wx: Fix cleanup of event handlers

Event handlers was not removed after objects/process had been
delete/died, which causes memory leakage and that fun's was
kept in the wx_server process. Code that might be purged and
the server died.

1 files changed, 79 insertions, 39 deletions

diff --git a/lib/wx/src/wxe_server.erl b/lib/wx/src/wxe_server.erl
index a8604c76b9..45184a3bc8 100644
--- a/lib/wx/src/wxe_server.erl
+++ b/lib/wx/src/wxe_server.erl
@@ -36,7 +36,7 @@
 	 terminate/2, code_change/3]).
 
 -record(state, {port,cb_port,users,cleaners=[],cb,cb_cnt}).
--record(user,  {objects=[], events=[], evt_handler}).
+-record(user,  {events=[], evt_handler}).
 -record(event, {object, callback, cb_handler}).
 
 -define(APPLICATION, wxe).
@@ -157,26 +157,40 @@ handle_cast(_Msg, State) ->
 handle_info(Cb = {_, _, '_wx_invoke_cb_'}, State) ->
     invoke_cb(Cb, State),
     {noreply, State};
-handle_info({wx_delete_cb, FunId}, State0 = #state{cb=CB}) when is_integer(FunId) ->
-    case get(FunId) of
-	undefined ->
-	    {noreply, State0};
-	Fun ->
-	    erase(FunId),
-	    {noreply, State0#state{cb=gb_trees:delete(Fun, CB)}}
+
+handle_info({wx_delete_cb, FunId}, State)
+  when is_integer(FunId) ->
+    {noreply, delete_fun(FunId, State)};
+
+handle_info({wx_delete_cb, Id, EvtListener, Obj}, State = #state{users=Users}) ->
+    From = erase(EvtListener),
+    case gb_trees:lookup(From, Users) of
+	none ->
+	    {noreply, delete_fun(Id, State)};
+	{value, User0} ->
+	    User = cleanup_evt_listener(User0, EvtListener, Obj),
+	    {noreply, delete_fun(Id, State#state{users=gb_trees:update(From, User, Users)})}
     end;
+
 handle_info({'DOWN',_,process,Pid,_}, State=#state{users=Users0,cleaners=Cs}) ->
     try
 	User = gb_trees:get(Pid,Users0),
 	Users = gb_trees:delete(Pid,Users0),
 	Env = wx:get_env(),
-	Cleaner = spawn_link(fun() -> cleanup(Env,Pid,[User]) end),
-	{noreply, State#state{users=Users,cleaners=[Cleaner|Cs]}}
+	case User of
+	    #user{events=[], evt_handler=undefined} -> %% No need to spawn
+		{noreply, State#state{users=Users,cleaners=Cs}};
+	    _ ->
+		Cleaner = spawn_link(fun() -> cleanup(Env,Pid,[User]) end),
+		{noreply, State#state{users=Users,cleaners=[Cleaner|Cs]}}
+	end
     catch  _E:_R ->
 	    %% ?log("Error: ~p ~p", [_E,_R]),
 	    {noreply, State}
     end;
-handle_info(Msg = {'_wxe_destroy_', Pid}, State) ->
+
+handle_info(Msg = {'_wxe_destroy_', Pid}, State)
+  when is_pid(Pid) ->
     case erlang:is_process_alive(Pid) of
 	true ->
 	    Pid ! Msg,
@@ -185,6 +199,7 @@ handle_info(Msg = {'_wxe_destroy_', Pid}, State) ->
 	    ok
     end,
     {noreply, State};
+
 handle_info(_Info, State) ->
     ?log("Unknown message ~p sent to ~p~n",[_Info, ?MODULE]),
     {noreply, State}.
@@ -212,10 +227,10 @@ handle_connect(Object, EvData, From, State0 = #state{users=Users}) ->
 	    CBHandler = Handler0,
 	    Handler = Handler0;
 	undefined when Callback =:= 0 ->
-	    Handler = new_evt_listener(State0),
+	    Handler = new_evt_listener(State0, From),
 	    CBHandler = Handler;
 	_ ->
-	    CBHandler = new_evt_listener(State0),
+	    CBHandler = new_evt_listener(State0, From),
 	    Handler = Handler0
     end,
     Evs = [#event{object=Object,callback=Callback, cb_handler=CBHandler}|Evs0],
@@ -238,9 +253,9 @@ handle_connect(Object, EvData, From, State0 = #state{users=Users}) ->
 invoke_cb({{Ev=#wx{}, Ref=#wx_ref{}}, FunId,_}, _S) ->
     %% Event callbacks
     case get(FunId) of
-	Fun when is_function(Fun) ->
+	{Fun,_} when is_function(Fun) ->
 	    invoke_callback(fun() -> Fun(Ev, Ref), <<>> end);
-	Pid when is_pid(Pid) -> %% wx_object sync event
+	{Pid,_} when is_pid(Pid) -> %% wx_object sync event
 	    invoke_callback(Pid, Ev, Ref);
 	Err ->
 	    ?log("Internal Error ~p~n",[Err])
@@ -248,7 +263,7 @@ invoke_cb({{Ev=#wx{}, Ref=#wx_ref{}}, FunId,_}, _S) ->
 invoke_cb({FunId, Args, _}, _S) when is_list(Args), is_integer(FunId) ->
     %% Overloaded functions
     case get(FunId) of
-	Fun when is_function(Fun) ->
+	{Fun,_} when is_function(Fun) ->
 	    invoke_callback(fun() -> Fun(Args) end);
 	Err ->
 	    ?log("Internal Error ~p ~p ~p~n",[Err, FunId, Args])
@@ -311,10 +326,12 @@ get_wx_object_state(Pid) ->
 	_ -> ignore
     end.
 
