1 files changed, 29 insertions, 25 deletions

diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index fc20e7a421..26a16104db 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -1,9 +1,9 @@
-require 'action_dispatch/http/response'
-require 'delegate'
-require 'active_support/json'
+require "action_dispatch/http/response"
+require "delegate"
+require "active_support/json"
 
 module ActionController
-  # Mix this module in to your controller, and all actions in that controller
+  # Mix this module into your controller, and all actions in that controller
   # will be able to stream data to the client as it's written.
   #
   #   class MyController < ActionController::Base
@@ -20,7 +20,7 @@ module ActionController
   #     end
   #   end
   #
-  # There are a few caveats with this use. You *cannot* write headers after the
+  # There are a few caveats with this module. You *cannot* write headers after the
   # response has been committed (Response#committed? will return truthy).
   # Calling +write+ or +close+ on the response stream will cause the response
   # object to be committed. Make sure all headers are set before calling write
@@ -84,7 +84,6 @@ module ActionController
     # Note: SSEs are not currently supported by IE. However, they are supported
     # by Chrome, Firefox, Opera, and Safari.
     class SSE
-
       WHITELISTED_OPTIONS = %w( retry event id )
 
       def initialize(stream, options = {})
@@ -163,14 +162,6 @@ module ActionController
         end
       end
 
-      def each
-        @response.sending!
-        while str = @buf.pop
-          yield str
-        end
-        @response.sent!
-      end
-
       # Write a 'close' event to the buffer; the producer/writing thread
       # uses this to notify us that it's finished supplying content.
       #
@@ -210,23 +201,36 @@ module ActionController
       def call_on_error
         @error_callback.call
       end
+
+      private
+
+        def each_chunk(&block)
+          loop do
+            str = nil
+            ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
+              str = @buf.pop
+            end
+            break unless str
+            yield str
+          end
+        end
     end
 
     class Response < ActionDispatch::Response #:nodoc: all
       private
 
-      def before_committed
-        super
-        jar = request.cookie_jar
-        # The response can be committed multiple times
-        jar.write self unless committed?
-      end
+        def before_committed
+          super
+          jar = request.cookie_jar
+          # The response can be committed multiple times
+          jar.write self unless committed?
+        end
 
-      def build_buffer(response, body)
-        buf = Live::Buffer.new response
-        body.each { |part| buf.write part }
-        buf
-      end
+        def build_buffer(response, body)
+          buf = Live::Buffer.new response
+          body.each { |part| buf.write part }
+          buf
+        end
     end
 
     def process(name)