Replace gen_server2 with gen_server for we cannot trace the size of drain queue

src/emqx_bridge.erl

@@ -16,9 +16,7 @@
 
 -module(emqx_bridge).
 
--author("Feng Lee <feng@emqtt.io>").
+-behaviour(gen_server).
-
--behaviour(gen_server2).
 
 -include("emqx.hrl").
 
@@ -61,7 +59,7 @@
 -spec(start_link(any(), pos_integer(), atom(), binary(), [option()]) ->
     {ok, pid()} | ignore | {error, term()}).
 start_link(Pool, Id, Node, Topic, Options) ->
-    gen_server2:start_link(?MODULE, [Pool, Id, Node, Topic, Options], []).
+    gen_server:start_link(?MODULE, [Pool, Id, Node, Topic, Options], []).
 
 %%--------------------------------------------------------------------
 %% gen_server callbacks

src/emqx_client.erl

@@ -18,9 +18,7 @@
 
 -module(emqx_client).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
-
--author("Feng Lee <feng@emqtt.io>").
 
 -include("emqx.hrl").
 
@@ -48,8 +46,8 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          code_change/3, terminate/2]).
 
-%% gen_server2 Callbacks
+%% TODO: How to emit stats?
--export([prioritise_call/4, prioritise_info/3, handle_pre_hibernate/1]).
+-export([handle_pre_hibernate/1]).
 
 %% Client State
 %% Unused fields: connname, peerhost, peerport
@@ -69,19 +67,19 @@ start_link(Conn, Env) ->
     {ok, proc_lib:spawn_link(?MODULE, init, [[Conn, Env]])}.
 
 info(CPid) ->
-    gen_server2:call(CPid, info).
+    gen_server:call(CPid, info).
 
 stats(CPid) ->
-    gen_server2:call(CPid, stats).
+    gen_server:call(CPid, stats).
 
 kick(CPid) ->
-    gen_server2:call(CPid, kick).
+    gen_server:call(CPid, kick).
 
 set_rate_limit(Cpid, Rl) ->
-    gen_server2:call(Cpid, {set_rate_limit, Rl}).
+    gen_server:call(Cpid, {set_rate_limit, Rl}).
 
 get_rate_limit(Cpid) ->
-    gen_server2:call(Cpid, get_rate_limit).
+    gen_server:call(Cpid, get_rate_limit).
 
 subscribe(CPid, TopicTable) ->
     CPid ! {subscribe, TopicTable}.
@@ -90,10 +88,10 @@ unsubscribe(CPid, Topics) ->
     CPid ! {unsubscribe, Topics}.
 
 session(CPid) ->
-    gen_server2:call(CPid, session, infinity).
+    gen_server:call(CPid, session, infinity).
 
 clean_acl_cache(CPid, Topic) ->
-    gen_server2:call(CPid, {clean_acl_cache, Topic}).
+    gen_server:call(CPid, {clean_acl_cache, Topic}).
 
 %%--------------------------------------------------------------------
 %% gen_server Callbacks
@@ -130,8 +128,8 @@ do_init(Conn, Env, Peername) ->
                                      enable_stats   = EnableStats,
                                      idle_timeout   = IdleTimout,
                                      force_gc_count = ForceGcCount}),
-    gen_server2:enter_loop(?MODULE, [], State, self(), IdleTimout,
+    gen_server:enter_loop(?MODULE, [{hibernate_after, 10000}],
-                           {backoff, 2000, 2000, 20000}).
+                          State, self(), IdleTimout).
 
 send_fun(Conn, Peername) ->
     Self = self(),
@@ -148,12 +146,6 @@ send_fun(Conn, Peername) ->
         end
     end.
 
-prioritise_call(Msg, _From, _Len, _State) ->
-    case Msg of info -> 10; stats -> 10; state -> 10; _ -> 5 end.
-
-prioritise_info(Msg, _Len, _State) ->
-    case Msg of {redeliver, _} -> 5; _ -> 0 end.
-
 handle_pre_hibernate(State) ->
     {hibernate, emqx_gc:reset_conn_gc_count(#client_state.force_gc_count, emit_stats(State))}.
 
@@ -241,7 +233,7 @@ handle_info({shutdown, conflict, {ClientId, NewPid}}, State) ->
     shutdown(conflict, State);
 
 handle_info(activate_sock, State) ->
-    {noreply, run_socket(State#client_state{conn_state = running}), hibernate};
+    {noreply, run_socket(State#client_state{conn_state = running})};
 
 handle_info({inet_async, _Sock, _Ref, {ok, Data}}, State) ->
     Size = iolist_size(Data),
@@ -253,7 +245,7 @@ handle_info({inet_async, _Sock, _Ref, {error, Reason}}, State) ->
     shutdown(Reason, State);
 
 handle_info({inet_reply, _Sock, ok}, State) ->
-    {noreply, gc(State), hibernate}; %% Tune GC
+    {noreply, gc(State)}; %% Tune GC
 
