Eliminate internal uses of `PerThreadRegistry` and deprecate it

This module has been soft deprecated for a long time, but since
it was used internally it wasn't throwing deprecation warnings.

Now we can throw a deprecation warning.

actionview/lib/action_view/helpers/cache_helper.rb

@@ -292,19 +292,20 @@ module ActionView
         controller.write_fragment(name, fragment, options)
       end
 
-      class CachingRegistry
+      module CachingRegistry # :nodoc:
-        extend ActiveSupport::PerThreadRegistry
+        extend self
 
-        attr_accessor :caching
+        def caching?
-        alias caching? caching
+          ActiveSupport::IsolatedExecutionState[:action_view_caching] ||= false
+        end
 
-        def self.track_caching
+        def track_caching
-          caching_was = self.caching
+          caching_was = ActiveSupport::IsolatedExecutionState[:action_view_caching]
-          self.caching = true
+          ActiveSupport::IsolatedExecutionState[:action_view_caching] = true
 
           yield
         ensure
-          self.caching = caching_was
+          ActiveSupport::IsolatedExecutionState[:action_view_caching] = caching_was
         end
       end
     end

activerecord/lib/active_record/explain_registry.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "active_support/per_thread_registry"
+require "active_support/core_ext/module/delegation"
 
 module ActiveRecord
   # This is a thread locals registry for EXPLAIN. For example
@@ -8,13 +8,18 @@ module ActiveRecord
   #   ActiveRecord::ExplainRegistry.queries
   #
   # returns the collected queries local to the current thread.
-  #
-  # See the documentation of ActiveSupport::PerThreadRegistry
-  # for further details.
   class ExplainRegistry # :nodoc:
-    extend ActiveSupport::PerThreadRegistry
+    class << self
+      delegate :reset, :collect, :collect=, :collect?, :queries, to: :instance
 
-    attr_accessor :queries, :collect
+      private
+        def instance
+          ActiveSupport::IsolatedExecutionState[:active_record_explain_registry] ||= new
+        end
+    end
+
+    attr_accessor :collect
+    attr_reader :queries
 
     def initialize
       reset

activerecord/lib/active_record/relation/record_fetch_warning.rb

@@ -31,17 +31,15 @@ module ActiveRecord
       end
       # :startdoc:
 
-      class QueryRegistry # :nodoc:
+      module QueryRegistry # :nodoc:
-        extend ActiveSupport::PerThreadRegistry
+        extend self
 
-        attr_reader :queries
+        def queries
-
+          ActiveSupport::IsolatedExecutionState[:active_record_query_registry] ||= []
-        def initialize
-          @queries = []
         end
 
         def reset
-          @queries.clear
+          queries.clear
         end
       end
     end

activerecord/lib/active_record/runtime_registry.rb

@@ -1,22 +1,20 @@
 # frozen_string_literal: true
 
-require "active_support/per_thread_registry"
-
 module ActiveRecord
   # This is a thread locals registry for Active Record. For example:
   #
-  #   ActiveRecord::RuntimeRegistry.connection_handler
+  #   ActiveRecord::RuntimeRegistry.sql_runtime
   #
-  # returns the connection handler local to the current thread.
+  # returns the connection handler local to the current unit of execution (either thread of fiber).
-  #
+  module RuntimeRegistry # :nodoc:
-  # See the documentation of ActiveSupport::PerThreadRegistry
+    extend self
-  # for further details.
-  class RuntimeRegistry # :nodoc:
-    extend ActiveSupport::PerThreadRegistry
 
-    attr_accessor :sql_runtime
+    def sql_runtime
+      ActiveSupport::IsolatedExecutionState[:active_record_sql_runtime]
+    end
 
-    def self.sql_runtime; instance.sql_runtime; end
+    def sql_runtime=(runtime)
-    def self.sql_runtime=(x); instance.sql_runtime = x; end
+      ActiveSupport::IsolatedExecutionState[:active_record_sql_runtime] = runtime
+    end
   end
 end

activerecord/lib/active_record/scoping.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "active_support/per_thread_registry"
+require "active_support/core_ext/module/delegation"
 
 module ActiveRecord
   module Scoping
@@ -57,8 +57,8 @@ module ActiveRecord
     end
 
