gen_server.erl

-module(module_name).
-behaviour(gen_server).

%% gen_server callbacks
-export([start_link/0, init/1, handle_call/3, handle_cast/2, 
	     handle_info/2, terminate/2, code_change/3]).

%% API functions
start_link() ->
	gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).

%%====================================================================
%% gen_server callbacks
%%====================================================================

%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%%                         {ok, State, Timeout} |
%%                         ignore               |
%%                         {stop, Reason}
%% Description: Initiates the server
%% @hidden
%%--------------------------------------------------------------------
init([]) ->
	{ok,[]}.

%%--------------------------------------------------------------------
%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
%%                                      {reply, Reply, State, Timeout} |
%%                                      {noreply, State} |
%%                                      {noreply, State, Timeout} |
%%                                      {stop, Reason, Reply, State} |
%%                                      {stop, Reason, State}
%% Description: Handling call messages
%% @hidden
%%--------------------------------------------------------------------    
handle_call(_Msg, _From, State) -> {reply, {error, invalid_call}, State}.

%%--------------------------------------------------------------------
%% Function: handle_cast(Msg, State) -> {noreply, State} |
%%                                      {noreply, State, Timeout} |
%%                                      {stop, Reason, State}
%% Description: Handling cast messages
%% @hidden
%%--------------------------------------------------------------------
handle_cast(_Msg, State) -> {noreply, State}.

%%--------------------------------------------------------------------
%% Function: handle_info(Info, State) -> {noreply, State} |
%%                                       {noreply, State, Timeout} |
%%                                       {stop, Reason, State}
%% Description: Handling all non call/cast messages
%% @hidden
%%--------------------------------------------------------------------
handle_info(_Info, State) -> {noreply, State}.

%%--------------------------------------------------------------------
%% Function: terminate(Reason, State) -> void()
%% Description: This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any necessary
%% cleaning up. When it returns, the gen_server terminates with Reason.
%% The return value is ignored.
%% @hidden
%%--------------------------------------------------------------------
terminate(_Reason, _State) -> 
    ok.

%%--------------------------------------------------------------------
%% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
%% Description: Convert process state when code is changed
%% @hidden
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) -> {ok, State}.

%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------