 handle_info({inet_reply, _Sock, {error, Reason}}, State) ->
     shutdown(Reason, State);
@@ -268,7 +260,7 @@ handle_info({keepalive, start, Interval}, State = #client_state{connection = Con
              end,
     case emqx_keepalive:start(StatFun, Interval, {keepalive, check}) of
         {ok, KeepAlive} ->
-            {noreply, State#client_state{keepalive = KeepAlive}, hibernate};
+            {noreply, State#client_state{keepalive = KeepAlive}};
         {error, Error} ->
             ?LOG(warning, "Keepalive error - ~p", [Error], State),
             shutdown(Error, State)
@@ -277,7 +269,7 @@ handle_info({keepalive, start, Interval}, State = #client_state{connection = Con
 handle_info({keepalive, check}, State = #client_state{keepalive = KeepAlive}) ->
     case emqx_keepalive:check(KeepAlive) of
         {ok, KeepAlive1} ->
-            {noreply, State#client_state{keepalive = KeepAlive1}, hibernate};
+            {noreply, State#client_state{keepalive = KeepAlive1}};
         {error, timeout} ->
             ?LOG(debug, "Keepalive timeout", [], State),
             shutdown(keepalive_timeout, State);
@@ -314,7 +306,7 @@ code_change(_OldVsn, State, _Extra) ->
 
 %% Receive and Parse TCP Data
 received(<<>>, State) ->
-    {noreply, gc(State), hibernate};
+    {noreply, gc(State)};
 
 received(Bytes, State = #client_state{parser       = Parser,
                                       packet_size  = PacketSize,
@@ -368,7 +360,7 @@ run_socket(State = #client_state{connection = Conn}) ->
 
 with_proto(Fun, State = #client_state{proto_state = ProtoState}) ->
     {ok, ProtoState1} = Fun(ProtoState),
-    {noreply, State#client_state{proto_state = ProtoState1}, hibernate}.
+    {noreply, State#client_state{proto_state = ProtoState1}}.
 
 emit_stats(State = #client_state{proto_state = ProtoState}) ->
     emit_stats(emqx_protocol:clientid(ProtoState), State).

src/emqx_cm.erl

@@ -18,7 +18,7 @@
 
 -module(emqx_cm).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
 
 -author("Feng Lee <feng@emqtt.io>").
 
@@ -35,9 +35,6 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
-%% gen_server2 priorities
--export([prioritise_call/4, prioritise_cast/3, prioritise_info/3]).
-
 -record(state, {pool, id, statsfun, monitors}).
 
 -define(POOL, ?MODULE).
@@ -49,7 +46,7 @@
 %% @doc Start Client Manager
 -spec(start_link(atom(), pos_integer(), fun()) -> {ok, pid()} | ignore | {error, term()}).
 start_link(Pool, Id, StatsFun) ->
-    gen_server2:start_link(?MODULE, [Pool, Id, StatsFun], []).
+    gen_server:start_link(?MODULE, [Pool, Id, StatsFun], []).
 
 %% @doc Lookup Client by ClientId
 -spec(lookup(binary()) -> mqtt_client() | undefined).
@@ -67,12 +64,12 @@ lookup_proc(ClientId) when is_binary(ClientId) ->
 %% @doc Register ClientId with Pid.
 -spec(reg(mqtt_client()) -> ok).
 reg(Client = #mqtt_client{client_id = ClientId}) ->
-    gen_server2:call(pick(ClientId), {reg, Client}, 120000).
+    gen_server:call(pick(ClientId), {reg, Client}, 120000).
 
 %% @doc Unregister clientId with pid.
 -spec(unreg(binary()) -> ok).
 unreg(ClientId) when is_binary(ClientId) ->
-    gen_server2:cast(pick(ClientId), {unreg, ClientId, self()}).
+    gen_server:cast(pick(ClientId), {unreg, ClientId, self()}).
 
 pick(ClientId) -> gproc_pool:pick_worker(?POOL, ClientId).
 
@@ -84,15 +81,6 @@ init([Pool, Id, StatsFun]) ->
     ?GPROC_POOL(join, Pool, Id),
     {ok, #state{pool = Pool, id = Id, statsfun = StatsFun, monitors = dict:new()}}.
 
-prioritise_call(Req, _From, _Len, _State) ->
-    case Req of {reg, _Client} -> 2; _ -> 1 end.
-
-prioritise_cast(Msg, _Len, _State) ->
-    case Msg of {unreg, _ClientId, _Pid} -> 9; _ -> 1 end.
-
-prioritise_info(_Msg, _Len, _State) ->
-    3.
-
 handle_call({reg, Client = #mqtt_client{client_id  = ClientId,
                                         client_pid = Pid}}, _From, State) ->
     case lookup_proc(ClientId) of

src/emqx_pubsub.erl

@@ -16,9 +16,7 @@
 
 -module(emqx_pubsub).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
-
--author("Feng Lee <feng@emqtt.io>").
 
 -include("emqx.hrl").
 
@@ -48,7 +46,8 @@
 
 -spec(start_link(atom(), pos_integer(), list()) -> {ok, pid()} | ignore | {error, term()}).
 start_link(Pool, Id, Env) ->
-    gen_server2:start_link({local, ?PROC_NAME(?MODULE, Id)}, ?MODULE, [Pool, Id, Env], []).
+    gen_server:start_link({local, ?PROC_NAME(?MODULE, Id)},
+                          ?MODULE, [Pool, Id, Env], [{hibernate_after, 10000}]).
 