     # This class stores the +:current_scope+ and +:ignore_default_scope+ values
-    # for different classes. The registry is stored as a thread local, which is
+    # for different classes. The registry is stored as either a thread or fiber
-    # accessed through +ScopeRegistry.current+.
+    # local depending on the application configuration.
     #
     # This class allows you to store and get the scope values on different
     # classes and different types of scopes. For example, if you are attempting
@@ -66,22 +66,22 @@ module ActiveRecord
     # following code:
     #
     #   registry = ActiveRecord::Scoping::ScopeRegistry
-    #   registry.set_value_for(:current_scope, Board, some_new_scope)
+    #   registry.set_current_scope(Board, some_new_scope)
     #
     # Now when you run:
     #
-    #   registry.value_for(:current_scope, Board)
+    #   registry.current_scope(Board)
     #
-    # You will obtain whatever was defined in +some_new_scope+. The #value_for
+    # You will obtain whatever was defined in +some_new_scope+.
-    # and #set_value_for methods are delegated to the current ScopeRegistry
-    # object, so the above example code can also be called as:
-    #
-    #   ActiveRecord::Scoping::ScopeRegistry.set_value_for(:current_scope,
-    #       Board, some_new_scope)
     class ScopeRegistry # :nodoc:
-      extend ActiveSupport::PerThreadRegistry
+      class << self
+        delegate :current_scope, :set_current_scope, :ignore_default_scope, :set_ignore_default_scope,
+          :global_current_scope, :set_global_current_scope, to: :instance
 
-      VALID_SCOPE_TYPES = [:current_scope, :ignore_default_scope, :global_current_scope]
+        def instance
+          ActiveSupport::IsolatedExecutionState[:active_record_scope_registry] ||= new
+        end
+      end
 
       def initialize
         @current_scope        = {}
@@ -89,16 +89,28 @@ module ActiveRecord
         @global_current_scope = {}
       end
 
-      VALID_SCOPE_TYPES.each do |type|
+      def current_scope(model, skip_inherited_scope = false)
-        class_eval <<-eorb, __FILE__, __LINE__
+        value_for(@current_scope, model, skip_inherited_scope)
-        def #{type}(model, skip_inherited_scope = false)
+      end
-          value_for(@#{type}, model, skip_inherited_scope)
-        end
 
-        def set_#{type}(model, value)
+      def set_current_scope(model, value)
-          set_value_for(@#{type}, model, value)
+        set_value_for(@current_scope, model, value)
-        end
+      end
-        eorb
+
+      def ignore_default_scope(model, skip_inherited_scope = false)
+        value_for(@ignore_default_scope, model, skip_inherited_scope)
+      end
+
+      def set_ignore_default_scope(model, value)
+        set_value_for(@ignore_default_scope, model, value)
+      end
+
+      def global_current_scope(model, skip_inherited_scope = false)
+        value_for(@global_current_scope, model, skip_inherited_scope)
+      end
+
+      def set_global_current_scope(model, value)
+        set_value_for(@global_current_scope, model, value)
       end
 
       private

activerecord/lib/active_record/suppressor.rb

@@ -30,32 +30,28 @@ module ActiveRecord
   module Suppressor
     extend ActiveSupport::Concern
 
+    class << self
+      def registry # :nodoc:
+        ActiveSupport::IsolatedExecutionState[:active_record_suppresor_registry] ||= {}
+      end
+    end
+
     module ClassMethods
       def suppress(&block)
-        previous_state = SuppressorRegistry.suppressed[name]
+        previous_state = Suppressor.registry[name]
-        SuppressorRegistry.suppressed[name] = true
+        Suppressor.registry[name] = true
         yield
       ensure
-        SuppressorRegistry.suppressed[name] = previous_state
+        Suppressor.registry[name] = previous_state
       end
     end
 
     def save(**) # :nodoc:
-      SuppressorRegistry.suppressed[self.class.name] ? true : super
+      Suppressor.registry[self.class.name] ? true : super
     end
 
     def save!(**) # :nodoc:
-      SuppressorRegistry.suppressed[self.class.name] ? true : super
+      Suppressor.registry[self.class.name] ? true : super
-    end
-  end
-
-  class SuppressorRegistry # :nodoc:
-    extend ActiveSupport::PerThreadRegistry
-
-    attr_reader :suppressed
-
-    def initialize
-      @suppressed = {}
     end
   end
 end

activesupport/lib/active_support.rb

@@ -51,6 +51,7 @@ module ActiveSupport
   autoload :IsolatedExecutionState
   autoload :Notifications
   autoload :Reloader
+  autoload :PerThreadRegistry
   autoload :SecureCompareRotator
 
   eager_autoload do

activesupport/lib/active_support/cache/strategy/local_cache.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require "active_support/core_ext/string/inflections"
-require "active_support/per_thread_registry"
 
 module ActiveSupport
   module Cache
@@ -13,23 +12,18 @@ module ActiveSupport
         autoload :Middleware, "active_support/cache/strategy/local_cache_middleware"
 
