Convert a few classes to be more thread-safe

app/services/phone_number_capabilities.rb

@@ -11,20 +11,29 @@ def self.load_config
 
   attr_reader :phone, :phone_confirmed
 
-  def self.translated_international_codes
-    @translated_intl_codes_data = nil if Rails.env.development?
-    return @translated_intl_codes_data[I18n.locale] if @translated_intl_codes_data
-
-    @translated_intl_codes_data = Hash.new { |h, k| h[k] = {} }
+  def self.generate_translated_international_codes_data
+    translated_intl_codes_data = Hash.new { |h, k| h[k] = {} }
     I18n.available_locales.each do |locale|
       INTERNATIONAL_CODES.each do |k, value|
-        @translated_intl_codes_data[locale][k] =
+        translated_intl_codes_data[locale][k] =
           value.merge('name' => I18n.t("countries.#{k.downcase}", locale: locale))
       end
     end
-    @translated_intl_codes_data[I18n.locale]
+    translated_intl_codes_data
   end
 
+  def self.translated_international_codes
+    translated_intl_codes_data = if Rails.env.development?
+                                   generate_translated_international_codes_data
+                                 else
+                                   TRANSLATED_INTL_CODES_DATA
+                                 end
+
+    translated_intl_codes_data[I18n.locale] if translated_intl_codes_data
+  end
+
+  TRANSLATED_INTL_CODES_DATA = generate_translated_international_codes_data
+
   def initialize(phone, phone_confirmed:)
     @phone = phone
     @phone_confirmed = phone_confirmed

app/services/profanity_detector.rb

@@ -20,27 +20,18 @@ def without_profanity(limit: 1_000)
   # ProfanityFilter::Base.profane? splits by word, but this
   # checks all substrings
   def profane?(str)
-    preprocess_if_needed!
-
     str_no_whitespace = str.gsub(/\W/, '').downcase
 
-    (min_profanity_length..[str_no_whitespace.length, max_profanity_length].min).each do |size|
-      profane_regex = @regex_by_length[size]
+    (MIN_PROFANITY_LENGTH..[str_no_whitespace.length, MAX_PROFANITY_LENGTH].min).each do |size|
+      profane_regex = REGEX_BY_LENGTH[size]
       next if profane_regex.nil?
       return true if profane_regex.match?(str_no_whitespace)
     end
 
     false
   end
 
-  class << self
-    attr_reader :min_profanity_length
-    attr_reader :max_profanity_length
-  end
-
-  def preprocess_if_needed!
-    return if @preprocessed
-
+  def self.preprocess_lengths!
     # Map of {Integer => Set<string>}
     profanity_by_length = Hash.new { |h, k| h[k] = Set.new }
 
@@ -49,15 +40,17 @@ def preprocess_if_needed!
     end
 
     # Map of {Integer => Regexp}
-    @regex_by_length = Hash.new
+    regex_by_length = Hash.new
 
     profanity_by_length.each do |k, v|
       escaped = v.to_a.map { |x| Regexp.escape(x) }
-      @regex_by_length[k] = Regexp.new("(#{escaped.join('|')})")
+      regex_by_length[k] = Regexp.new("(#{escaped.join('|')})")
     end
 
-    @min_profanity_length, @max_profanity_length = profanity_by_length.keys.minmax
+    min_profanity_length, max_profanity_length = profanity_by_length.keys.minmax
 
-    @preprocessed = true
+    return [regex_by_length, min_profanity_length, max_profanity_length]
   end
+
+  REGEX_BY_LENGTH, MIN_PROFANITY_LENGTH, MAX_PROFANITY_LENGTH = self.preprocess_lengths!
 end

app/services/saml_endpoint.rb

@@ -10,7 +10,7 @@ def self.suffixes
   end
 
   def self.endpoint_configs
-    @endpoint_configs ||= IdentityConfig.store.saml_endpoint_configs
+    IdentityConfig.store.saml_endpoint_configs
   end
 
   def secret_key

config/initializers/rack_timeout.rb

@@ -11,10 +11,6 @@ class Timeout
       [path] + Idp::Constants::AVAILABLE_LOCALES.map { |locale| "/#{locale}#{path}" }
     end + ['/api/verify/images']
 
-    class << self
-      attr_accessor :excludes
-    end
-
     def call_with_excludes(env)
       if EXCLUDES.any? { |path| env['REQUEST_URI']&.start_with?(path) }
         @app.call(env)

lib/aws/ses.rb

@@ -4,8 +4,6 @@
 module Aws
   module SES
     class Base
-      cattr_accessor :region_pool
-
       def initialize(*); end
 
       def deliver(mail)