1 files changed, 48 insertions, 37 deletions

diff --git a/activesupport/lib/active_support/cache/strategy/local_cache.rb b/activesupport/lib/active_support/cache/strategy/local_cache.rb
index db5f228a70..fb42c4a41e 100644
--- a/activesupport/lib/active_support/cache/strategy/local_cache.rb
+++ b/activesupport/lib/active_support/cache/strategy/local_cache.rb
@@ -8,6 +8,23 @@ module ActiveSupport
       # duration of a block. Repeated calls to the cache for the same key will hit the
       # in-memory cache for faster access.
       module LocalCache
+        # Class for storing and registering the local caches.
+        class LocalCacheRegistry # :nodoc:
+          extend ActiveSupport::PerThreadRegistry
+
+          def initialize
+            @registry = {}
+          end
+
+          def cache_for(local_cache_key)
+            @registry[local_cache_key]
+          end
+
+          def set_cache_for(local_cache_key, value)
+            @registry[local_cache_key] = value
+          end
+        end
+
         # Simple memory backed cache. This cache is not thread safe and is intended only
         # for serving as a temporary memory cache for a single thread.
         class LocalStore < Store
@@ -41,24 +58,18 @@ module ActiveSupport
 
         # Use a local cache for the duration of block.
         def with_local_cache
-          save_val = Thread.current[thread_local_key]
-          begin
-            Thread.current[thread_local_key] = LocalStore.new
-            yield
-          ensure
-            Thread.current[thread_local_key] = save_val
-          end
+          use_temporary_local_cache(LocalStore.new) { yield }
         end
 
         #--
         # This class wraps up local storage for middlewares. Only the middleware method should
         # construct them.
         class Middleware # :nodoc:
-          attr_reader :name, :thread_local_key
+          attr_reader :name, :local_cache_key
 
-          def initialize(name, thread_local_key)
+          def initialize(name, local_cache_key)
             @name             = name
-            @thread_local_key = thread_local_key
+            @local_cache_key = local_cache_key
             @app              = nil
           end
 
@@ -68,10 +79,10 @@ module ActiveSupport
           end
 
           def call(env)
-            Thread.current[thread_local_key] = LocalStore.new
+            LocalCacheRegistry.set_cache_for(local_cache_key, LocalStore.new)
             @app.call(env)
           ensure
-            Thread.current[thread_local_key] = nil
+            LocalCacheRegistry.set_cache_for(local_cache_key, nil)
           end
         end
 
@@ -80,7 +91,7 @@ module ActiveSupport
         def middleware
           @middleware ||= Middleware.new(
             "ActiveSupport::Cache::Strategy::LocalCache",
-            thread_local_key)
+            local_cache_key)
         end
 
         def clear(options = nil) # :nodoc:
@@ -95,29 +106,13 @@ module ActiveSupport
 
         def increment(name, amount = 1, options = nil) # :nodoc:
           value = bypass_local_cache{super}
-          if local_cache
-            local_cache.mute do
-              if value
-                local_cache.write(name, value, options)
-              else
-                local_cache.delete(name, options)
-              end
-            end
-          end
+          increment_or_decrement(value, name, amount, options)
           value
         end
 
         def decrement(name, amount = 1, options = nil) # :nodoc:
           value = bypass_local_cache{super}
-          if local_cache
-            local_cache.mute do
-              if value
-                local_cache.write(name, value, options)
-              else
-                local_cache.delete(name, options)
-              end
-            end
-          end
+          increment_or_decrement(value, name, amount, options)
           value
         end
 
@@ -146,21 +141,37 @@ module ActiveSupport
           end
 
         private
-          def thread_local_key
-            @thread_local_key ||= "#{self.class.name.underscore}_local_cache_#{object_id}".gsub(/[\/-]/, '_').to_sym
+          def increment_or_decrement(value, name, amount, options)
+            if local_cache
+              local_cache.mute do
+                if value
+                  local_cache.write(name, value, options)
+                else
+                  local_cache.delete(name, options)
+                end
+              end
+            end
+          end
+
+          def local_cache_key
+            @local_cache_key ||= "#{self.class.name.underscore}_local_cache_#{object_id}".gsub(/[\/-]/, '_').to_sym
           end
 
           def local_cache
-            Thread.current[thread_local_key]
+            LocalCacheRegistry.cache_for(local_cache_key)
           end
 
           def bypass_local_cache
-            save_cache = Thread.current[thread_local_key]
+            use_temporary_local_cache(nil) { yield }
+          end
+
+          def use_temporary_local_cache(temporary_cache)
+            save_cache = LocalCacheRegistry.cache_for(local_cache_key)
             begin
-              Thread.current[thread_local_key] = nil
+              LocalCacheRegistry.set_cache_for(local_cache_key, temporary_cache)
               yield
             ensure
-              Thread.current[thread_local_key] = save_cache
+              LocalCacheRegistry.set_cache_for(local_cache_key, save_cache)
             end
           end
       end