在gen_server中实现定时功能（方法一）

转载请注明，来自：http://blog.csdn.net/skyman_2001

使用erlang:send_after()函数，代码如下：

-module(otp_test). -behaviour(gen_server). -export([start_link/0]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -define(INTERVAL, 5000). start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). init([]) -> %% Note we must set trap_exit = true if we %% want terminate/2 to be called when the application %% is stopped process_flag(trap_exit, true), io:format("~p starting~n",[?MODULE]), erlang:send_after(?INTERVAL, self(), {trigger, 0}), {ok, 0}. handle_call(_Msg, _From, State) -> {noreply, State}. handle_cast(_Msg, State) -> {noreply, State}. handle_info({trigger, N}, State) -> io:format("tick ~p~n", [N]), erlang:send_after(?INTERVAL, self(), {trigger, N+1}), {noreply, State}. terminate(_Reason, _State) -> io:format("~p stopping~n",[?MODULE]), ok. code_change(_OldVsn, State, _Extra) -> {ok, State}.

运行:

otp_test:start_link().

结果：

otp_test starting {ok,<0.59.0>} tick 0 tick 1 tick 2 tick 3 tick 4 tick 5 tick 6 tick 7 tick 8 tick 9 tick 10 ...