test.erl

-module(test).
-behaviour(gen_fsm).

-export([start_link/0]).
-export([init/1, checking/2,
         handle_event/3, handle_sync_event/4, handle_info/3,
         terminate/3, code_change/4]).

-define(TIMEOUT, 2000).

start_link() ->
    gen_fsm:start_link({local, ?MODULE}, ?MODULE, [], []).

%% ------------------------------------------------------------------
init([]) ->
    gen_fsm:start_timer(?TIMEOUT, []),
    {ok, checking, []}.

checking({timeout, _Ref, _Msg}, State) ->
    io:format("~p: I'm realy a timer!~n", [erlang:time()]),
    gen_fsm:start_timer(?TIMEOUT, []),
    {next_state, checking, State}.

handle_event(_Event, SN, SD) ->
    {next_state, SN, SD}.

handle_sync_event(_Event, _From, SN, SD) ->
    {next_state, SN, SD}.

handle_info(_Info, SN, SD) ->
    {next_state, SN, SD}.

terminate(_Reason, _SN, _SD) ->
    ok.

code_change(_OldVsn, SN, SD, _Extra) ->
    {ok, SN, SD}.