From 1c3b4f75d6aec9376cbcf6e6726f28a81b65b463 Mon Sep 17 00:00:00 2001
From: Jan Uhlig <juhlig@hnc-agency.org>
Date: Tue, 2 Jul 2024 18:22:39 +0200
Subject: [PATCH] Draft: stop_listener in ranch_server

---
 src/ranch.erl        | 38 +-------------------------------------
 src/ranch_server.erl | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 37 deletions(-)

diff --git a/src/ranch.erl b/src/ranch.erl
index d909afd735..3692f50414 100644
--- a/src/ranch.erl
+++ b/src/ranch.erl
@@ -193,43 +193,7 @@ start_error(_, Error) -> Error.
 
 -spec stop_listener(ref()) -> ok | {error, not_found}.
 stop_listener(Ref) ->
-	Parent = self(),
-	Tag = make_ref(),
-	{StopperPid, StopperMon} = spawn_monitor(fun() -> Parent ! {Tag, stop_listener1(Ref)} end),
-	receive
-		{Tag, Result} ->
-			demonitor(StopperMon, [flush]),
-			Result;
-		{'DOWN', StopperMon, process, StopperPid, Error} ->
-			{error, Error}
-	end.
-
-stop_listener1(Ref) ->
-	TransportAndOpts = maybe_get_transport_and_opts(Ref),
-	case supervisor:terminate_child(ranch_sup, {ranch_listener_sup, Ref}) of
-		ok ->
-			_ = supervisor:delete_child(ranch_sup, {ranch_listener_sup, Ref}),
-			ranch_server:cleanup_listener_opts(Ref),
-			stop_listener2(TransportAndOpts);
-		{error, _} = Error ->
-			Error
-	end.
-
-stop_listener2({Transport, TransOpts}) ->
-	Transport:cleanup(TransOpts),
-	ok;
-stop_listener2(undefined) ->
-	ok.
-
-maybe_get_transport_and_opts(Ref) ->
-	try
-		[_, Transport, _, _, _] = ranch_server:get_listener_start_args(Ref),
-		TransOpts = get_transport_options(Ref),
-		{Transport, TransOpts}
-	catch
-		error:badarg ->
-			undefined
-	end.
+	ranch_server:stop_listener(Ref).
 
 -spec suspend_listener(ref()) -> ok | {error, any()}.
 suspend_listener(Ref) ->
diff --git a/src/ranch_server.erl b/src/ranch_server.erl
index 3966c1b5a3..f590156f86 100644
--- a/src/ranch_server.erl
+++ b/src/ranch_server.erl
@@ -40,6 +40,7 @@
 -export([get_protocol_options/1]).
 -export([get_listener_start_args/1]).
 -export([count_connections/1]).
+-export([stop_listener/1]).
 
 %% gen_server.
 -export([init/1]).
@@ -180,6 +181,10 @@ count_connections(Ref) ->
 		0,
 		get_connections_sups(Ref)).
 
+-spec stop_listener(ranch:ref()) -> ok | {error, term()}.
+stop_listener(Ref) ->
+	gen_server:call(?MODULE, {stop_listener, Ref}).
+
 %% gen_server.
 
 -spec init([]) -> {ok, #state{}}.
@@ -220,6 +225,14 @@ handle_call({set_proto_opts, Ref, Opts}, _, State) ->
 	ets:insert(?TAB, {{proto_opts, Ref}, Opts}),
 	_ = [ConnsSup ! {set_protocol_options, Opts} || {_, ConnsSup} <- get_connections_sups(Ref)],
 	{reply, ok, State};
+handle_call({stop_listener, Ref}, _, State) ->
+	Reply = try
+		do_stop_listener(Ref)
+	catch
+		_:Reason ->
+			{error, Reason}
+	end,
+	{reply, Reply, State};
 handle_call(_Request, _From, State) ->
 	{reply, ignore, State}.
 
@@ -277,3 +290,33 @@ set_monitored_process(Key, Pid, State=#state{monitors=Monitors0}) ->
 	%% Finally we start monitoring this new process.
 	MonitorRef = erlang:monitor(process, Pid),
 	State#state{monitors=[{{MonitorRef, Pid}, Key}|Monitors]}.
+
+do_stop_listener(Ref) ->
+	do_stop_listener1(Ref).
+
+do_stop_listener1(Ref) ->
+	TransportAndOpts = try
+		[_, Transport, _, _, _] = get_listener_start_args(Ref),
+		TransOpts = get_transport_options(Ref),
+		{Transport, TransOpts}
+	catch
+		error:badarg ->
+			undefined
+	end,
+	do_stop_listener2(Ref, TransportAndOpts).
+
+do_stop_listener2(Ref, TransportAndOpts) ->
+	case supervisor:terminate_child(ranch_sup, {ranch_listener_sup, Ref}) of
+		ok ->
+			_ = supervisor:delete_child(ranch_sup, {ranch_listener_sup, Ref}),
+			_ = cleanup_listener_opts(Ref),
+			do_stop_listener3(TransportAndOpts);
+		{error, _} = Error ->
+			Error
+	end.
+
+do_stop_listener3(undefined) ->
+	ok;
+do_stop_listener3({Transport, TransOpts}) ->
+	_ = Transport:cleanup(TransOpts),
+	ok.