[PATCH 3/4] http: remove the keepalive requests limit

[Eric Wong <e@80x24.org>]

This was a hack for some event loops such as those found in nginx
and some Rainbows! concurrency models.  Using epoll/kqueue with
one-shot notification (which yahns does) avoids all fairness
problems.
---
 ext/unicorn_http/unicorn_http.rl | 37 ++------------------
 test/unit/test_http_parser_ng.rb | 74 +---------------------------------------
 2 files changed, 3 insertions(+), 108 deletions(-)

diff --git a/ext/unicorn_http/unicorn_http.rl b/ext/unicorn_http/unicorn_http.rl
index ecdadb0..9372d39 100644
--- a/ext/unicorn_http/unicorn_http.rl
+++ b/ext/unicorn_http/unicorn_http.rl
@@ -29,29 +29,6 @@ void init_unicorn_httpdate(void);
 /* all of these flags need to be set for keepalive to be supported */
 #define UH_FL_KEEPALIVE (UH_FL_KAVERSION | UH_FL_REQEOF | UH_FL_HASHEADER)
 
-static unsigned long keepalive_requests = 100; /* same as nginx */
-
-/*
- * Returns the maximum number of keepalive requests a client may make
- * before the parser refuses to continue.
- */
-static VALUE ka_req(VALUE self)
-{
-  return ULONG2NUM(keepalive_requests);
-}
-
-/*
- * Sets the maximum number of keepalive requests a client may make.
- * A special value of +nil+ causes this to be the maximum value
- * possible (this is architecture-dependent).
- */
-static VALUE set_ka_req(VALUE self, VALUE val)
-{
-  keepalive_requests = NIL_P(val) ? ULONG_MAX : NUM2ULONG(val);
-
-  return ka_req(self);
-}
-
 static size_t MAX_HEADER_LEN = 1024 * (80 + 32); /* same as Mongrel */
 
 /* this is only intended for use with Rainbows! */
@@ -64,7 +41,6 @@ static VALUE set_maxhdrlen(VALUE self, VALUE len)
 struct http_parser {
   int cs; /* Ragel internal state */
   unsigned int flags;
-  unsigned long nr_requests;
   size_t mark;
   size_t offset;
   union { /* these 2 fields don't nest */
@@ -580,7 +556,6 @@ static VALUE HttpParser_init(VALUE self)
   http_parser_init(hp);
   hp->buf = rb_str_new(NULL, 0);
   hp->env = rb_hash_new();
-  hp->nr_requests = keepalive_requests;
 
   return self;
 }
@@ -814,15 +789,13 @@ static VALUE HttpParser_keepalive(VALUE self)
  *    parser.next? => true or false
  *
  * Exactly like HttpParser#keepalive?, except it will reset the internal
- * parser state on next parse if it returns true.  It will also respect
- * the maximum *keepalive_requests* value and return false if that is
- * reached.
+ * parser state on next parse if it returns true.
  */
 static VALUE HttpParser_next(VALUE self)
 {
   struct http_parser *hp = data_get(self);
 
-  if ((HP_FL_ALL(hp, KEEPALIVE)) && (hp->nr_requests-- != 0)) {
+  if (HP_FL_ALL(hp, KEEPALIVE)) {
     HP_FL_SET(hp, TO_CLEAR);
     return Qtrue;
   }
@@ -984,12 +957,6 @@ void Init_unicorn_http(void)
    */
   rb_define_const(cHttpParser, "LENGTH_MAX", OFFT2NUM(UH_OFF_T_MAX));
 
-  /* default value for keepalive_requests */
-  rb_define_const(cHttpParser, "KEEPALIVE_REQUESTS_DEFAULT",
-                  ULONG2NUM(keepalive_requests));
-
-  rb_define_singleton_method(cHttpParser, "keepalive_requests", ka_req, 0);
-  rb_define_singleton_method(cHttpParser, "keepalive_requests=", set_ka_req, 1);
   rb_define_singleton_method(cHttpParser, "max_header_len=", set_maxhdrlen, 1);
 
   init_common_fields();
diff --git a/test/unit/test_http_parser_ng.rb b/test/unit/test_http_parser_ng.rb
index ab335ac..9167845 100644
--- a/test/unit/test_http_parser_ng.rb
+++ b/test/unit/test_http_parser_ng.rb
@@ -8,7 +8,6 @@ include Unicorn
 class HttpParserNgTest < Test::Unit::TestCase
 
   def setup
-    HttpParser.keepalive_requests = HttpParser::KEEPALIVE_REQUESTS_DEFAULT
     @parser = HttpParser.new
   end
 
