From 64724573427faaf4a2c7e406513f2100d0975d43 Mon Sep 17 00:00:00 2001
From: Frank Feng <sandriver@163.com>
Date: Sun, 12 Mar 2017 23:06:57 +0800
Subject: [PATCH] Match {error,einval}

---
 src/emqttd_client.erl    |  9 +++++++--
 src/emqttd_keepalive.erl | 25 ++++++++++++++-----------
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/src/emqttd_client.erl b/src/emqttd_client.erl
index e3e68b8e4..a6ddd9eb2 100644
--- a/src/emqttd_client.erl
+++ b/src/emqttd_client.erl
@@ -252,8 +252,13 @@ handle_info({keepalive, start, Interval}, State = #client_state{connection = Con
                     {error, Error}              -> {error, Error}
                 end
              end,
-    KeepAlive = emqttd_keepalive:start(StatFun, Interval, {keepalive, check}),
-    {noreply, State#client_state{keepalive = KeepAlive}, hibernate};
+    case emqttd_keepalive:start(StatFun, Interval, {keepalive, check}) of
+        {ok, KeepAlive} ->
+            {noreply, State#client_state{keepalive = KeepAlive}, hibernate};
+        {error, Error} ->
+            ?LOG(warning, "Keepalive error - ~p", [Error], State),
+            shutdown(Error, State)
+    end;
 
 handle_info({keepalive, check}, State = #client_state{keepalive = KeepAlive}) ->
     case emqttd_keepalive:check(KeepAlive) of
diff --git a/src/emqttd_keepalive.erl b/src/emqttd_keepalive.erl
index 51d45c89c..ae8f6ffbe 100644
--- a/src/emqttd_keepalive.erl
+++ b/src/emqttd_keepalive.erl
@@ -29,14 +29,18 @@
 -export_type([keepalive/0]).
 
 %% @doc Start a keepalive
--spec(start(fun(), integer(), any()) -> undefined | keepalive()).
+-spec(start(fun(), integer(), any()) -> {ok, keepalive()} | {error, any()}).
 start(_, 0, _) ->
-    undefined;
+    {ok, #keepalive{}};
 start(StatFun, TimeoutSec, TimeoutMsg) ->
-    {ok, StatVal} = StatFun(),
-    #keepalive{statfun = StatFun, statval = StatVal,
-               tsec = TimeoutSec, tmsg = TimeoutMsg,
-               tref = timer(TimeoutSec, TimeoutMsg)}.
+    case StatFun() of
+        {ok, StatVal} ->
+            {ok, #keepalive{statfun = StatFun, statval = StatVal,
+                       tsec = TimeoutSec, tmsg = TimeoutMsg,
+                       tref = timer(TimeoutSec, TimeoutMsg)}};
+        {error, Error} ->
+            {error, Error}
+    end.
 
 %% @doc Check keepalive, called when timeout.
 -spec(check(keepalive()) -> {ok, keepalive()} | {error, any()}).
@@ -59,12 +63,11 @@ resume(KeepAlive = #keepalive{tsec = TimeoutSec, tmsg = TimeoutMsg}) ->
 
 %% @doc Cancel Keepalive
 -spec(cancel(keepalive()) -> ok).
-cancel(#keepalive{tref = TRef}) ->
-    cancel(TRef);
-cancel(undefined) -> 
+cancel(#keepalive{tref = TRef}) when is_reference(TRef) ->
+    erlang:cancel_timer(TRef),
     ok;
-cancel(TRef) ->
-    catch erlang:cancel_timer(TRef).
+cancel(_) ->
+    ok.
 
 timer(Sec, Msg) ->
     erlang:send_after(timer:seconds(Sec), self(), Msg).