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 using System.Collections.Concurrent;
  39
  40 namespace MonoTests.System.Runtime.CompilerServices
  41 {
  42         [TestFixture]
  43         public class TaskAwaiterTest
  44         {
  45                 class Scheduler : TaskScheduler
  46                 {
  47                         string name;
  48                         int ic, qc;
  49
  50                         public Scheduler (string name)
  51                         {
  52                                 this.name = name;
  53                         }
  54
  55                         public int InlineCalls { get { return ic; } }
  56                         public int QueueCalls { get { return qc; } }
  57
  58                         protected override IEnumerable<Task> GetScheduledTasks ()
  59                         {
  60                                 throw new NotImplementedException ();
  61                         }
  62
  63                         protected override void QueueTask (Task task)
  64                         {
  65                                 Interlocked.Increment (ref qc);
  66                                 ThreadPool.QueueUserWorkItem (o => {
  67                                         TryExecuteTask (task);
  68                                 });
  69                         }
  70
  71                         protected override bool TryExecuteTaskInline (Task task, bool taskWasPreviouslyQueued)
  72                         {
  73                                 Interlocked.Increment (ref ic);
  74                                 return false;
  75                         }
  76
  77                         public override string ToString ()
  78                         {
  79                                 return "Scheduler-" + name;
  80                         }
  81                 }
  82
  83                 class SingleThreadSynchronizationContext : SynchronizationContext
  84                 {
  85                         readonly Queue _queue = new Queue ();
  86
  87                         public void RunOnCurrentThread ()
  88                         {
  89                                 while (_queue.Count != 0) {
  90                                         var workItem = (KeyValuePair<SendOrPostCallback, object>) _queue.Dequeue ();
  91                                         workItem.Key (workItem.Value);
  92                                 }
  93                         }
  94
  95                         public override void Post (SendOrPostCallback d, object state)
  96                         {
  97                                 if (d == null) {
  98                                         throw new ArgumentNullException ("d");
  99                                 }
 100
 101                                 _queue.Enqueue (new KeyValuePair<SendOrPostCallback, object> (d, state));
 102                         }
 103
 104                         public override void Send (SendOrPostCallback d, object state)
 105                         {
 106                                 throw new NotSupportedException ("Synchronously sending is not supported.");
 107                         }
 108                 }
 109
 110                 class NestedSynchronizationContext : SynchronizationContext
 111                 {
 112                         Thread thread;
 113                         readonly ConcurrentQueue<Tuple<SendOrPostCallback, object, ExecutionContext>> workQueue = new ConcurrentQueue<Tuple<SendOrPostCallback, object, ExecutionContext>> ();
 114                         readonly AutoResetEvent workReady = new AutoResetEvent (false);
 115
 116                         public NestedSynchronizationContext ()
 117                         {
 118                                 thread = new Thread (WorkerThreadProc) { IsBackground = true };
 119                                 thread.Start ();
 120                         }
 121
 122                         public override void Post (SendOrPostCallback d, object state)
 123                         {
 124                                 var context = ExecutionContext.Capture ();
 125                                 workQueue.Enqueue (Tuple.Create (d, state, context));
 126                                 workReady.Set ();
 127                         }
 128
 129                         void WorkerThreadProc ()
 130                         {
 131                                 if (!workReady.WaitOne (10000))
 132                                         return;
 133
 134                                 Tuple<SendOrPostCallback, object, ExecutionContext> work;
 135
 136                                 while (workQueue.TryDequeue (out work)) {
 137                                         ExecutionContext.Run (work.Item3, _ => {
 138                                                 var oldSyncContext = SynchronizationContext.Current;
 139                                                 SynchronizationContext.SetSynchronizationContext (this);
 140                                                 work.Item1 (_);
 141                                                 SynchronizationContext.SetSynchronizationContext (oldSyncContext);
 142                                         }, work.Item2);
 143                                 }
 144                         }
 145                 }
 146
 147                 string progress;
 148                 SynchronizationContext sc;
 149                 ManualResetEvent mre;
