ActiveSupport::Deprecator stop using Singleton

Followup: #47354 It does a bit more than just giving you a `.instance` method it also change the behavior of dup and clone, we don't need any of that, and `.instance` is deprecated anyway.
rails · Jun 5, 2023 · 9812641 · 9812641
1 parent 628cdf9
commit 9812641
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/activesupport/lib/active_support/deprecation.rb b/activesupport/lib/active_support/deprecation.rb
@@ -52,7 +52,6 @@ class Deprecation
     require "active_support/core_ext/module/deprecation"
     require "concurrent/atomic/thread_local_var"
 
-    include Singleton # :nodoc:
     include InstanceDelegator
     include Behavior
     include Reporting

diff --git a/activesupport/lib/active_support/deprecation/instance_delegator.rb b/activesupport/lib/active_support/deprecation/instance_delegator.rb
@@ -4,13 +4,14 @@ module ActiveSupport
   class Deprecation
     module InstanceDelegator # :nodoc:
       def self.included(base)
-        base.singleton_class.alias_method(:_instance, :instance)
         base.extend(ClassMethods)
         base.singleton_class.prepend(OverrideDelegators)
-        base.public_class_method :new
       end
 
       module ClassMethods # :nodoc:
+        MUTEX = Mutex.new
+        private_constant :MUTEX
+
         def include(included_module)
           included_module.instance_methods.each { |m| method_added(m) }
           super
@@ -40,7 +41,11 @@ def #{method_name}(#{args})
 
         def instance
           ActiveSupport.deprecator.warn("ActiveSupport::Deprecation.instance is deprecated (use your own Deprecation object)")
-          super
+          _instance
+        end
+
+        def _instance
+          @_instance ||= MUTEX.synchronize { @_instance ||= new }
         end
       end