gen_fsm demo

-module(code_lock).
-behaviour(gen_fsm).

-export([start_link/1,button/1]).
-export([locked/2,open/2,stop/0,sync_button/1]).

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


start_link(Code)->
	io:format("srart_link Code=~p~n",[Code]),
	gen_fsm:start_link({local,code_lock},code_lock,Code,[]).

button(Digit)-> 
	gen_fsm:send_event(code_lock,{button,Digit}).

init(Code)->
	io:format("init Code=~p~n",[Code]),
	{ok,locked,{[],Code}}.%sofar=[],Code=Code

sync_button(Digit)->
	gen_fsm:sync_send_event(code_lock, {button, Digit}).  


locked({button, Digit}, {SoFar, Code}) -> 
	io:format("locked {button,Digit}={button,~p},{SoFar,Code}=~p~n",[Digit,{SoFar,Code}]),
	io:format("[Digit|SoFar]=~p,Code=~p~n",[[Digit|SoFar],Code]),
	case [Digit|SoFar] of
		Code->
			do_unlock(),
			{next_state, open, {[], Code}, 3000};
 		Incomplete when length(Incomplete)
			io:format("length(Incomplete)=~p  <  length(Code)=~p~n",[length(Incomplete),length(Code)]),
           	 	{next_state, locked, {Incomplete, Code}};
        	_Wrong ->
			io:format("_Wrong~n"),
            		{next_state, locked, {[], Code}}
    	end.


open(timeout,State)->
	do_lock(),
	{next_state,locked,State}.

stop()->
	gen_fsm:send_all_state_event(code_lock,stop).




handle_event(stop,_StateName,StateData)->
	{stop,normal,StateData};
handle_event(_A,_B,_C)->
	{next_state,ok,ok}.

handle_sync_event({button,_Digit}, _From, StateName, State) -> 
   {reply,reply,StateName,State}.  

terminate(normal,_StateName,_StateData)->
	ok.


handle_info(_A, _B, _C) -> 
  {next_state, ok, ok}.



code_change(_A, _B, _C, _D) -> 
  {ok, ok, ok}. 



do_unlock()->  
    io:format("do_unlock~n").  
do_lock()->  
    io:format("do_lock~n").  

运行

2> c(code_lock).
{ok,code_lock}
3> code_lock:start_link([12]).
srart_link Code="\f"
init Code="\f"
{ok,<0.39.0>}
4> code_lock:button(3).
locked {button,Digit}={button,3},{SoFar,Code}={[],"\f"}
ok
[Digit|SoFar]=[3],Code="\f"
_Wrong
5> code_lock:button(12).
locked {button,Digit}={button,12},{SoFar,Code}={[],"\f"}
ok
[Digit|SoFar]="\f",Code="\f"
do_unlock
do_lock
6> code_lock:button(12).
locked {button,Digit}={button,12},{SoFar,Code}={[],"\f"}
ok
[Digit|SoFar]="\f",Code="\f"
do_unlock
do_lock
7>