inets: Reverted commmit f97cd6965ac35d1cbe510de23592956857d144c8

The reverted commit took a too optimistic approch to pipeling. When added
we thought it would be an improvment, but it proved to be a
misconception.

3 files changed, 51 insertions, 45 deletions

diff --git a/lib/inets/src/http_client/httpc_handler.erl b/lib/inets/src/http_client/httpc_handler.erl
index a89a457a51..0957eb3261 100644
--- a/lib/inets/src/http_client/httpc_handler.erl
+++ b/lib/inets/src/http_client/httpc_handler.erl
@@ -1154,7 +1154,7 @@ handle_http_body(Body, #state{headers       = Headers,
 
 handle_response(#state{status = new} = State) ->
     ?hcrd("handle response - status = new", []),
-    handle_response(check_persistent(State));
+    handle_response(try_to_enable_pipeline_or_keep_alive(State));
 
 handle_response(#state{request      = Request,
 		       status       = Status,
@@ -1429,22 +1429,39 @@ is_keep_alive_enabled_server(_,_) ->
 is_keep_alive_connection(Headers, #session{client_close = ClientClose}) ->
     (not ((ClientClose) orelse httpc_response:is_server_closing(Headers))).
 
-check_persistent(
-  #state{session      = #session{type = Type} = Session, 
+try_to_enable_pipeline_or_keep_alive(
+  #state{session      = Session, 
+	 request      = #request{method = Method},
 	 status_line  = {Version, _, _},
 	 headers      = Headers,
-	 profile_name = ProfileName} = State) ->    
+	 profile_name = ProfileName} = State) ->
+    ?hcrd("try to enable pipeline or keep-alive", 
+	  [{version, Version}, 
+	   {headers, Headers}, 
+	   {session, Session}]),
     case is_keep_alive_enabled_server(Version, Headers) andalso 
-	is_keep_alive_connection(Headers, Session) of
+	  is_keep_alive_connection(Headers, Session) of
 	true ->
-	    mark_persistent(ProfileName, Session),
-	    State#state{status = Type};
+	    case (is_pipeline_enabled_client(Session) andalso 
+		  httpc_request:is_idempotent(Method)) of
+		true ->
+		    insert_session(Session, ProfileName),
+		    State#state{status = pipeline};
+		false ->
+		    insert_session(Session, ProfileName),
+		    %% Make sure type is keep_alive in session
+		    %% as it in this case might be pipeline
+		    NewSession = Session#session{type = keep_alive}, 
+		    State#state{status  = keep_alive,
+				session = NewSession}
+	    end;
 	false ->
 	    State#state{status = close}
     end.
 
 answer_request(#request{id = RequestId, from = From} = Request, Msg, 
-	       #state{timers       = Timers, 
+	       #state{session      = Session, 
+		      timers       = Timers, 
 		      profile_name = ProfileName} = State) -> 
     ?hcrt("answer request", [{request, Request}, {msg, Msg}]),
     httpc_response:send(From, Msg),
@@ -1454,14 +1471,19 @@ answer_request(#request{id = RequestId, from = From} = Request, Msg,
     Timer = {RequestId, TimerRef},
     cancel_timer(TimerRef, {timeout, Request#request.id}),
     httpc_manager:request_done(RequestId, ProfileName),
+    NewSession = maybe_make_session_available(ProfileName, Session), 
     Timers2 = Timers#timers{request_timers = lists:delete(Timer, 
 							  RequestTimers)}, 
     State#state{request = Request#request{from = answer_sent},
+		session = NewSession, 
 		timers  = Timers2}.
 
-mark_persistent(ProfileName, Session) ->
-    update_session(ProfileName, Session, #session.persistent, true),
-    Session#session{persistent = true}.
+maybe_make_session_available(ProfileName, 
+			     #session{available = false} = Session) ->
+    update_session(ProfileName, Session, #session.available, true),
+    Session#session{available = true};
+maybe_make_session_available(_ProfileName, Session) ->
+    Session.
     
 cancel_timers(#timers{request_timers = ReqTmrs, queue_timer = QTmr}) ->
     cancel_timer(QTmr, timeout_queue),
diff --git a/lib/inets/src/http_client/httpc_internal.hrl b/lib/inets/src/http_client/httpc_internal.hrl
index d5b3dd2a2a..add5d11dfa 100644
--- a/lib/inets/src/http_client/httpc_internal.hrl
+++ b/lib/inets/src/http_client/httpc_internal.hrl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2005-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2005-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -143,8 +143,8 @@
 
 	  %% true | false
 	  %% This will be true, when a response has been received for 
-	  %% the first request and the server has not closed the connection
-	  persistent = false
+	  %% the first request. See type above.
+	  available = false
 	 }).
 