@@ -29,25 +28,6 @@ class HttpParserNgTest < Test::Unit::TestCase
     assert_equal false, @parser.response_start_sent
   end
 
-  def test_keepalive_requests_default_constant
-    assert_kind_of Integer, HttpParser::KEEPALIVE_REQUESTS_DEFAULT
-    assert HttpParser::KEEPALIVE_REQUESTS_DEFAULT >= 0
-  end
-
-  def test_keepalive_requests_setting
-    HttpParser.keepalive_requests = 0
-    assert_equal 0, HttpParser.keepalive_requests
-    HttpParser.keepalive_requests = nil
-    assert HttpParser.keepalive_requests >= 0xffffffff
-    HttpParser.keepalive_requests = 1
-    assert_equal 1, HttpParser.keepalive_requests
-    HttpParser.keepalive_requests = 666
-    assert_equal 666, HttpParser.keepalive_requests
-
-    assert_raises(TypeError) { HttpParser.keepalive_requests = "666" }
-    assert_raises(TypeError) { HttpParser.keepalive_requests = [] }
-  end
-
   def test_connection_TE
     @parser.buf << "GET / HTTP/1.1\r\nHost: example.com\r\nConnection: TE\r\n"
     @parser.buf << "TE: trailers\r\n\r\n"
@@ -71,41 +51,11 @@ class HttpParserNgTest < Test::Unit::TestCase
       "REQUEST_METHOD" => "GET",
       "QUERY_STRING" => ""
     }.freeze
-    HttpParser::KEEPALIVE_REQUESTS_DEFAULT.times do |nr|
-      @parser.buf << req
-      assert_equal expect, @parser.parse
-      assert @parser.next?
-    end
-    @parser.buf << req
-    assert_equal expect, @parser.parse
-    assert ! @parser.next?
-  end
-
-  def test_fewer_keepalive_requests_with_next?
-    HttpParser.keepalive_requests = 5
-    @parser = HttpParser.new
-    req = "GET / HTTP/1.1\r\nHost: example.com\r\n\r\n".freeze
-    expect = {
-      "SERVER_NAME" => "example.com",
-      "HTTP_HOST" => "example.com",
-      "rack.url_scheme" => "http",
-      "REQUEST_PATH" => "/",
-      "SERVER_PROTOCOL" => "HTTP/1.1",
-      "PATH_INFO" => "/",
-      "HTTP_VERSION" => "HTTP/1.1",
-      "REQUEST_URI" => "/",
-      "SERVER_PORT" => "80",
-      "REQUEST_METHOD" => "GET",
-      "QUERY_STRING" => ""
-    }.freeze
-    5.times do |nr|
+    100.times do |nr|
       @parser.buf << req
       assert_equal expect, @parser.parse
       assert @parser.next?
     end
-    @parser.buf << req
-    assert_equal expect, @parser.parse
-    assert ! @parser.next?
   end
 
   def test_default_keepalive_is_off
@@ -664,28 +614,6 @@ class HttpParserNgTest < Test::Unit::TestCase
     assert_equal "", @parser.buf
   end
 
-  def test_keepalive_requests_disabled
-    req = "GET / HTTP/1.1\r\nHost: example.com\r\n\r\n".freeze
-    expect = {
-      "SERVER_NAME" => "example.com",
-      "HTTP_HOST" => "example.com",
-      "rack.url_scheme" => "http",
-      "REQUEST_PATH" => "/",
-      "SERVER_PROTOCOL" => "HTTP/1.1",
-      "PATH_INFO" => "/",
-      "HTTP_VERSION" => "HTTP/1.1",
-      "REQUEST_URI" => "/",
-      "SERVER_PORT" => "80",
-      "REQUEST_METHOD" => "GET",
-      "QUERY_STRING" => ""
-    }.freeze
-    HttpParser.keepalive_requests = 0
-    @parser = HttpParser.new
-    @parser.buf << req
-    assert_equal expect, @parser.parse
-    assert ! @parser.next?
-  end
-
   def test_chunk_only
     tmp = ""
     assert_equal @parser, @parser.dechunk!
-- 
EW