Deprecate config.threadsafe!

3 files changed, 14 insertions, 16 deletions

diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 851f41249a..fea18b5f47 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -5,6 +5,8 @@
     default_url_options[:script_name] to set proper application's mount point by
     yourself. *Piotr Sarnacki*
 
+*   `config.threadsafe!` is deprecated in favor of `config.eager_load` which provides a more fine grained control on what is eager loaded *José Valim*
+
 *   The migration generator will now produce AddXXXToYYY/RemoveXXXFromYYY migrations with references statements, for instance
 
         rails g migration AddReferencesToProducts user:references supplier:references{polymorphic}
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index 5c7cf412ac..7f05b2e7e1 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -90,11 +90,10 @@ module Rails
         end
       end
 
-      # Enable threaded mode. Allows concurrent requests to controller actions and
-      # multiple database connections. Also disables automatic dependency loading
-      # after boot, and disables reloading code on every request, as these are
-      # fundamentally incompatible with thread safety.
       def threadsafe!
+        ActiveSupport::Deprecation.warn "config.threadsafe! is deprecated. Rails applications " \
+          "behave by default as thread safe in production as long as config.cache_classes and " \
+          "config.eager_load are set to true"
         @cache_classes = true
         @eager_load = true
         self
diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index 26f8aad95b..ebdbbaee8b 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -139,23 +139,19 @@ module ApplicationTests
       assert_instance_of Pathname, Rails.root
     end
 
-    test "marking the application as threadsafe sets the correct config variables" do
+    test "initialize an eager loaded, cache classes app" do
       add_to_config <<-RUBY
-        config.threadsafe!
+        config.eager_load = true
+        config.cache_classes = true
       RUBY
 
       require "#{app_path}/config/application"
-      assert AppTemplate::Application.config.cache_classes
-      assert AppTemplate::Application.config.eager_load
+      assert AppTemplate::Application.initialize!
     end
 
-    test "initialize a threadsafe app" do
-      add_to_config <<-RUBY
-        config.threadsafe!
-      RUBY
-
+    test "application is always added to eager_load namespaces" do
       require "#{app_path}/config/application"
-      assert AppTemplate::Application.initialize!
+      assert AppTemplate::Application, AppTemplate::Application.config.eager_load_namespaces
     end
 
     test "asset_path defaults to nil for application" do
@@ -163,10 +159,11 @@ module ApplicationTests
       assert_equal nil, AppTemplate::Application.config.asset_path
     end
 
-    test "the application can be marked as threadsafe when there are no frameworks" do
+    test "the application can be eager loaded even when there are no frameworks" do
       FileUtils.rm_rf("#{app_path}/config/environments")
       add_to_config <<-RUBY
-        config.threadsafe!
+        config.eager_load = true
+        config.cache_classes = true
       RUBY
 
       use_frameworks []