 116                         sc = SynchronizationContext.Current;
 117                 }
 118
 119                 [TearDown]
 120                 public void TearDown ()
 121                 {
 122                         SynchronizationContext.SetSynchronizationContext (sc);
 123                 }
 124
 125                 [Test]
 126                 public void GetResultFaulted ()
 127                 {
 128                         TaskAwaiter awaiter;
 129
 130                         var task = new Task (() => { throw new ApplicationException (); });
 131                         awaiter = task.GetAwaiter ();
 132                         task.RunSynchronously (TaskScheduler.Current);
 133
 134
 135                         Assert.IsTrue (awaiter.IsCompleted);
 136
 137                         try {
 138                                 awaiter.GetResult ();
 139                                 Assert.Fail ();
 140                         } catch (ApplicationException) {
 141                         }
 142                 }
 143
 144                 [Test]
 145                 public void GetResultCanceled ()
 146                 {
 147                         TaskAwaiter awaiter;
 148
 149                         var token = new CancellationToken (true);
 150                         var task = new Task (() => { }, token);
 151                         awaiter = task.GetAwaiter ();
 152
 153                         try {
 154                                 awaiter.GetResult ();
 155                                 Assert.Fail ();
 156                         } catch (TaskCanceledException) {
 157                         }
 158                 }
 159
 160                 [Test]
 161                 public void GetResultWaitOnCompletion ()
 162                 {
 163                         TaskAwaiter awaiter;
 164
 165                         var task = Task.Delay (30);
 166                         awaiter = task.GetAwaiter ();
 167
 168                         awaiter.GetResult ();
 169                         Assert.AreEqual (TaskStatus.RanToCompletion, task.Status);
 170                 }
 171
 172                 [Test]
 173                 public void CustomScheduler ()
 174                 {
 175                         // some test runners (e.g. Touch.Unit) will execute this on the main thread and that would lock them
 176                         if (!Thread.CurrentThread.IsBackground)
 177                                 Assert.Ignore ("Current thread is not running in the background.");
 178
 179                         var a = new Scheduler ("a");
 180                         var b = new Scheduler ("b");
 181
 182                         var t = TestCS (a, b);
 183                         Assert.IsTrue (t.Wait (3000), "#0");
 184                         Assert.AreEqual (0, t.Result, "#1");
 185                         Assert.AreEqual (0, b.InlineCalls, "#2b");
 186                         Assert.IsTrue (a.QueueCalls == 1 || a.QueueCalls == 2, "#3a");
 187                         Assert.AreEqual (1, b.QueueCalls, "#3b");
 188                 }
 189
 190                 static async Task<int> TestCS (TaskScheduler schedulerA, TaskScheduler schedulerB)
 191                 {
 192                         var res = await Task.Factory.StartNew (async () => {
 193                                 if (TaskScheduler.Current != schedulerA)
 194                                         return 1;
 195
 196                                 await Task.Factory.StartNew (
 197                                         () => {
 198                                                 if (TaskScheduler.Current != schedulerB)
 199                                                         return 2;
 200
 201                                                 return 0;
 202                                         }, CancellationToken.None, TaskCreationOptions.None, schedulerB);
 203
 204                                 if (TaskScheduler.Current != schedulerA)
 205                                         return 3;
 206
 207                                 return 0;
 208                         }, CancellationToken.None, TaskCreationOptions.None, schedulerA);
 209
 210                         return res.Result;
 211                 }
 212
 213                 [Test]
 214                 public void FinishedTaskOnCompleted ()
 215                 {
 216                         var mres = new ManualResetEvent (false);
 217                         var mres2 = new ManualResetEvent (false);
 218
 219                         var tcs = new TaskCompletionSource<object> ();
 220                         tcs.SetResult (null);
 221                         var task = tcs.Task;
 222
 223                         var awaiter = task.GetAwaiter ();
 224                         Assert.IsTrue (awaiter.IsCompleted, "#1");
 225
 226                         awaiter.OnCompleted(() => {
 227                                 if (mres.WaitOne (1000))
 228                                         mres2.Set ();
 229                         });
 230
 231                         mres.Set ();
 232                         // this will only terminate correctly if the test was not executed from the main thread
 233                         // e.g. Touch.Unit defaults to run tests on the main thread and this will return false
 234                         Assert.AreEqual (Thread.CurrentThread.IsBackground, mres2.WaitOne (2000), "#2");;
 235                 }
 236
 237                 [Test]
 238                 public void CompletionOnSameCustomSynchronizationContext ()
 239                 {
 240                         progress = "";
 241                         var syncContext = new SingleThreadSynchronizationContext ();
 242                         SynchronizationContext.SetSynchronizationContext (syncContext);
 243
 244                         syncContext.Post (delegate {
 245                                 Go (syncContext);
 246                         }, null);
 247
 248                         // Custom message loop
 249                         var cts = new CancellationTokenSource ();
 250                         cts.CancelAfter (5000);
 251                         while (progress.Length != 3 && !cts.IsCancellationRequested) {
 252                                 syncContext.RunOnCurrentThread ();
 253                                 Thread.Sleep (0);
 254                         }
 255
 256                         Assert.AreEqual ("123", progress);
 257                 }
 258
 259                 async void Go (SynchronizationContext ctx)
 260                 {
 261                         await Wait (ctx);
 262
 263                         progress += "2";
 264                 }
 265
 266                 async Task Wait (SynchronizationContext ctx)
 267                 {
 268                         await Task.Delay (10); // Force block suspend/return
 269
 270                         ctx.Post (l => progress += "3", null);
 271
 272                         progress += "1";
 273
 274                         // Exiting same context - no need to post continuation
 275                 }
 276
 277                 [Test]
 278                 public void CompletionOnDifferentCustomSynchronizationContext ()
 279                 {
 280                         mre = new ManualResetEvent (false);
 281                         progress = "";
 282                         var syncContext = new SingleThreadSynchronizationContext ();
 283                         SynchronizationContext.SetSynchronizationContext (syncContext);
 284
 285                         syncContext.Post (delegate {
 286                                 Task t = new Task (delegate() { });
 287                                 Go2 (syncContext, t);
 288                                 t.Start ();
 289                         }, null);
 290
 291                         // Custom message loop
 292                         var cts = new CancellationTokenSource ();
 293                         cts.CancelAfter (5000);
 294                         while (progress.Length != 3 && !cts.IsCancellationRequested) {
 295                                 syncContext.RunOnCurrentThread ();
 296                                 Thread.Sleep (0);
 297                         }
 298
 299                         Assert.AreEqual ("13xa2", progress);
 300                 }
 301
 302                 async void Go2 (SynchronizationContext ctx, Task t)
 303                 {
 304                         await Wait2 (ctx, t);
 305
 306                         progress += "a";
 307
 308                         if (mre.WaitOne (5000))
 309                                 progress += "2";
 310                         else
 311                                 progress += "b";
 312                 }
 313
 314                 async Task Wait2 (SynchronizationContext ctx, Task t)
 315                 {
 316                         await t; // Force block suspend/return
 317
 318                         ctx.Post (l => {
 319                                 progress += "3";
 320                                 mre.Set ();
 321                                 progress += "x";
 322                         }, null);
 323
 324                         progress += "1";
 325
 326                         SynchronizationContext.SetSynchronizationContext (null);
 327                 }
 328         }
 329 }
 330
 331 #endif