From f21640d9dc52db974f7851f73d8c47775dd8f283 Mon Sep 17 00:00:00 2001
From: Hongli Lai (Phusion) <hongli@phusion.nl>
Date: Fri, 31 Jul 2009 15:35:53 +0200
Subject: [PATCH] Make the new code reloading behavior work with multi-threaded environments such as Mongrel. Fixes issues #2948 and #8994.

---
 actionpack/lib/action_controller/reloader.rb |   14 ++++++--
 actionpack/test/controller/reloader_test.rb  |   44 ++++++++++++++++++++++++-
 2 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/actionpack/lib/action_controller/reloader.rb b/actionpack/lib/action_controller/reloader.rb
index 459dece..9a9786b 100644
--- a/actionpack/lib/action_controller/reloader.rb
+++ b/actionpack/lib/action_controller/reloader.rb
@@ -1,14 +1,20 @@
+require 'thread'
+
 module ActionController
   class Reloader
+    @@lock = Mutex.new
+    
     class BodyWrapper
-      def initialize(body)
+      def initialize(body, lock)
         @body = body
+        @lock = lock
       end
 
       def close
         @body.close if @body.respond_to?(:close)
       ensure
         Dispatcher.cleanup_application
+        @lock.unlock
       end
 
       def method_missing(*args, &block)
@@ -20,11 +26,13 @@ module ActionController
       end
     end
 
-    def initialize(app)
+    def initialize(app, lock = @@lock)
       @app = app
+      @lock = lock
     end
 
     def call(env)
+      @lock.lock
       Dispatcher.reload_application
       status, headers, body = @app.call(env)
       # We do not want to call 'cleanup_application' in an ensure block
@@ -39,7 +47,7 @@ module ActionController
       # completely finished. So we wrap the body in a BodyWrapper class so that
       # when the Rack handler calls #close during the end of the request, we get to
       # run our cleanup code.
-      [status, headers, BodyWrapper.new(body)]
+      [status, headers, BodyWrapper.new(body, @lock)]
     end
   end
 end
diff --git a/actionpack/test/controller/reloader_test.rb b/actionpack/test/controller/reloader_test.rb
index 6f1f3c8..4631cce 100644
--- a/actionpack/test/controller/reloader_test.rb
+++ b/actionpack/test/controller/reloader_test.rb
@@ -21,10 +21,28 @@ class ReloaderTests < ActiveSupport::TestCase
       @on_close.call if @on_close
     end
   end
+  
+  class MyLock
+    def lock
+      @locked = true
+    end
+    
+    def unlock
+      @locked = false
+    end
+    
+    def locked?
+      @locked
+    end
+  end
+  
+  def setup
+    @lock = Mutex.new
+  end
 
   def setup_and_return_body(app = lambda { })
     Dispatcher.expects(:reload_application)
-    reloader = Reloader.new(app)
+    reloader = Reloader.new(app, @lock)
     headers, status, body = reloader.call({ })
     body
   end
@@ -33,9 +51,31 @@ class ReloaderTests < ActiveSupport::TestCase
     Dispatcher.expects(:reload_application)
     reloader = Reloader.new(lambda {
       [200, { "Content-Type" => "text/html" }, [""]]
-    })
+    }, @lock)
     reloader.call({ })
   end
+  
+  def test_it_locks_before_calling_app
+    lock = MyLock.new
+    Dispatcher.expects(:reload_application)
+    reloader = Reloader.new(lambda {
+      [200, { "Content-Type" => "text/html" }, [""]]
+    }, lock)
+    assert !lock.locked?
+    reloader.call({ })
+    assert lock.locked?
+  end
+  
+  def it_unlocks_upon_calling_close_on_body
+    lock = MyLock.new
+    Dispatcher.expects(:reload_application)
+    reloader = Reloader.new(lambda {
+      [200, { "Content-Type" => "text/html" }, [""]]
+    }, lock)
+    headers, status, body = reloader.call({ })
+    body.close
+    assert !lock.locked?
+  end
 
   def test_returned_body_object_always_responds_to_close
     body = setup_and_return_body(lambda {
-- 
1.6.0.5