 %%--------------------------------------------------------------------
 %% PubSub API
@@ -152,10 +151,10 @@ async_unsubscribe(Topic, Subscriber, Options) ->
     cast(pick(Topic), {unsubscribe, Topic, Subscriber, Options}).
 
 call(PubSub, Req) when is_pid(PubSub) ->
-    gen_server2:call(PubSub, Req, infinity).
+    gen_server:call(PubSub, Req, infinity).
 
 cast(PubSub, Msg) when is_pid(PubSub) ->
-    gen_server2:cast(PubSub, Msg).
+    gen_server:cast(PubSub, Msg).
 
 pick(Topic) ->
     gproc_pool:pick_worker(pubsub, Topic).
@@ -166,8 +165,7 @@ pick(Topic) ->
 
 init([Pool, Id, Env]) ->
     ?GPROC_POOL(join, Pool, Id),
-    {ok, #state{pool = Pool, id = Id, env = Env},
+    {ok, #state{pool = Pool, id = Id, env = Env}, hibernate}.
-     hibernate, {backoff, 2000, 2000, 20000}}.
 
 handle_call({subscribe, Topic, Subscriber, Options}, _From, State) ->
     add_subscriber(Topic, Subscriber, Options),
@@ -247,8 +245,8 @@ setstats(State) ->
     State.
 
 reply(Reply, State) ->
-    {reply, Reply, State, hibernate}.
+    {reply, Reply, State}.
 
 noreply(State) ->
-    {noreply, State, hibernate}.
+    {noreply, State}.
 

src/emqx_server.erl

@@ -16,9 +16,7 @@
 
 -module(emqx_server).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
-
--author("Feng Lee <feng@emqtt.io>").
 
 -include("emqx.hrl").
 
@@ -51,7 +49,8 @@
 %% @doc Start the server
 -spec(start_link(atom(), pos_integer(), list()) -> {ok, pid()} | ignore | {error, term()}).
 start_link(Pool, Id, Env) ->
-    gen_server2:start_link({local, ?PROC_NAME(?MODULE, Id)}, ?MODULE, [Pool, Id, Env], []).
+    gen_server:start_link({local, ?PROC_NAME(?MODULE, Id)},
+                          ?MODULE, [Pool, Id, Env], [{hibernate_after, 10000}]).
 
 %%--------------------------------------------------------------------
 %% PubSub API
@@ -167,10 +166,10 @@ subscribed(Topic, {SubId, SubPid}) when is_binary(Topic), is_binary(SubId), is_p
     ets:member(mqtt_subproperty, {Topic, {SubId, SubPid}}).
 
 call(Server, Req) ->
-    gen_server2:call(Server, Req, infinity).
+    gen_server:call(Server, Req, infinity).
 
 cast(Server, Msg) when is_pid(Server) ->
-    gen_server2:cast(Server, Msg).
+    gen_server:cast(Server, Msg).
 
 pick(SubPid) when is_pid(SubPid) ->
     gproc_pool:pick_worker(server, SubPid);
@@ -190,7 +189,7 @@ init([Pool, Id, Env]) ->
     ?GPROC_POOL(join, Pool, Id),
     State = #state{pool = Pool, id = Id, env = Env,
                    subids = #{}, submon = emqx_pmon:new()},
-    {ok, State, hibernate, {backoff, 2000, 2000, 20000}}.
+    {ok, State, hibernate}.
 
 handle_call({subscribe, Topic, Subscriber, Options}, _From, State) ->
     case do_subscribe(Topic, Subscriber, Options, State) of
@@ -321,8 +320,8 @@ setstats(State) ->
                         ets:info(mqtt_subscription, size)), State.
 
 reply(Reply, State) ->
-    {reply, Reply, State, hibernate}.
+    {reply, Reply, State}.
 
 noreply(State) ->
-    {noreply, State, hibernate}.
+    {noreply, State}.
 

src/emqx_session.erl

@@ -45,7 +45,7 @@
 
 -module(emqx_session).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
 
 -author("Feng Lee <feng@emqtt.io>").
 
@@ -73,9 +73,8 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
-%% gen_server2 Message Priorities
+%% TODO: gen_server Message Priorities
--export([prioritise_call/4, prioritise_cast/3, prioritise_info/3,
+-export([handle_pre_hibernate/1]).
-         handle_pre_hibernate/1]).
 
 -define(MQueue, emqx_mqueue).
 
@@ -175,7 +174,8 @@
 %% @doc Start a Session
 -spec(start_link(boolean(), {mqtt_client_id(), mqtt_username()}, pid()) -> {ok, pid()} | {error, term()}).
 start_link(CleanSess, {ClientId, Username}, ClientPid) ->
-    gen_server2:start_link(?MODULE, [CleanSess, {ClientId, Username}, ClientPid], []).
+    gen_server:start_link(?MODULE, [CleanSess, {ClientId, Username}, ClientPid],
+                          [{hibernate_after, 10000}]).
 
 %%--------------------------------------------------------------------
 %% PubSub API
@@ -184,13 +184,13 @@ start_link(CleanSess, {ClientId, Username}, ClientPid) ->
 %% @doc Subscribe topics
 -spec(subscribe(pid(), [{binary(), [emqx_topic:option()]}]) -> ok).
 subscribe(Session, TopicTable) -> %%TODO: the ack function??...
-    gen_server2:cast(Session, {subscribe, self(), TopicTable, fun(_) -> ok end}).
+    gen_server:cast(Session, {subscribe, self(), TopicTable, fun(_) -> ok end}).
 
