Handle task cancellation in the .NET client

#2178
SignalR · Jun 29, 2013 · 6a04fb5 · 6a04fb5
1 parent f9d5662
commit 6a04fb5
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Showing 6 changed files with 98 additions and 7 deletions.
diff --git a/src/Microsoft.AspNet.SignalR.Client.WinRT/Resources.resw b/src/Microsoft.AspNet.SignalR.Client.WinRT/Resources.resw
@@ -147,6 +147,9 @@
   <data name="Error_StartMustBeCalledBeforeDataCanBeSent" xml:space="preserve">
     <value>The Start method must be called before data can be sent.</value>
   </data>
+  <data name="Error_TaskCancelledException" xml:space="preserve">
+    <value>Request failed - task cancelled.</value>
+  </data>
   <data name="Error_TransportFailedToConnect" xml:space="preserve">
     <value>Transport failed trying to connect.</value>
   </data>

diff --git a/src/Microsoft.AspNet.SignalR.Client/Resources.Designer.cs b/src/Microsoft.AspNet.SignalR.Client/Resources.Designer.cs
diff --git a/src/Microsoft.AspNet.SignalR.Client/Resources.resx b/src/Microsoft.AspNet.SignalR.Client/Resources.resx
@@ -147,6 +147,9 @@
   <data name="Error_StartMustBeCalledBeforeDataCanBeSent" xml:space="preserve">
     <value>The Start method must be called before data can be sent.</value>
   </data>
+  <data name="Error_TaskCancelledException" xml:space="preserve">
+    <value>Request failed - task cancelled.</value>
+  </data>
   <data name="Error_TransportFailedToConnect" xml:space="preserve">
     <value>Transport failed trying to connect.</value>
   </data>

diff --git a/src/Microsoft.AspNet.SignalR.Client/Transports/LongPolling/PollingRequestHandler.cs b/src/Microsoft.AspNet.SignalR.Client/Transports/LongPolling/PollingRequestHandler.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.md in the project root for license information.
 
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNet.SignalR.Client.Http;
@@ -79,7 +80,8 @@ public void Start()
             }
         }
 
-        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Exceptions are flowed back to user.")]
+        [SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Exceptions are flowed back to user.")]
+        [SuppressMessage("Microsoft.Usage", "CA2201:ExceptionNotSufficientlySpecific", Justification = "Limited information about cancellation")]
         private void Poll()
         {
             // This is to ensure that we do not accidently fire off another poll after being told to stop
@@ -108,9 +110,16 @@ private void Poll()
                     var next = TaskAsyncHelper.Empty;
                     Exception exception = null;
 
-                    if (task.IsFaulted)
+                    if (task.IsFaulted || task.IsCanceled)
                     {
-                        exception = task.Exception.Unwrap();
+                        if (task.IsCanceled)
+                        {
+                            exception = new Exception(Resources.Error_TaskCancelledException);
+                        }
+                        else
+                        {
+                            exception = task.Exception.Unwrap();
+                        }
 
                         OnError(exception);
                     }

diff --git a/src/Microsoft.AspNet.SignalR.Client/Transports/ServerSentEventsTransport.cs b/src/Microsoft.AspNet.SignalR.Client/Transports/ServerSentEventsTransport.cs
@@ -79,8 +79,14 @@ private void Reconnect(IConnection connection, string data, CancellationToken di
             });
         }
 
+        public void OpenConnection(IConnection connection, Action<Exception> errorCallback)
+        {
+            OpenConnection(connection, null, CancellationToken.None, () => { }, errorCallback);
+        }
+
         [SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity", Justification = "We will refactor later.")]
         [SuppressMessage("Microsoft.Maintainability", "CA1506:AvoidExcessiveClassCoupling", Justification = "We will refactor later.")]
+        [SuppressMessage("Microsoft.Usage", "CA2201:ExceptionNotSufficientlySpecific", Justification = "Limited information about cancellation")]
         private void OpenConnection(IConnection connection,
                                     string data,
                                     CancellationToken disconnectToken,
@@ -108,9 +114,19 @@ private void Reconnect(IConnection connection, string data, CancellationToken di
 