         # Class for storing and registering the local caches.
-        class LocalCacheRegistry # :nodoc:
+        module LocalCacheRegistry # :nodoc:
-          extend ActiveSupport::PerThreadRegistry
+          extend self
-
-          def initialize
-            @registry = {}
-          end
 
           def cache_for(local_cache_key)
-            @registry[local_cache_key]
+            registry = ActiveSupport::IsolatedExecutionState[:active_support_local_cache_registry] ||= {}
+            registry[local_cache_key]
           end
 
           def set_cache_for(local_cache_key, value)
-            @registry[local_cache_key] = value
+            registry = ActiveSupport::IsolatedExecutionState[:active_support_local_cache_registry] ||= {}
+            registry[local_cache_key] = value
           end
-
-          def self.set_cache_for(l, v); instance.set_cache_for l, v; end
-          def self.cache_for(l); instance.cache_for l; end
         end
 
         # Simple memory backed cache. This cache is not thread safe and is intended only

activesupport/lib/active_support/notifications.rb

@@ -2,7 +2,6 @@
 
 require "active_support/notifications/instrumenter"
 require "active_support/notifications/fanout"
-require "active_support/per_thread_registry"
 
 module ActiveSupport
   # = Notifications
@@ -261,28 +260,13 @@ module ActiveSupport
       end
 
       def instrumenter
-        InstrumentationRegistry.instance.instrumenter_for(notifier)
+        registry[notifier] ||= Instrumenter.new(notifier)
-      end
-    end
-
-    # This class is a registry which holds all of the +Instrumenter+ objects
-    # in a particular thread local. To access the +Instrumenter+ object for a
-    # particular +notifier+, you can call the following method:
-    #
-    #   InstrumentationRegistry.instrumenter_for(notifier)
-    #
-    # The instrumenters for multiple notifiers are held in a single instance of
-    # this class.
-    class InstrumentationRegistry # :nodoc:
-      extend ActiveSupport::PerThreadRegistry
-
-      def initialize
-        @registry = {}
       end
 
-      def instrumenter_for(notifier)
+      private
-        @registry[notifier] ||= Instrumenter.new(notifier)
+        def registry
-      end
+          ActiveSupport::IsolatedExecutionState[:active_support_notifications_registry] ||= {}
+        end
     end
 
     self.notifier = Fanout.new

activesupport/lib/active_support/per_thread_registry.rb

@@ -40,6 +40,10 @@ module ActiveSupport
   # If the class has an initializer, it must accept no arguments.
   module PerThreadRegistry
     def self.extended(object)
+      ActiveSupport::Deprecation.warn(<<~MSG)
+        ActiveSupport::PerThreadRegistry is deprecated and will be removed in Rails 7.1.
+        Use `Module#thread_mattr_accessor` instead.
+      MSG
       object.instance_variable_set :@per_thread_registry_key, object.name.freeze
     end
 

activesupport/lib/active_support/subscriber.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "active_support/per_thread_registry"
 require "active_support/notifications"
 
 module ActiveSupport
@@ -157,23 +156,8 @@ module ActiveSupport
 
     private
       def event_stack
-        SubscriberQueueRegistry.instance.get_queue(@queue_key)
+        registry = ActiveSupport::IsolatedExecutionState[:active_support_subscriber_queue_registry] ||= {}
+        registry[@queue_key] ||= []
       end
   end
-
-  # This is a registry for all the event stacks kept for subscribers.
-  #
-  # See the documentation of <tt>ActiveSupport::PerThreadRegistry</tt>
-  # for further details.
-  class SubscriberQueueRegistry # :nodoc:
-    extend PerThreadRegistry
-
-    def initialize
-      @registry = {}
-    end
-
-    def get_queue(queue_key)
-      @registry[queue_key] ||= []
-    end
-  end
 end

activesupport/test/per_thread_registry_test.rb

@@ -4,7 +4,9 @@ require_relative "abstract_unit"
 
 class PerThreadRegistryTest < ActiveSupport::TestCase
   class TestRegistry
-    extend ActiveSupport::PerThreadRegistry
+    ActiveSupport::Deprecation.silence do
+      extend ActiveSupport::PerThreadRegistry
+    end
 
     def foo(x:); x; end
   end