Merge pull request #12398 from thedarkone/thread-safety-stuff

Thread safety fixes

actionpack/lib/action_dispatch/journey/gtg/transition_table.rb

@@ -9,8 +9,8 @@ module ActionDispatch
         attr_reader :memos
 
         def initialize
-          @regexp_states = Hash.new { |h,k| h[k] = {} }
-          @string_states = Hash.new { |h,k| h[k] = {} }
+          @regexp_states = {}
+          @string_states = {}
           @accepting     = {}
           @memos         = Hash.new { |h,k| h[k] = [] }
         end
@@ -111,14 +111,8 @@ module ActionDispatch
         end
 
         def []=(from, to, sym)
-          case sym
-          when String
-            @string_states[from][sym] = to
-          when Regexp
-            @regexp_states[from][sym] = to
-          else
-            raise ArgumentError, 'unknown symbol: %s' % sym.class
-          end
+          to_mappings = states_hash_for(sym)[from] ||= {}
+          to_mappings[sym] = to
         end
 
         def states
@@ -137,18 +131,35 @@ module ActionDispatch
 
         private
 
+          def states_hash_for(sym)
+            case sym
+            when String
+              @string_states
+            when Regexp
+              @regexp_states
+            else
+              raise ArgumentError, 'unknown symbol: %s' % sym.class
+            end
+          end
+
           def move_regexp(t, a)
             return [] if t.empty?
 
             t.map { |s|
-              @regexp_states[s].map { |re, v| re === a ? v : nil }
+              if states = @regexp_states[s]
+                states.map { |re, v| re === a ? v : nil }
+              end
             }.flatten.compact.uniq
           end
 
           def move_string(t, a)
             return [] if t.empty?
 
-            t.map { |s| @string_states[s][a] }.compact
+            t.map do |s|
+              if states = @string_states[s]
+                states[a]
+              end
+            end.compact
           end
       end
     end

actionpack/lib/action_dispatch/journey/visitors.rb

@@ -1,9 +1,12 @@
 # encoding: utf-8
+
+require 'thread_safe'
+
 module ActionDispatch
   module Journey # :nodoc:
     module Visitors # :nodoc:
       class Visitor # :nodoc:
-        DISPATCH_CACHE = Hash.new { |h,k|
+        DISPATCH_CACHE = ThreadSafe::Cache.new { |h,k|
           h[k] = :"visit_#{k}"
         }
 

activerecord/lib/active_record/attribute_methods.rb

@@ -1,5 +1,6 @@
 require 'active_support/core_ext/enumerable'
 require 'mutex_m'
+require 'thread_safe'
 
 module ActiveRecord
   # = Active Record Attribute Methods
@@ -29,23 +30,18 @@ module ActiveRecord
     }
 
     class AttributeMethodCache
-      include Mutex_m
-
       def initialize
-        super
         @module = Module.new
-        @method_cache = {}
+        @method_cache = ThreadSafe::Cache.new
       end
 
       def [](name)
-        synchronize do
-          @method_cache.fetch(name) {
-            safe_name = name.unpack('h*').first
-            temp_method = "__temp__#{safe_name}"
-            ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
-            @module.module_eval method_body(temp_method, safe_name), __FILE__, __LINE__
-            @method_cache[name] = @module.instance_method temp_method
-          }
+        @method_cache.compute_if_absent(name) do
+          safe_name = name.unpack('h*').first
+          temp_method = "__temp__#{safe_name}"
+          ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
+          @module.module_eval method_body(temp_method, safe_name), __FILE__, __LINE__
+          @module.instance_method temp_method
         end
       end