-module(hello_server2).
-behaviour(gen_server).
-compile(export_all).
%%% Start callback for supervisor
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
%%% gen_server callbacks
init([]) ->
{ok, sets:new()}.
handle_call({greet, Name}, _From, State) ->
io:format("Hello ~s!~n", [Name]),
NewState = sets:add_element(Name, State),
{reply, ok, NewState};
handle_call({bye, Name}, _From, State) ->
io:format("Goodbye ~s!~n", [Name]),
NewState = sets:del_element(Name, State),
{reply, ok, NewState}.
terminate(normal, State) ->
[io:format("Goodbye ~s!~n", [Name]) || Name <- State],
ok.
%%% Unused gen_server callbacks
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
handle_info(_Info, State) ->
{noreply, State}.
handle_cast(_Request, State) ->
{noreply, State}.
