http: move response_start_sent into the C ext

Combined with the previous commit to eliminate the `@socket'
instance variable, this eliminates the last instance variable
in the Unicorn::HttpRequest class.

Eliminating the last instance variable avoids the creation of a
internal hash table used for implementing the "generic" instance
variables found in non-pure-Ruby classes.  Method entry overhead
remains the same.

While this change doesn't do a whole lot for unicorn memory usage
where the HttpRequest is a singleton, it helps other HTTP servers
which rely on this code where thousands of clients may be connected.

1 files changed, 1 insertions, 3 deletions

diff --git a/lib/unicorn/http_request.rb b/lib/unicorn/http_request.rb
index f5c6b5b..9339bce 100644
--- a/lib/unicorn/http_request.rb
+++ b/lib/unicorn/http_request.rb
@@ -25,8 +25,6 @@ class Unicorn::HttpParser
   RACK_HIJACK_IO = "rack.hijack_io".freeze
   NULL_IO = StringIO.new("")
 
-  attr_accessor :response_start_sent
-
   # :stopdoc:
   # A frozen format for this is about 15% faster
   # Drop these frozen strings when Ruby 2.2 becomes more prevalent,
@@ -92,7 +90,7 @@ class Unicorn::HttpParser
 
     # detect if the socket is valid by writing a partial response:
     if @@check_client_connection && headers?
-      @response_start_sent = true
+      self.response_start_sent = true
       HTTP_RESPONSE_START.each { |c| socket.write(c) }
     end