enable cancelling pending thread queue actions on dispose

Author: pandinocoder

Framework/Intersect.Framework/Threading/ActionQueue.cs

@@ -23,6 +23,8 @@ protected ActionQueue(Action<TActionQueue>? beginInvokePending, Action<TActionQu
 
     protected abstract Action<TEnqueueState> PostInvocationAction { get; }
 
+    public virtual void ClearPending() { }
+
     /// <summary>
     ///
     /// </summary>

Framework/Intersect.Framework/Threading/ThreadQueue.cs

@@ -8,6 +8,7 @@ public sealed partial class ThreadQueue : ActionQueue<ThreadQueue, ManualResetEv
 
     private readonly object _lock = new();
     private readonly Stack<ManualResetEventSlim> _resetEventPool = [];
+    private readonly HashSet<CancellationTokenSource> _pendingCancellationTokenSources = [];
     private readonly int? _spinCount;
 
     private int _mainThreadId;
@@ -34,12 +35,55 @@ public bool IsOnMainThread
         get => _mainThreadId == Environment.CurrentManagedThreadId;
     }
 
+    public override void ClearPending()
+    {
+        base.ClearPending();
+
+        CancellationTokenSource[] pendingCancellationTokenSources;
+        lock (_pendingCancellationTokenSources)
+        {
+            pendingCancellationTokenSources = _pendingCancellationTokenSources.ToArray();
+            _pendingCancellationTokenSources.Clear();
+        }
+
+        foreach (var cancellationTokenSource in pendingCancellationTokenSources)
+        {
+            cancellationTokenSource.Cancel();
+        }
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static void BeginInvokePending(ThreadQueue @this) => @this.ThrowIfNotOnMainThread();
 
     protected override ManualResetEventSlim EnqueueCreateState() => ResetEventPoolPop();
 
-    protected override void EnqueueSuccessful(ManualResetEventSlim resetEvent) => resetEvent.Wait();
+    protected override void EnqueueSuccessful(ManualResetEventSlim resetEvent)
+    {
+        CancellationTokenSource cancellationTokenSource = new();
+
+        lock (_pendingCancellationTokenSources)
+        {
+            _pendingCancellationTokenSources.Add(cancellationTokenSource);
+        }
+
+        try
+        {
+            resetEvent.Wait(cancellationTokenSource.Token);
+        }
+        catch (OperationCanceledException operationCanceledException)
+        {
+            if (!cancellationTokenSource.IsCancellationRequested ||
+                !operationCanceledException.CancellationToken.Equals(cancellationTokenSource.Token))
+            {
+                throw;
+            }
+        }
+
+        lock (_pendingCancellationTokenSources)
+        {
+            _pendingCancellationTokenSources.Remove(cancellationTokenSource);
+        }
+    }
 
     protected override void EnqueueFinally(ManualResetEventSlim resetEvent) => ResetEventPoolPush(resetEvent);
 

Intersect.Client.Framework/Gwen/Control/Base.Threading.cs

@@ -1,4 +1,6 @@
+using Intersect.Core;
 using Intersect.Framework.Threading;
+using Microsoft.Extensions.Logging;
 
 namespace Intersect.Client.Framework.Gwen.Control;
 
@@ -60,6 +62,21 @@ public TReturn RunOnMainThread<TState, TReturn>(
 
     public void RunOnMainThread<TState0, TState1>(Action<TState0, TState1> action, TState0 state0, TState1 state1)
     {
+        if (_disposed)
+        {
+            if (_disposeCompleted)
+            {
+                // TODO: Turn this into a LogError() after we see some reports
+                ObjectDisposedException.ThrowIf(true, this);
+            }
+
+            ApplicationContext.CurrentContext.Logger.LogTrace(
+                "RunOnMainThread() called after {NodeName} was disposed",
+                CanonicalName
+            );
+            return;
+        }
+
         Invalidate();
         _threadQueue.RunOnMainThread(action, state0, state1);
     }

Intersect.Client.Framework/Gwen/Control/Base.cs

@@ -1287,6 +1287,8 @@ public void Dispose()
 
         _disposed = true;
 
+        _threadQueue.ClearPending();
+
         Dispose(disposing: true);
 
         ICacheToTexture? cache = default;