wait until after transaction for track changes

ruby/lib/jam_ruby/connection_manager.rb

@@ -353,19 +353,22 @@ SQL
     end
 
     def update_session_controller(music_session_id)
+      tracks_changed = false
       active_music_session = ActiveMusicSession.find(music_session_id)
 
       if active_music_session
         music_session = active_music_session.music_session
         if music_session.session_controller_id && !active_music_session.users.exists?(music_session.session_controller.id)
           # find next in line, because the current 'session controller' is not part of the session
-          next_in_line(music_session, active_music_session)
+          tracks_changed = next_in_line(music_session, active_music_session)
         end
       end
+      tracks_changed
     end
 
     # determine who should be session controller after someone leaves
     def next_in_line(music_session, active_music_session)
+      tracks_changed = false
       session_users = active_music_session.users
 
       # check friends 1st
@@ -374,7 +377,7 @@ SQL
         music_session.session_controller = session_friends[0]
         if music_session.save
           active_music_session.tick_track_changes
-          Notification.send_tracks_changed(active_music_session)
+          tracks_changed = true
           return
         end
       end
@@ -385,7 +388,7 @@ SQL
         music_session.session_controller = invited[0]
         if music_session.save
           active_music_session.tick_track_changes
-          Notification.send_tracks_changed(active_music_session)
+          tracks_changed = true
           return
         end
       end
@@ -397,16 +400,17 @@ SQL
         music_session.session_controller = earliest
         if music_session.save
           active_music_session.tick_track_changes
-          Notification.send_tracks_changed(active_music_session)
+          tracks_changed = true
           return
         end
       end
-      music_session.creator
+      tracks_changed
     end
 
     def join_music_session(user, client_id, music_session, as_musician, tracks, audio_latency, client_role = nil, parent_client_id = nil, video_sources=nil)
       connection = nil
 
+      tracks_changed = false
       ConnectionManager.active_record_transaction do |connection_manager|
         db_conn = connection_manager.pg_conn
 
@@ -432,11 +436,15 @@ SQL
         if connection.errors.any?
           raise ActiveRecord::Rollback
         else
-          update_session_controller(music_session.id)
+          tracks_changed = update_session_controller(music_session.id)
         end
 
       end
 
+      if tracks_changed
+        Notification.send_tracks_changed(music_session.active_music_session)
+      end
+
       connection
     end
 
@@ -444,6 +452,7 @@ SQL
     # if a blk is passed in, upon success, it will be called and you can issue notifications
     # within the connection table lock
     def leave_music_session(user, connection, music_session, &blk)
+      send_tracks_changed = false
       ConnectionManager.active_record_transaction do |connection_manager|
 
         conn = connection_manager.pg_conn
@@ -469,7 +478,7 @@ SQL
           if result.cmd_tuples == 1
             @log.debug("disassociated music_session with connection for client_id=#{client_id}, user_id=#{user_id}")
 
-            update_session_controller(music_session.id)
+            send_tracks_changed = update_session_controller(music_session.id)
 
             JamRuby::MusicSessionUserHistory.removed_music_session(user_id, music_session_id)
             session_checks(conn, previous_music_session_id, user_id)
@@ -484,6 +493,10 @@ SQL
           end
         end
       end
+
+      if send_tracks_changed
+        Notification.send_tracks_changed(music_session.active_music_session)
+      end
     end
 
     def lock_connections(conn)

web/lib/music_session_manager.rb

@@ -98,13 +98,15 @@ class MusicSessionManager < BaseManager
   def participant_create(user, music_session_id, client_id, as_musician, tracks, audio_latency)
     connection = nil
     music_session = nil
+    active_music_session = nil
+    send_track_changed = false
     ActiveRecord::Base.transaction do
 
       active_music_session = ActiveMusicSession.find(music_session_id)
 
       active_music_session.with_lock do # VRFS-1297
         active_music_session.tick_track_changes
-        Notification.send_tracks_changed(active_music_session)
+        send_track_changed = true
         connection = ConnectionManager.new.join_music_session(user, client_id, active_music_session, as_musician, tracks, audio_latency)
 
         if connection.errors.any?
@@ -114,6 +116,9 @@ class MusicSessionManager < BaseManager
       end
 
     end
+    if send_track_changed
+      Notification.send_tracks_changed(active_music_session)
+    end
 
     unless connection.errors.any?
       user.update_progression_field(:first_music_session_at)
@@ -144,15 +149,20 @@ class MusicSessionManager < BaseManager
 
     recordingId = nil
 
+    tracks_changed = false
     active_music_session.with_lock do # VRFS-1297
       ConnectionManager.new.leave_music_session(user, connection, active_music_session) do
         active_music_session.tick_track_changes
-        Notification.send_tracks_changed(active_music_session)
+        tracks_changed = true
         recording =  active_music_session.stop_recording # stop any ongoing recording, if there is one
         recordingId = recording.id unless recording.nil?
       end
     end
 
+    if tracks_changed
+      Notification.send_tracks_changed(active_music_session)
+    end
+
     Notification.send_session_depart(active_music_session, connection.client_id, user, recordingId)
   end