-new_evt_listener(State) ->
+new_evt_listener(State, Owner) ->
     #wx_env{port=Port} = wx:get_env(),
     _ = erlang:port_control(Port,98,<<>>),
-    get_result(State).
+    Listener = get_result(State),
+    put(Listener, Owner),
+    Listener.
 
 get_result(_State) ->
     receive
@@ -326,43 +343,66 @@ get_result(_State) ->
 attach_fun(Fun, S = #state{cb=CB,cb_cnt=Next}) ->
     case gb_trees:lookup(Fun,CB) of
 	{value, ID} ->
+	    {Fun, N} = get(ID),
+	    put(ID, {Fun,N+1}),
 	    {ID,S};
 	none ->
-	    put(Next,Fun),
+	    put(Next,{Fun, 1}),
 	    {Next,S#state{cb=gb_trees:insert(Fun,Next,CB),cb_cnt=Next+1}}
     end.
 
+delete_fun(0, State) -> State;
+delete_fun(FunId, State = #state{cb=CB}) ->
+    case get(FunId) of
+	undefined ->
+	    State;
+	{Fun,N} when N < 2 ->
+	    erase(FunId),
+	    State#state{cb=gb_trees:delete(Fun, CB)};
+	{Fun,N} ->
+	    put(FunId, {Fun, N-1}),
+	    State
+    end.
+
+cleanup_evt_listener(U=#user{events=Evs0,evt_handler=Handler}, EvtListener, Object) ->
+    {Evs, Del} = lists:foldl(fun(#event{object=Obj,cb_handler=CBH}, {Acc, Delete})
+				   when CBH =:= EvtListener, Obj =:= Object ->
+				     {Acc, Delete};
+				(Event = #event{cb_handler=CBH}, {Acc, _Delete})
+				   when CBH =:= EvtListener ->
+				     {[Event|Acc], false};
+				(Event, {Acc, Delete}) ->
+				     {[Event|Acc], Delete}
+			     end, {[], true}, Evs0),
+    Del andalso wxEvtHandler:destroy_evt_listener(EvtListener),
+    case Del andalso Handler =:= EvtListener of
+	true ->
+	    U#user{events=Evs, evt_handler=undefined};
+	false ->
+	    U#user{events=Evs}
+    end.
+
 handle_disconnect(Object, Evh, From, State0 = #state{users=Users0}) ->
-    User0 = #user{events=Evs0, evt_handler=PidH} = gb_trees:get(From, Users0),
+    #user{events=Evs0} = gb_trees:get(From, Users0),
     Fun = wxEvtHandler:get_callback(Evh),
     case find_handler(Evs0, Object, Fun) of
-	[] ->
-	    {reply, false, State0};
+	[] -> {reply, false, State0};
 	Handlers ->
 	    case disconnect(Object,Evh, Handlers) of
-		Ev = #event{callback=CB, cb_handler=Handler} ->
-		    case is_function(CB) of
-			true ->  wxEvtHandler:destroy_evt_listener(Handler);
-			false -> ignore
-		    end,
-		    User = case lists:delete(Ev,Evs0) of
-			       [] when PidH =/= undefined ->
-				   wxEvtHandler:destroy_evt_listener(PidH),
-				   User0#user{events=[], evt_handler=undefined};
-			       Evs ->
-				   User0#user{events=Evs}
-			   end,
-		    {reply, true, State0#state{users=gb_trees:update(From,User,Users0)}};
+		#event{} ->
+		    {reply, true, State0};
 		Result ->
 		    {reply, Result, State0}
 	    end
     end.
 
 disconnect(Object,Evh,[Ev=#event{cb_handler=Handler}|Evs]) ->
-    case wxEvtHandler:disconnect_impl(Handler,Object,Evh) of
+    try wxEvtHandler:disconnect_impl(Handler,Object,Evh) of
 	true ->  Ev;
 	false -> disconnect(Object, Evh, Evs);
 	Error -> Error
+    catch _:_ ->
+	    false
     end;
 disconnect(_, _, []) -> false.
 
@@ -393,9 +433,9 @@ cleanup(Env, _Pid, Data) ->
     gen_server:cast(Env#wx_env.sv, {cleaned, self()}),
     normal.
 
-cleanup(#user{objects=_Os,events=Evs, evt_handler=Handler}) ->
-    lists:foreach(fun(#event{object=_O, callback=CB, cb_handler=CbH}) ->
-			  %%catch wxEvtHandler:disconnect_impl(CbH,O),
+cleanup(#user{events=Evs, evt_handler=Handler}) ->
+    lists:foreach(fun(#event{object=O, callback=CB, cb_handler=CbH}) ->
+			  catch wxEvtHandler:disconnect_impl(CbH,O),
 			  case is_function(CB) of
 			      true ->
 				  wxEvtHandler:destroy_evt_listener(CbH);