 -spec(subscribe(pid(), mqtt_packet_id(), [{binary(), [emqx_topic:option()]}]) -> ok).
 subscribe(Session, PacketId, TopicTable) -> %%TODO: the ack function??...
     From = self(),
     AckFun = fun(GrantedQos) -> From ! {suback, PacketId, GrantedQos} end,
-    gen_server2:cast(Session, {subscribe, From, TopicTable, AckFun}).
+    gen_server:cast(Session, {subscribe, From, TopicTable, AckFun}).
 
 %% @doc Publish Message
 -spec(publish(pid(), mqtt_message()) -> ok | {error, term()}).
@@ -204,50 +204,50 @@ publish(_Session, Msg = #mqtt_message{qos = ?QOS_1}) ->
 
 publish(Session, Msg = #mqtt_message{qos = ?QOS_2}) ->
     %% Publish QoS2 to Session
-    gen_server2:call(Session, {publish, Msg}, ?TIMEOUT).
+    gen_server:call(Session, {publish, Msg}, ?TIMEOUT).
 
 %% @doc PubAck Message
 -spec(puback(pid(), mqtt_packet_id()) -> ok).
 puback(Session, PacketId) ->
-    gen_server2:cast(Session, {puback, PacketId}).
+    gen_server:cast(Session, {puback, PacketId}).
 
 -spec(pubrec(pid(), mqtt_packet_id()) -> ok).
 pubrec(Session, PacketId) ->
-    gen_server2:cast(Session, {pubrec, PacketId}).
+    gen_server:cast(Session, {pubrec, PacketId}).
 
 -spec(pubrel(pid(), mqtt_packet_id()) -> ok).
 pubrel(Session, PacketId) ->
-    gen_server2:cast(Session, {pubrel, PacketId}).
+    gen_server:cast(Session, {pubrel, PacketId}).
 
 -spec(pubcomp(pid(), mqtt_packet_id()) -> ok).
 pubcomp(Session, PacketId) ->
-    gen_server2:cast(Session, {pubcomp, PacketId}).
+    gen_server:cast(Session, {pubcomp, PacketId}).
 
 %% @doc Unsubscribe the topics
 -spec(unsubscribe(pid(), [{binary(), [emqx_topic:option()]}]) -> ok).
 unsubscribe(Session, TopicTable) ->
-    gen_server2:cast(Session, {unsubscribe, self(), TopicTable}).
+    gen_server:cast(Session, {unsubscribe, self(), TopicTable}).
 
 %% @doc Resume the session
 -spec(resume(pid(), mqtt_client_id(), pid()) -> ok).
 resume(Session, ClientId, ClientPid) ->
-    gen_server2:cast(Session, {resume, ClientId, ClientPid}).
+    gen_server:cast(Session, {resume, ClientId, ClientPid}).
 
 %% @doc Get session state
 state(Session) when is_pid(Session) ->
-    gen_server2:call(Session, state).
+    gen_server:call(Session, state).
 
 %% @doc Get session info
 -spec(info(pid() | #state{}) -> list(tuple())).
 info(Session) when is_pid(Session) ->
-    gen_server2:call(Session, info);
+    gen_server:call(Session, info);
 
 info(State) when is_record(State, state) ->
     ?record_to_proplist(state, State, ?INFO_KEYS).
 
 -spec(stats(pid() | #state{}) -> list({atom(), non_neg_integer()})).
 stats(Session) when is_pid(Session) ->
-    gen_server2:call(Session, stats);
+    gen_server:call(Session, stats);
 
 stats(#state{max_subscriptions = MaxSubscriptions,
              subscriptions     = Subscriptions,
@@ -272,7 +272,7 @@ stats(#state{max_subscriptions = MaxSubscriptions,
 %% @doc Destroy the session
 -spec(destroy(pid(), mqtt_client_id()) -> ok).
 destroy(Session, ClientId) ->
-    gen_server2:cast(Session, {destroy, ClientId}).
+    gen_server:cast(Session, {destroy, ClientId}).
 
 %%--------------------------------------------------------------------
 %% gen_server Callbacks
@@ -311,7 +311,7 @@ init([CleanSess, {ClientId, Username}, ClientPid]) ->
                    created_at        = os:timestamp()},
     emqx_sm:register_session(ClientId, CleanSess, info(State)),
     emqx_hooks:run('session.created', [ClientId, Username]),
-    {ok, emit_stats(State), hibernate, {backoff, 1000, 1000, 10000}}.
+    {ok, emit_stats(State), hibernate}.
 
 init_stats(Keys) ->
     lists:foreach(fun(K) -> put(K, 0) end, Keys).
@@ -319,30 +319,6 @@ init_stats(Keys) ->
 binding(ClientPid) ->
     case node(ClientPid) =:= node() of true -> local; false -> remote end.
 
-prioritise_call(Msg, _From, _Len, _State) ->
-    case Msg of info -> 10; stats -> 10; state -> 10; _ -> 5 end.
-
-prioritise_cast(Msg, _Len, _State) ->
-    case Msg of
-        {destroy, _}        -> 10;
-        {resume, _, _}      -> 9;
-        {pubrel,  _}        -> 8;
-        {pubcomp, _}        -> 8;
-        {pubrec,  _}        -> 8;
-        {puback,  _}        -> 7;
-        {unsubscribe, _, _} -> 6;
-        {subscribe, _, _}   -> 5;
-        _                   -> 0
-    end.
-
-prioritise_info(Msg, _Len, _State) ->
-    case Msg of
-        {'EXIT', _, _}   -> 10;
-        {timeout, _, _}  -> 5;
-        {dispatch, _, _} -> 1;
-        _                -> 0
-    end.
-
 handle_pre_hibernate(State) ->
     {hibernate, emqx_gc:reset_conn_gc_count(#state.force_gc_count, emit_stats(State))}.
 
