Merge pull request #29788 from kamipo/remove_unused_mutex_m

Remove unused `Mutex_m` in Active Model

1 files changed, 4 insertions, 7 deletions

diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 7088435090..888a431e5f 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require "concurrent/map"
-require "mutex_m"
 
 module ActiveModel
   # Raised when an attribute is not defined.
@@ -329,13 +328,11 @@ module ActiveModel
         attribute_method_matchers_cache.clear
       end
 
-      def generated_attribute_methods #:nodoc:
-        @generated_attribute_methods ||= Module.new {
-          extend Mutex_m
-        }.tap { |mod| include mod }
-      end
-
       private
+        def generated_attribute_methods
+          @generated_attribute_methods ||= Module.new.tap { |mod| include mod }
+        end
+
         def instance_method_already_implemented?(method_name)
           generated_attribute_methods.method_defined?(method_name)
         end