potential resolve disposal crashes and race conditions

LightlessSync/Services/LightFinder/LightFinderScannerService.cs

@@ -1,4 +1,4 @@
-using Dalamud.Plugin.Services;
+using Dalamud.Plugin.Services;
 using LightlessSync.API.Dto.User;
 using LightlessSync.Services.ActorTracking;
 using LightlessSync.Services.Mediator;
@@ -33,6 +33,7 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
     private const int _maxQueueSize = 100;
 
     private volatile bool _batchRunning = false;
+    private volatile bool _disposed = false;
 
     public IReadOnlyDictionary<string, BroadcastEntry> BroadcastCache => _broadcastCache;
     public readonly record struct BroadcastEntry(bool IsBroadcasting, DateTime ExpiryTime, string? GID);
@@ -63,6 +64,9 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
 
     public void Update()
     {
+        if (_disposed)
+            return;
+
         _frameCounter++;
         var lookupsThisFrame = 0;
 
@@ -104,7 +108,14 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
 
     private async Task BatchUpdateBroadcastCacheAsync(List<string> cids)
     {
+        if (_disposed)
+            return;
+
         var results = await _broadcastService.AreUsersBroadcastingAsync(cids).ConfigureAwait(false);
+        
+        if (_disposed)
+            return;
+
         var now = DateTime.UtcNow;
 
         foreach (var (cid, info) in results)
@@ -123,6 +134,9 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
                 (_, old) => new BroadcastEntry(info.IsBroadcasting, expiry, info.GID));
         }
 
+        if (_disposed)
+            return;
+
         var activeCids = _broadcastCache
             .Where(e => e.Value.IsBroadcasting && e.Value.ExpiryTime > now)
             .Select(e => e.Key)
@@ -134,6 +148,9 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
 
     private void OnBroadcastStatusChanged(BroadcastStatusChangedMessage msg)
     {
+        if (_disposed)
+            return;
+
         if (!msg.Enabled)
         {
             _broadcastCache.Clear();
@@ -147,6 +164,9 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
 
     private void UpdateSyncshellBroadcasts()
     {
+        if (_disposed)
+            return;
+
         var now = DateTime.UtcNow;
         var newSet = _broadcastCache
             .Where(e => e.Value.IsBroadcasting && e.Value.ExpiryTime > now && !string.IsNullOrEmpty(e.Value.GID))
@@ -230,17 +250,35 @@ public class LightFinderScannerService : DisposableMediatorSubscriberBase
 
     protected override void Dispose(bool disposing)
     {
+        _disposed = true;
         base.Dispose(disposing);
         _framework.Update -= OnFrameworkUpdate;
-        if (_cleanupTask != null)
+        
+        try
         {
-            _cleanupTask?.Wait(100, _cleanupCts.Token);
+            _cleanupCts.Cancel();
+        }
+        catch (ObjectDisposedException)
+        {
+            // Already disposed, can be ignored :)
         }
 
-        _cleanupCts.Cancel();
-        _cleanupCts.Dispose();
+        try
+        {
+            _cleanupTask?.Wait(100);
+        }
+        catch (Exception)
+        {
+            // Task may have already completed or been cancelled?
+        }
 
-        _cleanupTask?.Wait(100);
-        _cleanupCts.Dispose();
+        try
+        {
+            _cleanupCts.Dispose();
+        }
+        catch (ObjectDisposedException)
+        {
+            // Already disposed, ignore
+        }
     }
 }