@@ -406,7 +382,7 @@ handle_cast({subscribe, From, TopicTable, AckFun},
                 {[NewQos|QosAcc], SubMap1}
         end, {[], Subscriptions}, TopicTable),
     AckFun(lists:reverse(GrantedQos)),
-    hibernate(emit_stats(State#state{subscriptions = Subscriptions1}));
+    {noreply, emit_stats(State#state{subscriptions = Subscriptions1}), hibernate};
 
 handle_cast({unsubscribe, From, TopicTable},
             State = #state{client_id     = ClientId,
@@ -428,7 +404,7 @@ handle_cast({unsubscribe, From, TopicTable},
                         SubMap
                 end
         end, Subscriptions, TopicTable),
-    hibernate(emit_stats(State#state{subscriptions = Subscriptions1}));
+    {noreply, emit_stats(State#state{subscriptions = Subscriptions1}), hibernate};
 
 %% PUBACK:
 handle_cast({puback, PacketId}, State = #state{inflight = Inflight}) ->
@@ -525,7 +501,7 @@ handle_cast({resume, ClientId, ClientPid},
     end,
 
     %% Replay delivery and Dequeue pending messages
-    hibernate(emit_stats(dequeue(retry_delivery(true, State1))));
+    {noreply, emit_stats(dequeue(retry_delivery(true, State1)))};
 
 handle_cast({destroy, ClientId},
             State = #state{client_id = ClientId, client_pid = undefined}) ->
@@ -543,21 +519,21 @@ handle_cast(Msg, State) ->
 %% Ignore Messages delivered by self
 handle_info({dispatch, _Topic, #mqtt_message{from = {ClientId, _}}},
              State = #state{client_id = ClientId, ignore_loop_deliver = true}) ->
-    hibernate(State);
+    {noreply, State};
 
 %% Dispatch Message
 handle_info({dispatch, Topic, Msg}, State) when is_record(Msg, mqtt_message) ->
-    hibernate(gc(dispatch(tune_qos(Topic, reset_dup(Msg), State), State)));
+    {noreply, gc(dispatch(tune_qos(Topic, reset_dup(Msg), State), State))};
 
 %% Do nothing if the client has been disconnected.
 handle_info({timeout, _Timer, retry_delivery}, State = #state{client_pid = undefined}) ->
-    hibernate(emit_stats(State#state{retry_timer = undefined}));
+    {noreply, emit_stats(State#state{retry_timer = undefined})};
 
 handle_info({timeout, _Timer, retry_delivery}, State) ->
-    hibernate(emit_stats(retry_delivery(false, State#state{retry_timer = undefined})));
+    {noreply, emit_stats(retry_delivery(false, State#state{retry_timer = undefined}))};
 
 handle_info({timeout, _Timer, check_awaiting_rel}, State) ->
-    hibernate(expire_awaiting_rel(emit_stats(State#state{await_rel_timer = undefined})));
+    {noreply, expire_awaiting_rel(emit_stats(State#state{await_rel_timer = undefined}))};
 
 handle_info({timeout, _Timer, expired}, State) ->
     ?LOG(info, "Expired, shutdown now.", [], State),
@@ -574,17 +550,17 @@ handle_info({'EXIT', ClientPid, Reason},
     ?LOG(info, "Client ~p EXIT for ~p", [ClientPid, Reason], State),
     ExpireTimer = start_timer(Interval, expired),
     State1 = State#state{client_pid = undefined, expiry_timer = ExpireTimer},
-    hibernate(emit_stats(State1));
+    {noreply, emit_stats(State1), hibernate};
 
 handle_info({'EXIT', Pid, _Reason}, State = #state{old_client_pid = Pid}) ->
     %%ignore
-    hibernate(State);
+    {noreply, State, hibernate};
 
 handle_info({'EXIT', Pid, Reason}, State = #state{client_pid = ClientPid}) ->
 
     ?LOG(error, "Unexpected EXIT: client_pid=~p, exit_pid=~p, reason=~p",
          [ClientPid, Pid, Reason], State),
-    hibernate(State);
+    {noreply, State, hibernate};
 
 handle_info(Info, Session) ->
     ?UNEXPECTED_INFO(Info, Session).
@@ -857,9 +833,6 @@ inc_stats(Key) -> put(Key, get(Key) + 1).
 reply(Reply, State) ->
     {reply, Reply, State, hibernate}.
 
-hibernate(State) ->
-    {noreply, State, hibernate}.
-
 shutdown(Reason, State) ->
     {stop, {shutdown, Reason}, State}.
 

src/emqx_sm.erl

@@ -16,9 +16,7 @@
 
 -module(emqx_sm).
 
--author("Feng Lee <feng@emqtt.io>").
+-behaviour(gen_server).
-
--behaviour(gen_server2).
 
 -include("emqx.hrl").
 
@@ -44,9 +42,6 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
-%% gen_server2 priorities
--export([prioritise_call/4, prioritise_cast/3, prioritise_info/3]).
-
 -record(state, {pool, id, monitors}).
 
