Added various catches to prevent unobserved task exceptions, tried to prevent the exceptions by checking web-socket state (#4052)

Author: randyridge

src/HotChocolate/AspNetCore/src/AspNetCore/Subscriptions/DefaultMessagePipeline.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Net.WebSockets;
 using System.Threading;
 using System.Threading.Tasks;
 using HotChocolate.AspNetCore.Subscriptions.Messages;
@@ -30,15 +31,22 @@ public async Task ProcessAsync(
             ReadOnlySequence<byte> slice,
             CancellationToken cancellationToken)
         {
-            if (TryParseMessage(slice, out OperationMessage? message))
+            try
             {
-                await HandleMessageAsync(connection, message, cancellationToken);
+                if (TryParseMessage(slice, out OperationMessage? message))
+                {
+                    await HandleMessageAsync(connection, message, cancellationToken);
+                }
+                else
+                {
+                    await connection.SendAsync(
+                        KeepConnectionAliveMessage.Default,
+                        CancellationToken.None);
+                }
             }
-            else
+            catch (WebSocketException)
             {
-                await connection.SendAsync(
-                    KeepConnectionAliveMessage.Default,
-                    CancellationToken.None);
+                // we will just stop receiving
             }
         }
 

src/HotChocolate/AspNetCore/src/AspNetCore/Subscriptions/KeepConnectionAliveJob.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Net.WebSockets;
 using System.Threading;
 using System.Threading.Tasks;
 using HotChocolate.AspNetCore.Subscriptions.Messages;
@@ -52,6 +53,10 @@ await _connection.SendAsync(
             {
                 // the message processing was canceled.
             }
+            catch (WebSocketException)
+            {
+                // we will just stop receiving
+            }
         }
     }
 }

src/HotChocolate/AspNetCore/src/AspNetCore/Subscriptions/MessageProcessor.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Buffers;
 using System.IO.Pipelines;
+using System.Net.WebSockets;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -67,6 +68,10 @@ await _pipeline.ProcessAsync(
                 }
             }
             catch(OperationCanceledException) when (cancellationToken.IsCancellationRequested) { }
+            catch (WebSocketException)
+            {
+                // we will just stop receiving
+            }
             finally
             {
                 // reader should be completed always, so that related pipe writer can

src/HotChocolate/AspNetCore/src/AspNetCore/Subscriptions/WebSocketConnection.cs

@@ -63,7 +63,7 @@ public Task SendAsync(
         {
             WebSocket? webSocket = _webSocket;
 
-            if (_disposed || webSocket == null)
+            if (_disposed || webSocket == null || webSocket.State != WebSocketState.Open)
             {
                 return Task.CompletedTask;
             }
@@ -95,6 +95,11 @@ public async Task ReceiveAsync(
 
                     if (success)
                     {
+                        if (webSocket.State != WebSocketState.Open)
+                        {
+                            break;
+                        }
+
                         try
                         {
                             socketResult = await webSocket.ReceiveAsync(buffer, cancellationToken);
@@ -122,6 +127,10 @@ public async Task ReceiveAsync(
             {
                 // we will just stop receiving
             }
+            catch (WebSocketException)
+            {
+	            // we will just stop receiving
+            }
         }
 
         public async Task CloseAsync(
@@ -133,7 +142,7 @@ public async Task CloseAsync(
             {
                 WebSocket? webSocket = _webSocket;
 
-                if (_disposed || Closed || webSocket is null)
+                if (_disposed || Closed || webSocket is null || webSocket.State != WebSocketState.Open)
                 {
                     return;
                 }

src/HotChocolate/Core/src/Execution/Processing/ResolverTask.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
+using System.Threading.Channels;
 using System.Threading.Tasks;
 using HotChocolate.Types;
 
@@ -34,6 +35,10 @@ private async ValueTask TryExecuteAndCompleteAsync(CancellationToken cancellatio
                     CompleteValue(success, cancellationToken);
                 }
             }
+            catch (ObjectDisposedException)
+            {
+                IsCanceled = true;
+            }
             catch
             {
                 IsCanceled = true;
@@ -52,10 +57,28 @@ private async ValueTask TryExecuteAndCompleteAsync(CancellationToken cancellatio
                 }
                 else
                 {
-                    _operationContext.Execution.TaskStats.TaskCompleted();
+                    try
+                    {
+                        _operationContext.Execution.TaskStats.TaskCompleted();
+                    }
+                    catch (ChannelClosedException)
+                    {
+                    }
+                    catch (ObjectDisposedException)
+                    {
+                    }
                 }
 
-                _operationContext.Execution.TaskPool.Return(this);
+                try
+                {
+                    _operationContext.Execution.TaskPool.Return(this);
+                }
+                catch (ChannelClosedException)
+                {
+                }
+                catch (ObjectDisposedException)
+                {
+                }
             }
         }
 

src/HotChocolate/Core/src/Fetching/BatchScheduler.cs

@@ -110,7 +110,13 @@ private async ValueTask ExecuteAsync(CancellationToken cancellationToken)
                 finally
                 {
                     IsCanceled = cancellationToken.IsCancellationRequested;
-                    _context.Completed();
+                    try
+                    {
+                        _context.Completed();
+                    }
+                    catch (ObjectDisposedException)
+                    {
+                    }
                 }
             }
         }