5 files changed, 12 insertions, 31 deletions
diff --git a/activerecord/lib/active_record/connection_handling.rb b/activerecord/lib/active_record/connection_handling.rb
index 3f175988db..a1943dfcb0 100644
--- a/activerecord/lib/active_record/connection_handling.rb
+++ b/activerecord/lib/active_record/connection_handling.rb
@@ -54,11 +54,11 @@ module ActiveRecord
     end
 
     def connection_id
-      ActiveRecord::RuntimeRegistry.instance.connection_id
+      ActiveRecord::RuntimeRegistry.connection_id
     end
 
     def connection_id=(connection_id)
-      ActiveRecord::RuntimeRegistry.instance.connection_id = connection_id
+      ActiveRecord::RuntimeRegistry.connection_id = connection_id
     end
 
     # Returns the configuration of the associated connection as a hash:
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 7a8408155a..733d4e1c67 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -80,11 +80,11 @@ module ActiveRecord
       class_attribute :default_connection_handler, instance_writer: false
 
       def self.connection_handler
-        ActiveRecord::RuntimeRegistry.instance.connection_handler || self.default_connection_handler
+        ActiveRecord::RuntimeRegistry.connection_handler || default_connection_handler
       end
 
       def self.connection_handler=(handler)
-        ActiveRecord::RuntimeRegistry.instance.connection_handler = handler
+        ActiveRecord::RuntimeRegistry.connection_handler = handler
       end
 
       self.default_connection_handler = ConnectionAdapters::ConnectionHandler.new
diff --git a/activerecord/lib/active_record/log_subscriber.rb b/activerecord/lib/active_record/log_subscriber.rb
index 69371a1dab..61e5c120df 100644
--- a/activerecord/lib/active_record/log_subscriber.rb
+++ b/activerecord/lib/active_record/log_subscriber.rb
@@ -3,11 +3,11 @@ module ActiveRecord
     IGNORE_PAYLOAD_NAMES = ["SCHEMA", "EXPLAIN"]
 
     def self.runtime=(value)
-      ActiveRecord::RuntimeRegistry.instance.sql_runtime = value
+      ActiveRecord::RuntimeRegistry.sql_runtime = value
     end
 
     def self.runtime
-      ActiveRecord::RuntimeRegistry.instance.sql_runtime ||= 0
+      ActiveRecord::RuntimeRegistry.sql_runtime ||= 0
     end
 
     def self.reset_runtime
diff --git a/activerecord/lib/active_record/runtime_registry.rb b/activerecord/lib/active_record/runtime_registry.rb
index 3f0ac68143..17890dd29f 100644
--- a/activerecord/lib/active_record/runtime_registry.rb
+++ b/activerecord/lib/active_record/runtime_registry.rb
@@ -1,29 +1,14 @@
 require 'active_support/per_thread_registry'
 
 module ActiveRecord
-  # This is a registry class for storing local variables in active record. The
-  # class allows you to access variables that are local to the current thread.
-  # These thread local variables are stored as attributes in the
-  # +RuntimeRegistry+ class.
-  #
-  # You can access the thread local variables by calling a variable's name on
-  # the +RuntimeRegistry+ class. For example, if you wanted to obtain the
-  # connection handler for the current thread, you would invoke:
-  #
-  #   ActiveRecord::RuntimeRegistry.instance.connection_handler
-  #
-  # The +PerThreadRegistry+ module will make a new +RuntimeRegistry+ instance
-  # and store it in +Thread.current+. Whenever you make a call for an attribute
-  # on the +RuntimeRegistry+ class, the call will be sent to the instance that
-  # is stored in +Thread.current+.
-  #
-  # Note that you can also make the following call which would provide an
-  # equivalent result as the previous code:
+  # This is a thread locals registry for Active Record. For example
   #
   #   ActiveRecord::RuntimeRegistry.connection_handler
   #
-  # However, this is less performant because it makes a call to +method_missing+
-  # before it sends the method call to the +instance+.
+  # returns the connection handler local to the current thread.
+  #
+  # See the documentation of <tt>ActiveSupport::PerThreadRegistry</tt>
+  # for further details.
   class RuntimeRegistry
     extend ActiveSupport::PerThreadRegistry
 
diff --git a/activerecord/lib/active_record/scoping.rb b/activerecord/lib/active_record/scoping.rb
index 6ab36a23a7..0cf3d59985 100644
--- a/activerecord/lib/active_record/scoping.rb
+++ b/activerecord/lib/active_record/scoping.rb
@@ -36,7 +36,7 @@ module ActiveRecord
     # to get the current_scope for the +Board+ model, then you would use the
     # following code:
     #
-    #   registry = ActiveRecord::Scoping::ScopeRegistry.instance
+    #   registry = ActiveRecord::Scoping::ScopeRegistry
     #   registry.set_value_for(:current_scope, "Board", some_new_scope)
     #
     # Now when you run:
@@ -52,10 +52,6 @@ module ActiveRecord
     class ScopeRegistry # :nodoc:
       extend ActiveSupport::PerThreadRegistry
 
-      class << self
-        delegate :value_for, :set_value_for, to: :instance
-      end
-
       VALID_SCOPE_TYPES = [:current_scope, :ignore_default_scope]
 
       def initialize