[#129] monitor gun connection

rebar.config

@@ -30,7 +30,8 @@
   {test, [
     {deps, [
       {katana_test, "0.1.1"},
-      {mixer, "0.1.5", {pkg, inaka_mixer}}
+      {mixer, "0.1.5", {pkg, inaka_mixer}},
+      {meck, "0.8.4"}
     ]}
   ]}
 ]}.

src/apns_connection.erl

@@ -29,6 +29,7 @@
         , port/1
         , certfile/1
         , keyfile/1
+        , gun_connection/1
         ]).
 
 %% gen_server callbacks
@@ -59,6 +60,7 @@
 
 -type state()        :: #{ connection     := connection()
                          , gun_connection := pid()
+                         , gun_monitor    := reference()
                          }.
 
 %%%===================================================================
@@ -87,27 +89,30 @@ default_connection(ConnectionName) ->
    , keyfile    => Keyfile
   }.
 
+%% @doc Returns the gun's connection PID. This function is only used in tests.
+-spec gun_connection(name()) -> pid().
+gun_connection(ConnectionName) ->
+  gen_server:call(ConnectionName, gun_connection).
+
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================
 
 -spec init(connection()) -> {ok, State :: state()}.
 init(Connection) ->
-  Certfile = certfile(Connection),
-  Keyfile = keyfile(Connection),
-  Host = host(Connection),
-  Port = port(Connection),
-  TransportOpts = [{certfile, Certfile}, {keyfile, Keyfile}],
-  {ok, ConnPid} = gun:open(Host, Port, #{protocols => [http2]
-                                        , transport_opts => TransportOpts
-                                        }),
-  {ok, #{connection => Connection, gun_connection => ConnPid}}.
+  {GunMonitor, GunConnectionPid} = open_gun_connection(Connection),
+  {ok, #{ connection     => Connection
+        , gun_connection => GunConnectionPid
+        , gun_monitor    => GunMonitor
+        }}.
 
 -spec handle_call( Request :: term()
                  , From    :: {pid()
                  , Tag     :: term()}
                  , State
                  ) -> {reply, ok, State}.
+handle_call(gun_connection, _From, #{gun_connection := GunConn} = State) ->
+  {reply, GunConn, State};
 handle_call(_Request, _From, State) ->
   {reply, ok, State}.
 
@@ -118,6 +123,13 @@ handle_cast(_Request, State) ->
 
 -spec handle_info(Info :: timeout() | term(), State) ->
   {noreply, State}.
+handle_info( {'DOWN', GunMonitor, process, GunConnPid, _}
+           , #{ gun_connection := GunConnPid
+              , gun_monitor    := GunMonitor
+              , connection     := Connection
+              } = State) ->
+  {GunMonitor2, GunConnPid2} = open_gun_connection(Connection),
+  {noreply, State#{gun_connection => GunConnPid2, gun_monitor => GunMonitor2}};
 handle_info(_Info, State) ->
   {noreply, State}.
 
@@ -161,3 +173,20 @@ keyfile(#{keyfile := Keyfile}) ->
 %%%===================================================================
 %%% Internal Functions
 %%%===================================================================
+
+-spec open_gun_connection(connection()) -> { GunMonitor       :: reference()
+                                           , GunConnectionPid :: pid()
+                                           }.
+open_gun_connection(Connection) ->
+  Certfile = certfile(Connection),
+  Keyfile = keyfile(Connection),
+  Host = host(Connection),
+  Port = port(Connection),
+  TransportOpts = [{certfile, Certfile}, {keyfile, Keyfile}],
+  {ok, GunConnectionPid} = gun:open( Host
+                                   , Port
+                                   , #{ protocols => [http2]
+                                      , transport_opts => TransportOpts
+                                      }),
+  GunMonitor = monitor(process, GunConnectionPid),
+  {GunMonitor, GunConnectionPid}.

test/connection_SUITE.erl

@@ -8,6 +8,7 @@
 
 -export([ default_connection/1
         , connect/1
+        , gun_connection_crashes/1
         ]).
 
 -type config() :: [{atom(), term()}].
@@ -19,6 +20,7 @@
 -spec all() -> [atom()].
 all() ->  [ default_connection
           , connect
+          , gun_connection_crashes
           ].
 
 -spec init_per_suite(config()) -> config().
@@ -57,3 +59,32 @@ connect(_Config) ->
   true = is_process_alive(ServerPid),
   ServerPid = whereis(ConnectionName),
   ok.
+
+-spec gun_connection_crashes(config()) -> ok.
+gun_connection_crashes(_Config) ->
+  ok = meck:expect(gun, open, fun(_, _, _) ->
+      {ok, spawn(fun crash/0)}
+    end),
+  ConnectionName = my_connection2,
+  {ok, _ServerPid}  = apns:connect(ConnectionName),
+  GunPid = apns_connection:gun_connection(ConnectionName),
+  true = is_process_alive(GunPid),
+  GunPid ! crash,
+  timer:sleep(1000),
+  false = is_process_alive(GunPid),
+  GunPid2 = apns_connection:gun_connection(ConnectionName),
+  true = is_process_alive(GunPid2),
+  true = (GunPid =/= GunPid2),
+  [_] = meck:unload(),
+  ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Internal Functions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-spec crash() -> ok.
+crash() ->
+  receive
+    crash -> exit(crashed);
+    _     -> ok
+  end.