Return processing lock to dispatcher, the finer grained lock was incompatible with the reloading in development mode.

This commit also adds ActionController::Dispatcher#dispatch_unlocking -- non-locking version of dispatch.
It's named anologously to POSIX {getc,getchar,...}_unlocked functions.

Signed-off-by: Michael Koziarski <michael@koziarski.com>
[#1170 state:committed]

actionpack/lib/action_controller/base.rb

@@ -290,8 +290,6 @@ module ActionController #:nodoc:
     @@allow_concurrency = false
     cattr_accessor :allow_concurrency
 
-    @@guard = Monitor.new
-
     # Modern REST web services often need to submit complex data to the web application.
     # The <tt>@@param_parsers</tt> hash lets you register handlers which will process the HTTP body and add parameters to the
     # <tt>params</tt> hash. These handlers are invoked for POST and PUT requests.
@@ -532,12 +530,7 @@ module ActionController #:nodoc:
         assign_names
 
         log_processing
-
-        if @@allow_concurrency
-          send(method, *arguments)
-        else
-          @@guard.synchronize { send(method, *arguments) }
-        end
+        send(method, *arguments)
 
         send_response
       ensure

actionpack/lib/action_controller/dispatcher.rb

@@ -2,6 +2,8 @@ module ActionController
   # Dispatches requests to the appropriate controller and takes care of
   # reloading the app after each request when Dependencies.load? is true.
   class Dispatcher
+    @@guard = Mutex.new
+
     class << self
       def define_dispatcher_callbacks(cache_classes)
         unless cache_classes
@@ -99,7 +101,7 @@ module ActionController
       @output, @request, @response = output, request, response
     end
 
-    def dispatch
+    def dispatch_unlocked
       begin
         run_callbacks :before_dispatch
         handle_request
@@ -110,6 +112,16 @@ module ActionController
       end
     end
 
+    def dispatch
+      if ActionController::Base.allow_concurrency
+        dispatch_unlocked
+      else
+        @@guard.synchronize do
+          dispatch_unlocked
+        end
+      end
+    end
+
     def dispatch_cgi(cgi, session_options)
       if cgi ||= self.class.failsafe_response(@output, '400 Bad Request') { CGI.new }
         @request = CgiRequest.new(cgi, session_options)