fix: Pin CallbackDelegate with GCHandle to prevent GC collection on .…

managed/CounterStrikeSharp.API/Core/BasePlugin.cs

@@ -665,32 +665,32 @@ protected virtual void Dispose(bool disposing)
             if (_disposed) return;
             if (!disposing) return;
 
-            foreach (var subscriber in Handlers.Values)
+            foreach (var subscriber in Handlers.Values.ToList())
             {
                 subscriber.Dispose();
             }
 
-            foreach (var subscriber in CommandListeners.Values)
+            foreach (var subscriber in CommandListeners.Values.ToList())
             {
                 subscriber.Dispose();
             }
 
-            foreach (var subscriber in Listeners.Values)
+            foreach (var subscriber in Listeners.Values.ToList())
             {
                 subscriber.Dispose();
             }
 
-            foreach (var subscriber in EntityOutputHooks.Values)
+            foreach (var subscriber in EntityOutputHooks.Values.ToList())
             {
                 subscriber.Dispose();
             }
 
-            foreach (var definition in CommandDefinitions)
+            foreach (var definition in CommandDefinitions.ToList())
             {
                 CommandManager.RemoveCommand(definition);
             }
 
-            foreach (var timer in Timers)
+            foreach (var timer in Timers.ToList())
             {
                 timer.Kill();
             }

managed/CounterStrikeSharp.API/Core/FunctionReference.cs

@@ -49,6 +49,7 @@ public class FunctionReference
 
         private readonly Delegate _targetMethod;
         private readonly CallbackDelegate _nativeCallback;
+        private readonly GCHandle _nativeCallbackHandle;
 
         private readonly TaskCompletionSource _taskCompletionSource = new();
 
@@ -57,6 +58,7 @@ private FunctionReference(Delegate method, FunctionLifetime lifetime)
             Lifetime = lifetime;
             _targetMethod = method;
             _nativeCallback = CreateWrappedCallback();
+            _nativeCallbackHandle = GCHandle.Alloc(_nativeCallback);
         }
 
         /// <summary>
@@ -178,6 +180,11 @@ public static void Remove(int reference)
 
                 IdToFunctionReferencesMap.Remove(reference, out _);
 
+                if (functionReference._nativeCallbackHandle.IsAllocated)
+                {
+                    functionReference._nativeCallbackHandle.Free();
+                }
+
                 Application.Instance.Logger.LogDebug("Removing function/callback reference: {Reference}", reference);
             }
         }