             }, isLongRunning: true).ContinueWith(task =>
             {
-                if (task.IsFaulted)
+                if (task.IsFaulted || task.IsCanceled)
                 {
-                    Exception exception = task.Exception.Unwrap();
+                    Exception exception;
+
+                    if (task.IsCanceled)
+                    {
+                        exception = new Exception(Resources.Error_TaskCancelledException);
+                    }
+                    else
+                    {
+                        exception = task.Exception.Unwrap();
+                    }
+
                     if (!ExceptionHelper.IsRequestAborted(exception))
                     {
                         if (errorCallback != null)

diff --git a/tests/Microsoft.AspNet.SignalR.Tests/Client/TransportFacts.cs b/tests/Microsoft.AspNet.SignalR.Tests/Client/TransportFacts.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.AspNet.SignalR.Client;
 using Microsoft.AspNet.SignalR.Client.Http;
 using Microsoft.AspNet.SignalR.Client.Transports;
@@ -84,6 +85,56 @@ public void ProcessResponseCapturesOnReceivedExceptions()
             connection.VerifyAll();
         }
 
+        [Fact]
+        public void CancelledTaskHandledinServerSentEvents()
+        {
+            var tcs = new TaskCompletionSource<IResponse>();
+            var wh = new TaskCompletionSource<Exception>();
+
+            tcs.TrySetCanceled();
+
+            var httpClient = new Mock<Microsoft.AspNet.SignalR.Client.Http.IHttpClient>();
+            var connection = new Mock<Microsoft.AspNet.SignalR.Client.IConnection>();
+
+            httpClient.Setup(c => c.Get(It.IsAny<string>(),
+                It.IsAny<Action<Client.Http.IRequest>>(), It.IsAny<bool>()))
+                .Returns(tcs.Task);
+
+            connection.SetupGet(c => c.ConnectionToken).Returns("foo");
+
+            var sse = new ServerSentEventsTransport(httpClient.Object);
+            sse.OpenConnection(connection.Object, (ex) =>
+            {
+                wh.TrySetResult(ex);
+            });
+
+            Assert.True(wh.Task.Wait(TimeSpan.FromSeconds(5)));
+            Assert.Equal("Request failed - task cancelled.", wh.Task.Result.Message);
+        }
+
+        [Fact]
+        public void CancelledTaskHandledinLongPolling()
+        {
+            var tcs = new TaskCompletionSource<IResponse>();
+            var wh = new TaskCompletionSource<Exception>();
+
+            tcs.TrySetCanceled();
+
+            var httpClient = new Mock<Microsoft.AspNet.SignalR.Client.Http.IHttpClient>();
+
+            httpClient.Setup(c => c.Post(It.IsAny<string>(),
+                It.IsAny<Action<Client.Http.IRequest>>(), It.IsAny<IDictionary<string, string>>(), It.IsAny<bool>()))
+                .Returns(tcs.Task);
+
+            var pollingHandler = new PollingRequestHandler(httpClient.Object);
+            pollingHandler.Start();
+
+            pollingHandler.OnError += (ex) => { wh.TrySetResult(ex); };
+
+            Assert.True(wh.Task.Wait(TimeSpan.FromSeconds(5)));
+            Assert.Equal("Request failed - task cancelled.", wh.Task.Result.Message);
+        }
+
         [Fact]
         public void SendCatchesOnReceivedExceptions()
         {
@@ -106,7 +157,7 @@ public void SendCatchesOnReceivedExceptions()
 
                     httpClient.Setup(h => h.Post(It.IsAny<string>(),
                                                  It.IsAny<Action<Client.Http.IRequest>>(),
-                                                 It.IsAny<IDictionary<string, string>>(),false))
+                                                 It.IsAny<IDictionary<string, string>>(), false))
                               .Returns(TaskAsyncHelper.FromResult(response.Object));
 
                     connection.Setup(c => c.Trace(TraceLevels.Messages, It.IsAny<string>(), It.IsAny<object[]>()));