doc

Author: stephen-derosa

include/livekit/subscription_thread_dispatcher.h

@@ -329,7 +329,10 @@ class LIVEKIT_API SubscriptionThreadDispatcher {
   /// must be joined after releasing the lock.
   std::thread extractReaderThreadLocked(const CallbackKey& key);
 
-  /// Select the appropriate reader startup path for @p track.
+  /// Select the appropriate reader startup path for @p media track.
+  ///
+  /// This is called by @ref Room when a remote track is subscribed. If a reader is already active for the given key,
+  /// std::thread default constructed is returned.
   ///
   /// Must be called with @ref lock_ held.
   std::thread startReaderLocked(const CallbackKey& key, const std::shared_ptr<Track>& track);