Enable usage of experimental inet_backend option for TCP listeners

Makefile

@@ -18,7 +18,7 @@ DOC_DEPS = asciideck
 
 TEST_DEPS = $(if $(CI_ERLANG_MK),ci.erlang.mk) ct_helper stampede
 dep_ct_helper = git https://github.com/ninenines/ct_helper master
-dep_stampede = git https://github.com/juhlig/stampede 0.5.0
+dep_stampede = git https://github.com/juhlig/stampede 0.6.0
 
 # Concuerror tests.
 

src/ranch_acceptors_sup.erl

@@ -60,12 +60,7 @@ start_listen_sockets(Ref, NumListenSockets, Transport, TransOpts0, Logger) when
 			[];
 		{_, Port} ->
 			SocketOpts = maps:get(socket_opts, TransOpts0, []),
-			SocketOpts1 = case lists:keyfind(port, 1, SocketOpts) of
-				{port, Port} ->
-					SocketOpts;
-				_ ->
-					[{port, Port}|lists:keydelete(port, 1, SocketOpts)]
-			end,
+			SocketOpts1 = lists:keystore(port, 1, SocketOpts, {port, Port}),
 			TransOpts1 = TransOpts0#{socket_opts => SocketOpts1},
 			[{N, start_listen_socket(Ref, Transport, TransOpts1, Logger)}
 				|| N <- lists:seq(2, NumListenSockets)]

src/ranch_tcp.erl

@@ -90,16 +90,24 @@ messages() -> {tcp, tcp_closed, tcp_error, tcp_passive}.
 listen(TransOpts) ->
 	ok = cleanup(TransOpts),
 	Logger = maps:get(logger, TransOpts, logger),
-	SocketOpts0 = maps:get(socket_opts, TransOpts, []),
+	SocketOpts = maps:get(socket_opts, TransOpts, []),
+	%% We set the port to 0 because it is given in the Opts directly.
+	%% The port in the options takes precedence over the one in the
+	%% first argument.
+	gen_tcp:listen(0, prepare_socket_opts(SocketOpts, Logger)).
+
+prepare_socket_opts([Backend = {inet_backend, _}|SocketOpts], Logger) ->
+	%% In OTP/23, the inet_backend option may be used to activate the
+	%% experimental socket backend for inet/gen_tcp. If present, it must
+	%% be the first option in the list.
+	[Backend|prepare_socket_opts(SocketOpts, Logger)];
+prepare_socket_opts(SocketOpts0, Logger) ->
 	SocketOpts1 = ranch:set_option_default(SocketOpts0, backlog, 1024),
 	SocketOpts2 = ranch:set_option_default(SocketOpts1, nodelay, true),
 	SocketOpts3 = ranch:set_option_default(SocketOpts2, send_timeout, 30000),
 	SocketOpts4 = ranch:set_option_default(SocketOpts3, send_timeout_close, true),
-	%% We set the port to 0 because it is given in the Opts directly.
-	%% The port in the options takes precedence over the one in the
-	%% first argument.
-	gen_tcp:listen(0, ranch:filter_options(SocketOpts4, disallowed_listen_options(),
-		[binary, {active, false}, {packet, raw}, {reuseaddr, true}], Logger)).
+	ranch:filter_options(SocketOpts4, disallowed_listen_options(),
+		[binary, {active, false}, {packet, raw}, {reuseaddr, true}], Logger).
 
 %% 'binary' and 'list' are disallowed but they are handled
 %% specifically as they do not have 2-tuple equivalents.