 -define(POOL, ?MODULE).
@@ -78,7 +73,7 @@ mnesia(copy) ->
 %% @doc Start a session manager
 -spec(start_link(atom(), pos_integer()) -> {ok, pid()} | ignore | {error, term()}).
 start_link(Pool, Id) ->
-    gen_server2:start_link({local, ?PROC_NAME(?MODULE, Id)}, ?MODULE, [Pool, Id], []).
+    gen_server:start_link({local, ?PROC_NAME(?MODULE, Id)}, ?MODULE, [Pool, Id], []).
 
 %% @doc Start a session
 -spec(start_session(boolean(), {binary(), binary() | undefined}) -> {ok, pid(), boolean()} | {error, term()}).
@@ -123,7 +118,7 @@ dispatch(ClientId, Topic, Msg) ->
     end.
 
 call(SM, Req) ->
-    gen_server2:call(SM, Req, ?TIMEOUT). %%infinity).
+    gen_server:call(SM, Req, ?TIMEOUT). %%infinity).
 
 %% @doc for debug.
 local_sessions() ->
@@ -137,15 +132,6 @@ init([Pool, Id]) ->
     ?GPROC_POOL(join, Pool, Id),
     {ok, #state{pool = Pool, id = Id, monitors = dict:new()}}.
 
-prioritise_call(_Msg, _From, _Len, _State) ->
-    1.
-
-prioritise_cast(_Msg, _Len, _State) ->
-    0.
-
-prioritise_info(_Msg, _Len, _State) ->
-    2.
-
 %% Persistent Session
 handle_call({start_session, false, {ClientId, Username}, ClientPid}, _From, State) ->
     case lookup_session(ClientId) of

src/emqx_ws_client.erl

@@ -18,7 +18,7 @@
 
 -module(emqx_ws_client).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
 
 -author("Feng Lee <feng@emqtt.io>").
 
@@ -46,8 +46,8 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
-%% gen_server2 Callbacks
+%% TODO: remove ...
--export([prioritise_call/4, prioritise_info/3, handle_pre_hibernate/1]).
+-export([handle_pre_hibernate/1]).
 
 %% WebSocket Client State
 -record(wsclient_state, {ws_pid, peername, connection, proto_state, keepalive,
@@ -61,17 +61,17 @@
 
 %% @doc Start WebSocket Client.
 start_link(Env, WsPid, Req, ReplyChannel) ->
-    gen_server2:start_link(?MODULE, [Env, WsPid, Req, ReplyChannel],
+    gen_server:start_link(?MODULE, [Env, WsPid, Req, ReplyChannel],
-                           [{spawn_opt, ?FULLSWEEP_OPTS}]). %% Tune GC.
+                          [[{hibernate_after, 10000}]]).
 
 info(CPid) ->
-    gen_server2:call(CPid, info).
+    gen_server:call(CPid, info).
 
 stats(CPid) ->
-    gen_server2:call(CPid, stats).
+    gen_server:call(CPid, stats).
 
 kick(CPid) ->
-    gen_server2:call(CPid, kick).
+    gen_server:call(CPid, kick).
 
 subscribe(CPid, TopicTable) ->
     CPid ! {subscribe, TopicTable}.
@@ -80,10 +80,10 @@ unsubscribe(CPid, Topics) ->
     CPid ! {unsubscribe, Topics}.
 
 session(CPid) ->
-    gen_server2:call(CPid, session).
+    gen_server:call(CPid, session).
 
 clean_acl_cache(CPid, Topic) ->
-    gen_server2:call(CPid, {clean_acl_cache, Topic}).
+    gen_server:call(CPid, {clean_acl_cache, Topic}).
 
 %%--------------------------------------------------------------------
 %% gen_server Callbacks
@@ -116,12 +116,6 @@ init([Env, WsPid, Req, ReplyChannel]) ->
                              exit({shutdown, Reason})
     end.
 
-prioritise_call(Msg, _From, _Len, _State) ->
-    case Msg of info -> 10; stats -> 10; state -> 10; _ -> 5 end.
-
-prioritise_info(Msg, _Len, _State) ->
-    case Msg of {redeliver, _} -> 5; _ -> 0 end.
-
 handle_pre_hibernate(State = #wsclient_state{ws_pid = WsPid}) ->
     erlang:garbage_collect(WsPid),
     {hibernate, emqx_gc:reset_conn_gc_count(#wsclient_state.force_gc_count, emit_stats(State))}.

