Merge pull request rails#49674 from Shopify/drop-mutex-m

Drop dependency on `mutex_m`

Author: byroot

Gemfile.lock

@@ -91,7 +91,6 @@ PATH
       drb
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
-      mutex_m
       tzinfo (~> 2.0)
     rails (7.2.0.alpha)
       actioncable (= 7.2.0.alpha)
@@ -342,7 +341,6 @@ GEM
     msgpack (1.7.0)
     multi_json (1.15.0)
     multipart-post (2.2.3)
-    mutex_m (0.1.2)
     mysql2 (0.5.5)
     net-http-persistent (4.0.1)
       connection_pool (~> 2.2)

actionpack/lib/action_controller/metal/params_wrapper.rb

@@ -84,11 +84,7 @@ module ParamsWrapper
 
     EXCLUDE_PARAMETERS = %w(authenticity_token _method utf8)
 
-    require "mutex_m"
-
     class Options < Struct.new(:name, :format, :include, :exclude, :klass, :model) # :nodoc:
-      include Mutex_m
-
       def self.from_hash(hash)
         name    = hash[:name]
         format  = Array(hash[:format])
@@ -99,6 +95,7 @@ def self.from_hash(hash)
 
       def initialize(name, format, include, exclude, klass, model) # :nodoc:
         super
+        @mutex = Mutex.new
         @include_set = include
         @name_set    = name
       end
@@ -111,7 +108,7 @@ def include
         return super if @include_set
 
         m = model
-        synchronize do
+        @mutex.synchronize do
           return super if @include_set
 
           @include_set = true
@@ -144,7 +141,7 @@ def name
         return super if @name_set
 
         m = model
-        synchronize do
+        @mutex.synchronize do
           return super if @name_set
 
           @name_set = true

activerecord/lib/active_record/attribute_methods.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "mutex_m"
 require "active_support/core_ext/enumerable"
 
 module ActiveRecord
@@ -24,7 +23,7 @@ module AttributeMethods
     RESTRICTED_CLASS_METHODS = %w(private public protected allocate new name parent superclass)
 
     class GeneratedAttributeMethods < Module # :nodoc:
-      include Mutex_m
+      LOCK = Monitor.new
     end
 
     class << self
@@ -68,7 +67,7 @@ def generate_alias_attributes # :nodoc:
         superclass.generate_alias_attributes unless superclass == Base
         return if @alias_attributes_mass_generated
 
-        generated_attribute_methods.synchronize do
+        GeneratedAttributeMethods::LOCK.synchronize do
           return if @alias_attributes_mass_generated
           ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |code_generator|
             aliases_by_attribute_name.each do |old_name, new_names|
@@ -127,7 +126,7 @@ def define_attribute_methods # :nodoc:
         return false if @attribute_methods_generated
         # Use a mutex; we don't want two threads simultaneously trying to define
         # attribute methods.
-        generated_attribute_methods.synchronize do
+        GeneratedAttributeMethods::LOCK.synchronize do
           return false if @attribute_methods_generated
           superclass.define_attribute_methods unless base_class?
           super(attribute_names)
@@ -136,7 +135,7 @@ def define_attribute_methods # :nodoc:
       end
 
       def undefine_attribute_methods # :nodoc:
-        generated_attribute_methods.synchronize do
+        GeneratedAttributeMethods::LOCK.synchronize do
           super if defined?(@attribute_methods_generated) && @attribute_methods_generated
           @attribute_methods_generated = false
           @alias_attributes_mass_generated = false

activerecord/lib/active_record/relation/delegation.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "mutex_m"
 require "active_support/core_ext/module/delegation"
 
 module ActiveRecord
@@ -67,10 +66,10 @@ def generated_relation_methods
     end
 
     class GeneratedRelationMethods < Module # :nodoc:
-      include Mutex_m
+      MUTEX = Mutex.new
 
       def generate_method(method)
-        synchronize do
+        MUTEX.synchronize do
           return if method_defined?(method)
 
           if /\A[a-zA-Z_]\w*[!?]?\z/.match?(method) && !DELEGATION_RESERVED_METHOD_NAMES.include?(method.to_s)

activesupport/activesupport.gemspec

@@ -41,6 +41,5 @@ Gem::Specification.new do |s|
   s.add_dependency "minitest",        ">= 5.1"
   s.add_dependency "base64"
   s.add_dependency "drb"
-  s.add_dependency "mutex_m"
   s.add_dependency "bigdecimal"
 end

activesupport/lib/active_support/notifications/fanout.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "mutex_m"
 require "concurrent/map"
 require "set"
 require "active_support/core_ext/object/try"
@@ -45,15 +44,13 @@ def iterate_guarding_exceptions(listeners)
     #
     # This class is thread safe. All methods are reentrant.
     class Fanout
-      include Mutex_m
-
       def initialize
+        @mutex = Mutex.new
         @string_subscribers = Concurrent::Map.new { |h, k| h.compute_if_absent(k) { [] } }
         @other_subscribers = []
         @all_listeners_for = Concurrent::Map.new
         @groups_for = Concurrent::Map.new
         @silenceable_groups_for = Concurrent::Map.new
-        super
       end
 
       def inspect # :nodoc:
@@ -63,7 +60,7 @@ def inspect # :nodoc:
 
       def subscribe(pattern = nil, callable = nil, monotonic: false, &block)
         subscriber = Subscribers.new(pattern, callable || block, monotonic)
-        synchronize do
+        @mutex.synchronize do
           case pattern
           when String
             @string_subscribers[pattern] << subscriber
@@ -79,7 +76,7 @@ def subscribe(pattern = nil, callable = nil, monotonic: false, &block)
       end
 
       def unsubscribe(subscriber_or_name)
-        synchronize do
+        @mutex.synchronize do
           case subscriber_or_name
           when String
             @string_subscribers[subscriber_or_name].clear
@@ -294,7 +291,7 @@ def publish_event(event)
 
       def all_listeners_for(name)
         # this is correctly done double-checked locking (Concurrent::Map's lookups have volatile semantics)
-        @all_listeners_for[name] || synchronize do
+        @all_listeners_for[name] || @mutex.synchronize do
           # use synchronisation when accessing @subscribers
           @all_listeners_for[name] ||=
             @string_subscribers[name] + @other_subscribers.select { |s| s.subscribed_to?(name) }