Add lock to FSWatcher change queue

Author: mizantrop777

src/Plugins/Watchers/FSWatcher.cs

@@ -34,6 +34,7 @@ private class QueuedChange
 
         // Changes are buffered briefly to avoid duplicate events
         private Dictionary<string, QueuedChange> changeQueue;
+        private readonly object changeQueueLock = new object();
 
         private Timer timers;
 
@@ -172,43 +173,47 @@ private void watcher_Changed(object sender, FileSystemEventArgs e)
             int length = e.FullPath.Length - watcher.Path.Length - Path.GetExtension(e.Name).Length - 1;
             string subPath = e.FullPath.Substring(watcher.Path.Length + 1, length);
 
-            if (!changeQueue.TryGetValue(subPath, out QueuedChange change))
+            QueuedChange change;
+            lock (changeQueueLock)
             {
-                change = new QueuedChange();
-                changeQueue[subPath] = change;
-            }
-            change.timer?.Destroy();
-            change.timer = null;
+                if (!changeQueue.TryGetValue(subPath, out change))
+                {
+                    change = new QueuedChange();
+                    changeQueue[subPath] = change;
+                }
+                change.timer?.Destroy();
+                change.timer = null;
 
-            switch (e.ChangeType)
-            {
-                case WatcherChangeTypes.Changed:
-                    if (change.type != WatcherChangeTypes.Created)
-                    {
-                        change.type = WatcherChangeTypes.Changed;
-                    }
-                    break;
+                switch (e.ChangeType)
+                {
+                    case WatcherChangeTypes.Changed:
+                        if (change.type != WatcherChangeTypes.Created)
+                        {
+                            change.type = WatcherChangeTypes.Changed;
+                        }
+                        break;
 
-                case WatcherChangeTypes.Created:
-                    if (change.type == WatcherChangeTypes.Deleted)
-                    {
-                        change.type = WatcherChangeTypes.Changed;
-                    }
-                    else
-                    {
-                        change.type = WatcherChangeTypes.Created;
-                    }
-                    break;
+                    case WatcherChangeTypes.Created:
+                        if (change.type == WatcherChangeTypes.Deleted)
+                        {
+                            change.type = WatcherChangeTypes.Changed;
+                        }
+                        else
+                        {
+                            change.type = WatcherChangeTypes.Created;
+                        }
+                        break;
 
-                case WatcherChangeTypes.Deleted:
-                    if (change.type == WatcherChangeTypes.Created)
-                    {
-                        changeQueue.Remove(subPath);
-                        return;
-                    }
+                    case WatcherChangeTypes.Deleted:
+                        if (change.type == WatcherChangeTypes.Created)
+                        {
+                            changeQueue.Remove(subPath);
+                            return;
+                        }
 
-                    change.type = WatcherChangeTypes.Deleted;
-                    break;
+                        change.type = WatcherChangeTypes.Deleted;
+                        break;
+                }
             }
 
             Interface.Oxide.NextTick(() =>
@@ -238,8 +243,11 @@ private void watcher_Changed(object sender, FileSystemEventArgs e)
                 change.timer?.Destroy();
                 change.timer = timers.Once(.2f, () =>
                 {
-                    change.timer = null;
-                    changeQueue.Remove(subPath);
+                    lock (changeQueueLock)
+                    {
+                        change.timer = null;
+                        changeQueue.Remove(subPath);
+                    }
 
                     if (Regex.Match(subPath, @"include\\", RegexOptions.IgnoreCase).Success)
                     {