 
diff --git a/lib/inets/src/http_client/httpc_manager.erl b/lib/inets/src/http_client/httpc_manager.erl
index a3ed371e61..48a9c32454 100644
--- a/lib/inets/src/http_client/httpc_manager.erl
+++ b/lib/inets/src/http_client/httpc_manager.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2002-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2002-2014. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -451,7 +451,7 @@ do_init(ProfileName, CookiesDir) ->
 %%--------------------------------------------------------------------
 handle_call({request, Request}, _, State) ->
     ?hcri("request", [{request, Request}]),
-    case (catch handle_request(Request, State, false)) of
+    case (catch handle_request(Request, State)) of
 	{reply, Msg, NewState} ->
 	    {reply, Msg, NewState};
 	Error ->
@@ -511,7 +511,7 @@ handle_cast({retry_or_redirect_request, {Time, Request}},
     {noreply, State};
 
 handle_cast({retry_or_redirect_request, Request}, State) ->
-    case (catch handle_request(Request, State, true)) of
+    case (catch handle_request(Request, State)) of
 	{reply, {ok, _}, NewState} ->
 	    {noreply, NewState};
 	Error  ->
@@ -724,7 +724,7 @@ get_handler_info(Tab) ->
 
 handle_request(#request{settings = 
 			#http_options{version = "HTTP/0.9"}} = Request,
-	       State, _) ->
+	       State) ->
     %% Act as an HTTP/0.9 client that does not know anything
     %% about persistent connections
 
@@ -737,7 +737,7 @@ handle_request(#request{settings =
 
 handle_request(#request{settings = 
 			#http_options{version = "HTTP/1.0"}} = Request,
-	       State, _) ->
+	       State) ->
     %% Act as an HTTP/1.0 client that does not
     %% use persistent connections
 
@@ -748,13 +748,13 @@ handle_request(#request{settings =
     start_handler(NewRequest#request{headers = NewHeaders}, State),
     {reply, {ok, NewRequest#request.id}, State};
 
-handle_request(Request, State = #state{options = Options}, Retry) ->
+handle_request(Request, State = #state{options = Options}) ->
 
     NewRequest = handle_cookies(generate_request_id(Request), State),
     SessionType = session_type(Options),
     case select_session(Request#request.method,
 			Request#request.address,
-			Request#request.scheme, SessionType, State, Retry) of
+			Request#request.scheme, SessionType, State) of
 	{ok, HandlerPid} ->
 	    pipeline_or_keep_alive(NewRequest, HandlerPid, State);
 	no_connection ->
@@ -778,7 +778,6 @@ start_handler(#request{id   = Id,
 	      #state{profile_name = ProfileName, 
 		     handler_db   = HandlerDb, 
 		     options      = Options}) ->
-    ClientClose = httpc_request:is_client_closing(Request#request.headers),
     {ok, Pid} =
 	case is_inets_manager() of
 	    true ->
@@ -789,18 +788,13 @@ start_handler(#request{id   = Id,
 	end,
     HandlerInfo = {Id, Pid, From}, 
     ets:insert(HandlerDb, HandlerInfo), 
-    insert_session(#session{id = {Request#request.address, Pid},
-			    scheme = Request#request.scheme,
-			    client_close = ClientClose,
-			    type = session_type(Options)
-			   }, ProfileName),
     erlang:monitor(process, Pid).
 
 
 select_session(Method, HostPort, Scheme, SessionType, 
 	       #state{options = #options{max_pipeline_length   = MaxPipe,
 					 max_keep_alive_length = MaxKeepAlive},
-		      session_db = SessionDb}, Retry) ->
+		      session_db = SessionDb}) ->
     ?hcrd("select session", [{session_type,          SessionType},
 			     {max_pipeline_length,   MaxPipe},
 			     {max_keep_alive_length, MaxKeepAlive}]),
@@ -813,23 +807,13 @@ select_session(Method, HostPort, Scheme, SessionType,
 	    %% client_close, scheme and type specified. 
 	    %% The fields id (part of: HandlerPid) and queue_length
 	    %% specified.
-	    Pattern = case (Retry andalso SessionType == pipeline) of
-			  true ->
-			      #session{id           = {HostPort, '$1'},
-				       client_close = false,
-				       scheme       = Scheme,
-				       queue_length = '$2',
-				       type         = SessionType,
-				       persistent   = true,
-				       _            = '_'};
-			  false ->
-			      #session{id           = {HostPort, '$1'},
-				       client_close = false,
-				       scheme       = Scheme,
-				       queue_length = '$2',
-				       type         = SessionType,
-				       _            = '_'}
-		      end,
+	    Pattern = #session{id           = {HostPort, '$1'},
+			       client_close = false,
+			       scheme       = Scheme,
+			       queue_length = '$2',
+			       type         = SessionType,
+			       available    = true, 
+			       _            = '_'},
 	    %% {'_', {HostPort, '$1'}, false, Scheme, '_', '$2', SessionTyp}, 
 	    Candidates = ets:match(SessionDb, Pattern), 
 	    ?hcrd("select session", [{host_port,  HostPort},