adstage-david · January 30, 2015 21:57 · Jan 30, 2015 · Nov 14, 2011
diff --git a/gistfile1.rb b/gistfile1.rb
@@ -29,3 +29,6 @@ def thread_connected?
   class ImplicitConnectionForbiddenError < ActiveRecord::ConnectionTimeoutError ; end
 
 end
+
+ActiveRecord::Base.forbid_implicit_checkout_for_thread!
+ActiveRecord::Base.connection_pool.checkin(ActiveRecord::Base.connection_pool.connections.first)
diff --git a/gistfile1.rb b/gistfile1.rb
@@ -0,0 +1,31 @@
+# Call ActiveRecord::base.forbid_implicit_checkout_for_thread! from a thread, and if
+# that thread later tries to access an active record connection without explicit checkout
+# (#with_connection, or #checkout), an ImplicitConnectionForbiddenError will be raised. 
+
+module ActiveRecord
+  class Base
+    class << self
+      def forbid_implicit_checkout_for_thread!
+        Thread.current[:active_record_forbid_implicit_connections] = true
+      end
+
+      def connection
+        if Thread.current[:active_record_forbid_implicit_connections] && ! thread_connected?
+          raise ImplicitConnectionForbiddenError.new("Implicit ActiveRecord checkout attempted when Thread :force_explicit_connections set!")
+        end
+        retrieve_connection
+      end
+
+      # In Rails 3.1, this is connection_pool.active_connection? 
+      # But we define our own so we have it in Rails 3.0 too. 
+      def thread_connected?
+        connection_id = connection_pool.send(:current_connection_id)
+        connection_pool.instance_variable_get("@reserved_connections").has_key? connection_id
+      end
+
+    end           
+  end  
+
+  class ImplicitConnectionForbiddenError < ActiveRecord::ConnectionTimeoutError ; end
+
+end