#428

backend/app/models/locale.rb

@@ -1,4 +1,5 @@
 class Locale < ApplicationRecord
+  before_save :lock_tag_creation!, if: :will_generate_tag_names?
   after_save :generate_tag_names!, if: :needs_tag_names?
 
   belongs_to :language, foreign_key: :language_code, primary_key: :code
@@ -10,6 +11,14 @@ class Locale < ApplicationRecord
 
   private
 
+  def will_generate_tag_names?
+    deprecated_at.nil? && (will_save_change_to_code? || will_save_change_to_deprecated_at?)
+  end
+
+  def lock_tag_creation!
+    SharedResourceIdAllocator.lock_space!(Tag, 'tags')
+  end
+
   def needs_tag_names?
     deprecated_at.nil? && (saved_change_to_code? || saved_change_to_deprecated_at?)
   end

backend/app/models/tag.rb

@@ -259,7 +259,8 @@ class Tag < ApplicationRecord
       name = name.to_s.strip
 
       ApplicationRecord.transaction do
-        tn = TagName.find_by(language_code:, name:)
+        SharedResourceIdAllocator.lock_space!(Tag, 'tags')
+        tn = TagName.lock.find_by(language_code:, name:)
         next tn.tag if tn
 
         tag = Tag.create!(category:)