 150
 151                 [SetUp]
 152                 public void Setup ()
 153                 {
 154                         sc = SynchronizationContext.Current;
 155                 }
 156
 157                 [TearDown]
 158                 public void TearDown ()
 159                 {
 160                         SynchronizationContext.SetSynchronizationContext (sc);
 161                 }
 162
 163                 [Test]
 164                 public void GetResultFaulted ()
 165                 {
 166                         TaskAwaiter awaiter;
 167
 168                         var task = new Task (() => { throw new ApplicationException (); });
 169                         awaiter = task.GetAwaiter ();
 170                         task.RunSynchronously (TaskScheduler.Current);
 171
 172
 173                         Assert.IsTrue (awaiter.IsCompleted);
 174
 175                         try {
 176                                 awaiter.GetResult ();
 177                                 Assert.Fail ();
 178                         } catch (ApplicationException) {
 179                         }
 180                 }
 181
 182                 [Test]
 183                 public void GetResultCanceled ()
 184                 {
 185                         TaskAwaiter awaiter;
 186
 187                         var token = new CancellationToken (true);
 188                         var task = new Task (() => { }, token);
 189                         awaiter = task.GetAwaiter ();
 190
 191                         try {
 192                                 awaiter.GetResult ();
 193                                 Assert.Fail ();
 194                         } catch (TaskCanceledException) {
 195                         }
 196                 }
 197
 198                 [Test]
 199                 public void GetResultWaitOnCompletion ()
 200                 {
 201                         TaskAwaiter awaiter;
 202
 203                         var task = Task.Delay (30);
 204                         awaiter = task.GetAwaiter ();
 205
 206                         awaiter.GetResult ();
 207                         Assert.AreEqual (TaskStatus.RanToCompletion, task.Status);
 208                 }
 209
 210                 [Test]
 211                 public void CustomScheduler ()
 212                 {
 213                         // some test runners (e.g. Touch.Unit) will execute this on the main thread and that would lock them
 214                         if (!Thread.CurrentThread.IsBackground)
 215                                 Assert.Ignore ("Current thread is not running in the background.");
 216
 217                         var a = new Scheduler ("a");
 218                         var b = new Scheduler ("b");
 219
 220                         var t = TestCS (a, b);
 221                         Assert.IsTrue (t.Wait (3000), "#0");
 222                         Assert.AreEqual (0, t.Result, "#1");
 223                         Assert.AreEqual (0, b.InlineCalls, "#2b");
 224                         Assert.IsTrue (a.QueueCalls == 1 || a.QueueCalls == 2, "#3a");
 225                         Assert.AreEqual (1, b.QueueCalls, "#3b");
 226                 }
 227
 228                 static async Task<int> TestCS (TaskScheduler schedulerA, TaskScheduler schedulerB)
 229                 {
 230                         var res = await Task.Factory.StartNew (async () => {
 231                                 if (TaskScheduler.Current != schedulerA)
 232                                         return 1;
 233
 234                                 await Task.Factory.StartNew (
 235                                         () => {
 236                                                 if (TaskScheduler.Current != schedulerB)
 237                                                         return 2;
 238
 239                                                 return 0;
 240                                         }, CancellationToken.None, TaskCreationOptions.None, schedulerB);
 241
 242                                 if (TaskScheduler.Current != schedulerA)
 243                                         return 3;
 244
 245                                 return 0;
 246                         }, CancellationToken.None, TaskCreationOptions.None, schedulerA);
 247
 248                         return res.Result;
 249                 }
 250
 251                 [Test]
 252                 public void FinishedTaskOnCompleted ()
 253                 {
 254                         var mres = new ManualResetEvent (false);
 255                         var mres2 = new ManualResetEvent (false);
 256
 257                         var tcs = new TaskCompletionSource<object> ();
 258                         tcs.SetResult (null);
 259                         var task = tcs.Task;
 260
 261                         var awaiter = task.GetAwaiter ();
 262                         Assert.IsTrue (awaiter.IsCompleted, "#1");
 263
 264                         awaiter.OnCompleted(() => {
 265                                 if (mres.WaitOne (1000))
 266                                         mres2.Set ();
 267                         });
 268
 269                         mres.Set ();
 270                         // this will only terminate correctly if the test was not executed from the main thread
 271                         // e.g. Touch.Unit defaults to run tests on the main thread and this will return false
 272                         Assert.AreEqual (Thread.CurrentThread.IsBackground, mres2.WaitOne (2000), "#2");;
