From 7f22265e31b208c4f7124a13b1e5f4786c708b0c Mon Sep 17 00:00:00 2001
From: Feng Lee <feng@emqtt.io>
Date: Thu, 20 Jul 2017 14:22:18 +0800
Subject: [PATCH] Use global:trans/2 to clean routes and sessions

---
 src/emqttd_router.erl    | 11 ++++++++---
 src/emqttd_sm_helper.erl |  6 ++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/emqttd_router.erl b/src/emqttd_router.erl
index 8806e9904..b3dd8b4ad 100644
--- a/src/emqttd_router.erl
+++ b/src/emqttd_router.erl
@@ -48,6 +48,8 @@
 
 -define(ROUTER, ?MODULE).
 
+-define(LOCK, {?ROUTER, clean_routes}).
+
 %%--------------------------------------------------------------------
 %% Mnesia Bootstrap
 %%--------------------------------------------------------------------
@@ -231,7 +233,7 @@ handle_cast({add_local_route, Topic}, State) ->
     %% why node()...?
     ets:insert(mqtt_local_route, {Topic, node()}),
     {noreply, State};
-    
+
 handle_cast({del_local_route, Topic}, State) ->
     ets:delete(mqtt_local_route, Topic),
     {noreply, State};
@@ -240,8 +242,11 @@ handle_cast(_Msg, State) ->
     {noreply, State}.
 
 handle_info({membership, {mnesia, down, Node}}, State) ->
-    clean_routes_(Node),
-    update_stats_(),
+    global:trans({?LOCK, self()},
+                 fun() ->
+                     clean_routes_(Node),
+                     update_stats_()
+                 end),
     {noreply, State, hibernate};
 
 handle_info({membership, _Event}, State) ->
diff --git a/src/emqttd_sm_helper.erl b/src/emqttd_sm_helper.erl
index 2081ea9e5..2e8e9a749 100644
--- a/src/emqttd_sm_helper.erl
+++ b/src/emqttd_sm_helper.erl
@@ -36,6 +36,8 @@
 
 -record(state, {stats_fun, ticker}).
 
+-define(LOCK, {?MODULE, clean_sessions}).
+
 %% @doc Start a session helper
 -spec(start_link(fun()) -> {ok, pid()} | ignore | {error, any()}).
 start_link(StatsFun) ->
@@ -59,8 +61,8 @@ handle_info({membership, {mnesia, down, Node}}, State) ->
                                          [{'==', {node, '$2'}, Node}], ['$1']}]),
             lists:foreach(fun(ClientId) -> mnesia:delete({mqtt_session, ClientId}) end, ClientIds)
           end,
-    mnesia:async_dirty(Fun),
-    {noreply, State};
+    global:trans({?LOCK, self()}, fun() -> mnesia:async_dirty(Fun) end),
+    {noreply, State, hibernate};
 
 handle_info({membership, _Event}, State) ->
     {noreply, State};