src/priority_queue.erl

@@ -1,259 +0,0 @@
-%% The contents of this file are subject to the Mozilla Public License
-%% Version 1.1 (the "License"); you may not use this file except in
-%% compliance with the License. You may obtain a copy of the License
-%% at http://www.mozilla.org/MPL/
-%%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and
-%% limitations under the License.
-%%
-%% The Original Code is RabbitMQ.
-%%
-%% The Initial Developer of the Original Code is GoPivotal, Inc.
-%% Copyright (c) 2007-2015 Pivotal Software, Inc.  All rights reserved.
-%%
-
-%% Priority queues have essentially the same interface as ordinary
-%% queues, except that a) there is an in/3 that takes a priority, and
-%% b) we have only implemented the core API we need.
-%%
-%% Priorities should be integers - the higher the value the higher the
-%% priority - but we don't actually check that.
-%%
-%% in/2 inserts items with priority 0.
-%%
-%% We optimise the case where a priority queue is being used just like
-%% an ordinary queue. When that is the case we represent the priority
-%% queue as an ordinary queue. We could just call into the 'queue'
-%% module for that, but for efficiency we implement the relevant
-%% functions directly in here, thus saving on inter-module calls and
-%% eliminating a level of boxing.
-%%
-%% When the queue contains items with non-zero priorities, it is
-%% represented as a sorted kv list with the inverted Priority as the
-%% key and an ordinary queue as the value. Here again we use our own
-%% ordinary queue implemention for efficiency, often making recursive
-%% calls into the same function knowing that ordinary queues represent
-%% a base case.
-
--module(priority_queue).
-
--export([new/0, is_queue/1, is_empty/1, len/1, plen/2, to_list/1, from_list/1,
-         in/2, in/3, out/1, out/2, out_p/1, join/2, filter/2, fold/3, highest/1]).
-
-%%----------------------------------------------------------------------------
-
--ifdef(use_specs).
-
--type(q() :: pqueue()).
--type(priority() :: integer() | 'infinity').
--type(squeue() :: {queue, [any()], [any()], non_neg_integer()}).
--type(pqueue() ::  squeue() | {pqueue, [{priority(), squeue()}]}).
-
--export_type([q/0]).
-
--spec(new/0 :: () -> pqueue()).
--spec(is_queue/1 :: (any()) -> boolean()).
--spec(is_empty/1 :: (pqueue()) -> boolean()).
--spec(len/1 :: (pqueue()) -> non_neg_integer()).
--spec(plen/2 :: (priority(), pqueue()) -> non_neg_integer()).
--spec(to_list/1 :: (pqueue()) -> [{priority(), any()}]).
--spec(from_list/1 :: ([{priority(), any()}]) -> pqueue()).
--spec(in/2 :: (any(), pqueue()) -> pqueue()).
--spec(in/3 :: (any(), priority(), pqueue()) -> pqueue()).
--spec(out/1 :: (pqueue()) -> {empty | {value, any()}, pqueue()}).
--spec(out_p/1 :: (pqueue()) -> {empty | {value, any(), priority()}, pqueue()}).
--spec(join/2 :: (pqueue(), pqueue()) -> pqueue()).
--spec(filter/2 :: (fun ((any()) -> boolean()), pqueue()) -> pqueue()).
--spec(fold/3 ::
-        (fun ((any(), priority(), A) -> A), A, pqueue()) -> A).
--spec(highest/1 :: (pqueue()) -> priority() | 'empty').
-
--endif.
-
-%%----------------------------------------------------------------------------
-
-new() ->
-    {queue, [], [], 0}.
-
-is_queue({queue, R, F, L}) when is_list(R), is_list(F), is_integer(L) ->
-    true;
-is_queue({pqueue, Queues}) when is_list(Queues) ->
-    lists:all(fun ({infinity, Q}) -> is_queue(Q);
-                  ({P,        Q}) -> is_integer(P) andalso is_queue(Q)
-              end, Queues);
-is_queue(_) ->
-    false.
-
-is_empty({queue, [], [], 0}) ->
-    true;
-is_empty(_) ->
-    false.
-
-len({queue, _R, _F, L}) ->
-    L;
-len({pqueue, Queues}) ->
-    lists:sum([len(Q) || {_, Q} <- Queues]).
-
-plen(0, {queue, _R, _F, L}) ->
-    L;
-plen(_, {queue, _R, _F, _}) ->
-    0;
-plen(P, {pqueue, Queues}) ->
-    case lists:keysearch(maybe_negate_priority(P), 1, Queues) of
-        {value, {_, Q}} -> len(Q);
-        false           -> 0
-    end.
-
-to_list({queue, In, Out, _Len}) when is_list(In), is_list(Out) ->
-    [{0, V} || V <- Out ++ lists:reverse(In, [])];
-to_list({pqueue, Queues}) ->
-    [{maybe_negate_priority(P), V} || {P, Q} <- Queues,
-                                      {0, V} <- to_list(Q)].
-
-from_list(L) ->
-    lists:foldl(fun ({P, E}, Q) -> in(E, P, Q) end, new(), L).
-
-in(Item, Q) ->
-    in(Item, 0, Q).
-
-in(X, 0, {queue, [_] = In, [], 1}) ->
-    {queue, [X], In, 2};
-in(X, 0, {queue, In, Out, Len}) when is_list(In), is_list(Out) ->
-    {queue, [X|In], Out, Len + 1};
-in(X, Priority, _Q = {queue, [], [], 0}) ->
-    in(X, Priority, {pqueue, []});
-in(X, Priority, Q = {queue, _, _, _}) ->
-    in(X, Priority, {pqueue, [{0, Q}]});
-in(X, Priority, {pqueue, Queues}) ->
-    P = maybe_negate_priority(Priority),
-    {pqueue, case lists:keysearch(P, 1, Queues) of
-                 {value, {_, Q}} ->
-                     lists:keyreplace(P, 1, Queues, {P, in(X, Q)});