 273                 }
 274
 275                 [Test]
 276                 public void CompletionOnSameCustomSynchronizationContext ()
 277                 {
 278                         progress = "";
 279                         var syncContext = new SingleThreadSynchronizationContext ();
 280                         SynchronizationContext.SetSynchronizationContext (syncContext);
 281
 282                         syncContext.Post (delegate {
 283                                 Go (syncContext);
 284                         }, null);
 285
 286                         // Custom message loop
 287                         var cts = new CancellationTokenSource ();
 288                         cts.CancelAfter (5000);
 289                         while (progress.Length != 3 && !cts.IsCancellationRequested) {
 290                                 syncContext.RunOnCurrentThread ();
 291                                 Thread.Sleep (0);
 292                         }
 293
 294                         Assert.AreEqual ("123", progress);
 295                 }
 296
 297                 async void Go (SynchronizationContext ctx)
 298                 {
 299                         await Wait (ctx);
 300
 301                         progress += "2";
 302                 }
 303
 304                 async Task Wait (SynchronizationContext ctx)
 305                 {
 306                         await Task.Delay (10); // Force block suspend/return
 307
 308                         ctx.Post (l => progress += "3", null);
 309
 310                         progress += "1";
 311
 312                         // Exiting same context - no need to post continuation
 313                 }
 314
 315                 [Test]
 316                 public void CompletionOnDifferentCustomSynchronizationContext ()
 317                 {
 318                         mre = new ManualResetEvent (false);
 319                         progress = "";
 320                         var syncContext = new SingleThreadSynchronizationContext ();
 321                         SynchronizationContext.SetSynchronizationContext (syncContext);
 322
 323                         syncContext.Post (delegate {
 324                                 Task t = new Task (delegate() { });
 325                                 Go2 (syncContext, t);
 326                                 t.Start ();
 327                         }, null);
 328
 329                         // Custom message loop
 330                         var cts = new CancellationTokenSource ();
 331                         cts.CancelAfter (5000);
 332                         while (progress.Length != 3 && !cts.IsCancellationRequested) {
 333                                 syncContext.RunOnCurrentThread ();
 334                                 Thread.Sleep (0);
 335                         }
 336
 337                         Assert.AreEqual ("13xa2", progress);
 338                 }
 339
 340                 async void Go2 (SynchronizationContext ctx, Task t)
 341                 {
 342                         await Wait2 (ctx, t);
 343
 344                         progress += "a";
 345
 346                         if (mre.WaitOne (5000))
 347                                 progress += "2";
 348                         else
 349                                 progress += "b";
 350                 }
 351
 352                 async Task Wait2 (SynchronizationContext ctx, Task t)
 353                 {
 354                         await t; // Force block suspend/return
 355
 356                         ctx.Post (l => {
 357                                 progress += "3";
 358                                 mre.Set ();
 359                                 progress += "x";
 360                         }, null);
 361
 362                         progress += "1";
 363
 364                         SynchronizationContext.SetSynchronizationContext (null);
 365                 }
 366
 367                 [Test]
 368                 public void NestedLeakingSynchronizationContext ()
 369                 {
 370                         var sc = SynchronizationContext.Current;
 371                         if (sc == null)
 372                                 Assert.IsTrue (NestedLeakingSynchronizationContext_MainAsync (sc).Wait (5000), "#1");
 373                         else
 374                                 Assert.Ignore ("NestedSynchronizationContext may never complete on custom context");
 375                 }
 376
 377                 static async Task NestedLeakingSynchronizationContext_MainAsync (SynchronizationContext sc)
 378                 {
 379                         Assert.AreSame (sc, SynchronizationContext.Current, "#1");
 380                         await NestedLeakingSynchronizationContext_DoWorkAsync ();
 381                         Assert.AreSame (sc, SynchronizationContext.Current, "#2");
 382                 }
 383
 384                 static async Task NestedLeakingSynchronizationContext_DoWorkAsync ()
 385                 {
 386                         var sc = new NestedSynchronizationContext ();
 387                         SynchronizationContext.SetSynchronizationContext (sc);
 388
 389                         Assert.AreSame (sc, SynchronizationContext.Current);
 390                         await Task.Yield ();
 391                         Assert.AreSame (sc, SynchronizationContext.Current);
 392                 }
 393         }
 394 }
 395
 396 #endif