Add a test for websocket hibernate + timeout and fix this use case

The issue was that we were calling erlang:hibernate before a
receive .. after .. end call. Erlang hibernates the process before
reaching the receive instruction and we therefore couldn't enter
the after clause when hibernating.

This is now fixed by using erlang:send_after instead and receiving
that message instead of using an after clause.

1 files changed, 20 insertions, 5 deletions

diff --git a/src/cowboy_http_websocket.erl b/src/cowboy_http_websocket.erl
index 74c5d7a..3ffe35e 100644
--- a/src/cowboy_http_websocket.erl
+++ b/src/cowboy_http_websocket.erl
@@ -52,6 +52,7 @@
 	opts :: any(),
 	challenge = undefined :: undefined | binary(),
 	timeout = infinity :: timeout(),
+	timeout_ref = undefined :: undefined | reference(),
 	messages = undefined :: undefined | {atom(), atom(), atom()},
 	hibernate = false :: boolean(),
 	eop :: undefined | tuple(), %% hixie-76 specific.
@@ -170,16 +171,28 @@ handler_before_loop(State=#state{hibernate=true},
 		Req=#http_req{socket=Socket, transport=Transport},
 		HandlerState, SoFar) ->
 	Transport:setopts(Socket, [{active, once}]),
-	erlang:hibernate(?MODULE, handler_loop, [State#state{hibernate=false},
+	State2 = handler_loop_timeout(State),
+	erlang:hibernate(?MODULE, handler_loop, [State2#state{hibernate=false},
 		Req, HandlerState, SoFar]);
 handler_before_loop(State, Req=#http_req{socket=Socket, transport=Transport},
 		HandlerState, SoFar) ->
 	Transport:setopts(Socket, [{active, once}]),
-	handler_loop(State, Req, HandlerState, SoFar).
+	State2 = handler_loop_timeout(State),
+	handler_loop(State2, Req, HandlerState, SoFar).
+
+-spec handler_loop_timeout(#state{}) -> #state{}.
+handler_loop_timeout(State=#state{timeout=infinity}) ->
+	State#state{timeout_ref=undefined};
+handler_loop_timeout(State=#state{timeout=Timeout, timeout_ref=PrevRef}) ->
+	_ = case PrevRef of undefined -> ignore; PrevRef ->
+		erlang:cancel_timer(PrevRef) end,
+	TRef = make_ref(),
+	erlang:send_after(Timeout, self(), {?MODULE, timeout, TRef}),
+	State#state{timeout_ref=TRef}.
 
 %% @private
 -spec handler_loop(#state{}, #http_req{}, any(), binary()) -> ok.
-handler_loop(State=#state{messages={OK, Closed, Error}, timeout=Timeout},
+handler_loop(State=#state{messages={OK, Closed, Error}, timeout_ref=TRef},
 		Req=#http_req{socket=Socket}, HandlerState, SoFar) ->
 	receive
 		{OK, Socket, Data} ->
@@ -189,11 +202,13 @@ handler_loop(State=#state{messages={OK, Closed, Error}, timeout=Timeout},
 			handler_terminate(State, Req, HandlerState, {error, closed});
 		{Error, Socket, Reason} ->
 			handler_terminate(State, Req, HandlerState, {error, Reason});
+		{?MODULE, timeout, TRef} ->
+			websocket_close(State, Req, HandlerState, {normal, timeout});
+		{?MODULE, timeout, OlderTRef} when is_reference(OlderTRef) ->
+			handler_loop(State, Req, HandlerState, SoFar);
 		Message ->
 			handler_call(State, Req, HandlerState,
 				SoFar, websocket_info, Message, fun handler_before_loop/4)
-	after Timeout ->
-		websocket_close(State, Req, HandlerState, {normal, timeout})
 	end.
 
 -spec websocket_data(#state{}, #http_req{}, any(), binary()) -> ok.