chore(exproto): start idle timer for udp clients

apps/emqx_exproto/src/emqx_exproto_channel.erl

@@ -76,7 +76,8 @@
 
 -define(TIMER_TABLE, #{
           alive_timer => keepalive,
-          force_timer => force_close
+          force_timer => force_close,
+          idle_timer => force_close_idle
          }).
 
 -define(INFO_KEYS, [conninfo, conn_state, clientinfo, session, will_msg]).
@@ -94,6 +95,8 @@
          awaiting_rel_max
         ]).
 
+-define(DEFAULT_IDLE_TIMEOUT, 30000).
+
 %%--------------------------------------------------------------------
 %% Info, Attrs and Caps
 %%--------------------------------------------------------------------
@@ -149,8 +152,12 @@ init(ConnInfo = #{socktype := Socktype,
     GRpcChann = proplists:get_value(handler, Options),
     NConnInfo = default_conninfo(ConnInfo),
     ClientInfo = default_clientinfo(ConnInfo),
+
+    IdleTimeout = proplists:get_value(idle_timeout, Options, ?DEFAULT_IDLE_TIMEOUT),
+
+    NConnInfo1 = NConnInfo#{idle_timeout => IdleTimeout},
     Channel = #channel{gcli = #{channel => GRpcChann},
-                       conninfo = NConnInfo,
+                       conninfo = NConnInfo1,
                        clientinfo = ClientInfo,
                        conn_state = accepted,
                        timers = #{}
@@ -165,7 +172,8 @@ init(ConnInfo = #{socktype := Socktype,
                              #{socktype => socktype(Socktype),
                                peername => address(Peername),
                                sockname => address(Sockname)})},
-            try_dispatch(on_socket_created, wrap(Req), Channel)
+            start_idle_checking_timer(
+              try_dispatch(on_socket_created, wrap(Req), Channel))
     end.
 
 register_the_anonymous_client(ClientInfo, ConnInfo) ->
@@ -184,6 +192,12 @@ register_the_anonymous_client(ClientInfo, ConnInfo) ->
 unregister_the_anonymous_client(ClientId) ->
     emqx_cm:unregister_channel(ClientId).
 
+start_idle_checking_timer(Channel = #channel{conninfo = #{socktype := udp}}) ->
+    ensure_timer(idle_timer, Channel);
+
+start_idle_checking_timer(Channel) ->
+    Channel.
+
 %% @private
 peercert(NoSsl, ConnInfo) when NoSsl == nossl;
                                NoSsl == undefined ->
@@ -267,6 +281,9 @@ handle_timeout(_TRef, {keepalive, StatVal},
 handle_timeout(_TRef, force_close, Channel = #channel{closed_reason = Reason}) ->
     {shutdown, Reason, Channel};
 
+handle_timeout(_TRef, force_close_idle, Channel) ->
+    {shutdown, idle_timeout, Channel};
+
 handle_timeout(_TRef, Msg, Channel) ->
     ?WARN("Unexpected timeout: ~p", [Msg]),
     {ok, Channel}.
@@ -328,7 +345,8 @@ handle_call({start_timer, keepalive, Interval},
     NConnInfo = ConnInfo#{keepalive => Interval},
     NClientInfo = ClientInfo#{keepalive => Interval},
     NChannel = Channel#channel{conninfo = NConnInfo, clientinfo = NClientInfo},
-    {reply, ok, [{event, updated}], ensure_keepalive(NChannel)};
+    {reply, ok, [{event, updated}],
+     ensure_keepalive(cancel_timer(idle_timer, NChannel))};
 
 handle_call({subscribe, TopicFilter, Qos},
             Channel = #channel{
@@ -561,6 +579,12 @@ reset_timer(Name, Channel) ->
 clean_timer(Name, Channel = #channel{timers = Timers}) ->
     Channel#channel{timers = maps:remove(Name, Timers)}.
 
+cancel_timer(Name, Channel = #channel{timers = Timers}) ->
+    emqx_misc:cancel_timer(maps:get(Name, Timers, undefined)),
+    clean_timer(Name, Channel).
+
+interval(idle_timer, #channel{conninfo = #{idle_timeout := IdleTimeout}}) ->
+    IdleTimeout;
 interval(force_timer, _) ->
     15000;
 interval(alive_timer, #channel{keepalive = Keepalive}) ->