-                 false when P == infinity ->
-                     [{P, {queue, [X], [], 1}} | Queues];
-                 false ->
-                     case Queues of
-                         [{infinity, InfQueue} | Queues1] ->
-                             [{infinity, InfQueue} |
-                              lists:keysort(1, [{P, {queue, [X], [], 1}} | Queues1])];
-                         _ ->
-                             lists:keysort(1, [{P, {queue, [X], [], 1}} | Queues])
-                     end
-             end}.
-
-out({queue, [], [], 0} = Q) ->
-    {empty, Q};
-out({queue, [V], [], 1}) ->
-    {{value, V}, {queue, [], [], 0}};
-out({queue, [Y|In], [], Len}) ->
-    [V|Out] = lists:reverse(In, []),
-    {{value, V}, {queue, [Y], Out, Len - 1}};
-out({queue, In, [V], Len}) when is_list(In) ->
-    {{value,V}, r2f(In, Len - 1)};
-out({queue, In,[V|Out], Len}) when is_list(In) ->
-    {{value, V}, {queue, In, Out, Len - 1}};
-out({pqueue, [{P, Q} | Queues]}) ->
-    {R, Q1} = out(Q),
-    NewQ = case is_empty(Q1) of
-               true -> case Queues of
-                           []           -> {queue, [], [], 0};
-                           [{0, OnlyQ}] -> OnlyQ;
-                           [_|_]        -> {pqueue, Queues}
-                       end;
-               false -> {pqueue, [{P, Q1} | Queues]}
-           end,
-    {R, NewQ}.
-
-out_p({queue, _, _, _}       = Q) -> add_p(out(Q), 0);
-out_p({pqueue, [{P, _} | _]} = Q) -> add_p(out(Q), maybe_negate_priority(P)).
-
-out(0, {queue, _, _, _} = Q) ->
-    out(Q);
-out(Priority, {queue, _, _, _}) ->
-    erlang:error(badarg, [Priority]);
-out(Priority, {pqueue, Queues}) ->
-    P = maybe_negate_priority(Priority),
-    case lists:keysearch(P, 1, Queues) of
-        {value, {_, Q}} ->
-            {R, Q1} = out(Q),
-            Queues1 = case is_empty(Q1) of
-                true  -> lists:keydelete(P, 1, Queues);
-                false -> lists:keyreplace(P, 1, Queues, {P, Q1})
-            end,
-            {R, case Queues1 of
-                    []           -> {queue, [], [], 0};
-                    [{0, OnlyQ}] -> OnlyQ;
-                    [_|_]        -> {pqueue, Queues1}
-                end};
-        false ->
-            {empty, {pqueue, Queues}}
-    end.
-
-add_p(R, P) -> case R of
-                   {empty, Q}      -> {empty, Q};
-                   {{value, V}, Q} -> {{value, V, P}, Q}
-               end.
-
-join(A, {queue, [], [], 0}) ->
-    A;
-join({queue, [], [], 0}, B) ->
-    B;
-join({queue, AIn, AOut, ALen}, {queue, BIn, BOut, BLen}) ->
-    {queue, BIn, AOut ++ lists:reverse(AIn, BOut), ALen + BLen};
-join(A = {queue, _, _, _}, {pqueue, BPQ}) ->
-    {Pre, Post} =
-        lists:splitwith(fun ({P, _}) -> P < 0 orelse P == infinity end, BPQ),
-    Post1 = case Post of
-                []                        -> [ {0, A} ];
-                [ {0, ZeroQueue} | Rest ] -> [ {0, join(A, ZeroQueue)} | Rest ];
-                _                         -> [ {0, A} | Post ]
-            end,
-    {pqueue, Pre ++ Post1};
-join({pqueue, APQ}, B = {queue, _, _, _}) ->
-    {Pre, Post} =
-        lists:splitwith(fun ({P, _}) -> P < 0 orelse P == infinity end, APQ),
-    Post1 = case Post of
-                []                        -> [ {0, B} ];
-                [ {0, ZeroQueue} | Rest ] -> [ {0, join(ZeroQueue, B)} | Rest ];
-                _                         -> [ {0, B} | Post ]
-            end,
-    {pqueue, Pre ++ Post1};
-join({pqueue, APQ}, {pqueue, BPQ}) ->
-    {pqueue, merge(APQ, BPQ, [])}.
-
-merge([], BPQ, Acc) ->
-    lists:reverse(Acc, BPQ);
-merge(APQ, [], Acc) ->
-    lists:reverse(Acc, APQ);
-merge([{P, A}|As], [{P, B}|Bs], Acc) ->
-    merge(As, Bs, [ {P, join(A, B)} | Acc ]);
-merge([{PA, A}|As], Bs = [{PB, _}|_], Acc) when PA < PB orelse PA == infinity ->
-    merge(As, Bs, [ {PA, A} | Acc ]);
-merge(As = [{_, _}|_], [{PB, B}|Bs], Acc) ->
-    merge(As, Bs, [ {PB, B} | Acc ]).
-
-filter(Pred, Q) -> fold(fun(V, P, Acc) ->
-                                case Pred(V) of
-                                    true  -> in(V, P, Acc);
-                                    false -> Acc
-                                end
-                        end, new(), Q).
-
-fold(Fun, Init, Q) -> case out_p(Q) of
-                          {empty, _Q}         -> Init;
-                          {{value, V, P}, Q1} -> fold(Fun, Fun(V, P, Init), Q1)
-                      end.
-
-highest({queue, [], [], 0})     -> empty;
-highest({queue, _, _, _})       -> 0;
-highest({pqueue, [{P, _} | _]}) -> maybe_negate_priority(P).
-
-r2f([],      0) -> {queue, [], [], 0};
-r2f([_] = R, 1) -> {queue, [], R, 1};
-r2f([X,Y],   2) -> {queue, [X], [Y], 2};
-r2f([X,Y|R], L) -> {queue, [X,Y], lists:reverse(R, []), L}.
-
-maybe_negate_priority(infinity) -> infinity;
-maybe_negate_priority(P)        -> -P.