diff options
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 133 |
1 files changed, 68 insertions, 65 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index c02e6a1a19..6d7b461ee3 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -24,7 +24,7 @@ [start/3,start/4,start_link/3,start_link/4, stop/1,stop/3, cast/2,call/2,call/3, - enter_loop/5,enter_loop/6,enter_loop/7, + enter_loop/4,enter_loop/5,enter_loop/6, reply/1,reply/2]). %% gen callbacks @@ -63,8 +63,8 @@ {To :: pid(), Tag :: term()}. % Reply-to specifier for call -type state() :: - state_name() | % For state callback function StateName/5 - term(). % For state callback function handle_event/5 + state_name() | % For StateName/3 callback functios + term(). % For handle_event/4 callback function -type state_name() :: atom(). @@ -174,28 +174,33 @@ %% an {ok, ...} tuple. Thereafter the state callbacks are called %% for all events to this server. -callback init(Args :: term()) -> - {callback_mode(), state(), data()} | - {callback_mode(), state(), data(), [action()] | action()} | + {ok, state(), data()} | + {ok, state(), data(), [action()] | action()} | 'ignore' | {'stop', Reason :: term()}. -%% Example state callback for callback_mode() =:= state_functions -%% state name 'state_name'. +%% This callback shall return the callback mode of the callback module. %% -%% In this mode all states has to be type state_name() i.e atom(). +%% It is called once after init/0 and code_change/4 but before +%% the first state callback StateName/3 or handle_event/4. +-callback callback_mode() -> callback_mode(). + +%% Example state callback for StateName = 'state_name' +%% when callback_mode() =:= state_functions. +%% +%% In this mode all states has to be of type state_name() i.e atom(). %% -%% Note that state callbacks and only state callbacks have arity 5 -%% and that is intended. +%% Note that the only callbacks that have arity 3 are these +%% StateName/3 callbacks and terminate/3, so the state name +%% 'terminate' is unusable in this mode. -callback state_name( event_type(), EventContent :: term(), Data :: data()) -> state_function_result(). %% -%% State callback for callback_mode() =:= handle_event_function. -%% -%% Note that state callbacks and only state callbacks have arity 5 -%% and that is intended. +%% State callback for all states +%% when callback_mode() =:= handle_event_function. -callback handle_event( event_type(), EventContent :: term(), @@ -219,9 +224,7 @@ OldState :: state(), OldData :: data(), Extra :: term()) -> - {CallbackMode :: callback_mode(), - NewState :: state(), - NewData :: data()} | + {ok, NewState :: state(), NewData :: data()} | (Reason :: term()). %% Format the callback module state in some sensible that is @@ -240,10 +243,13 @@ [init/1, % One may use enter_loop/5,6,7 instead format_status/2, % Has got a default implementation %% - state_name/3, % Example for callback_mode =:= state_functions: - %% there has to be a StateName/5 callback function for every StateName. + state_name/3, % Example for callback_mode() =:= state_functions: + %% there has to be a StateName/3 callback function + %% for every StateName in your state machine but the state name + %% 'state_name' does of course not have to be used. %% - handle_event/4]). % For callback_mode =:= handle_event_function + handle_event/4 % For callback_mode() =:= handle_event_function + ]). %% Type validation functions callback_mode(CallbackMode) -> @@ -451,43 +457,35 @@ reply({To,Tag}, Reply) when is_pid(To) -> %% the same arguments as you would have returned from init/1 -spec enter_loop( Module :: module(), Opts :: [debug_opt()], - CallbackMode :: callback_mode(), State :: state(), Data :: data()) -> no_return(). -enter_loop(Module, Opts, CallbackMode, State, Data) -> - enter_loop(Module, Opts, CallbackMode, State, Data, self()). +enter_loop(Module, Opts, State, Data) -> + enter_loop(Module, Opts, State, Data, self()). %% -spec enter_loop( Module :: module(), Opts :: [debug_opt()], - CallbackMode :: callback_mode(), State :: state(), Data :: data(), Server_or_Actions :: server_name() | pid() | [action()]) -> no_return(). -enter_loop(Module, Opts, CallbackMode, State, Data, Server_or_Actions) -> +enter_loop(Module, Opts, State, Data, Server_or_Actions) -> if is_list(Server_or_Actions) -> - enter_loop( - Module, Opts, CallbackMode, State, Data, - self(), Server_or_Actions); + enter_loop(Module, Opts, State, Data, self(), Server_or_Actions); true -> - enter_loop( - Module, Opts, CallbackMode, State, Data, - Server_or_Actions, []) + enter_loop(Module, Opts, State, Data, Server_or_Actions, []) end. %% -spec enter_loop( Module :: module(), Opts :: [debug_opt()], - CallbackMode :: callback_mode(), State :: state(), Data :: data(), Server :: server_name() | pid(), Actions :: [action()] | action()) -> no_return(). -enter_loop(Module, Opts, CallbackMode, State, Data, Server, Actions) -> +enter_loop(Module, Opts, State, Data, Server, Actions) -> is_atom(Module) orelse error({atom,Module}), - callback_mode(CallbackMode) orelse error({callback_mode,CallbackMode}), Parent = gen:get_parent(), - enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent). + enter(Module, Opts, State, Data, Server, Actions, Parent). %%--------------------------------------------------------------------------- %% API helpers @@ -515,7 +513,7 @@ send(Proc, Msg) -> end. %% Here the init_it/6 and enter_loop/5,6,7 functions converge -enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) -> +enter(Module, Opts, State, Data, Server, Actions, Parent) -> %% The values should already have been type checked Name = gen:get_proc_name(Server), Debug = gen:debug_options(Name, Opts), @@ -531,7 +529,7 @@ enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) -> [Actions,{postpone,false}] end, S = #{ - callback_mode => CallbackMode, + callback_mode => undefined, module => Module, name => Name, %% All fields below will be replaced according to the arguments to @@ -569,30 +567,12 @@ init_it(Starter, Parent, ServerRef, Module, Args, Opts) -> init_result(Starter, Parent, ServerRef, Module, Result, Opts) -> case Result of - {CallbackMode,State,Data} -> - case callback_mode(CallbackMode) of - true -> - proc_lib:init_ack(Starter, {ok,self()}), - enter( - Module, Opts, CallbackMode, State, Data, - ServerRef, [], Parent); - false -> - Error = {callback_mode,CallbackMode}, - proc_lib:init_ack(Starter, {error,Error}), - exit(Error) - end; - {CallbackMode,State,Data,Actions} -> - case callback_mode(CallbackMode) of - true -> - proc_lib:init_ack(Starter, {ok,self()}), - enter( - Module, Opts, CallbackMode, State, Data, - ServerRef, Actions, Parent); - false -> - Error = {callback_mode,CallbackMode}, - proc_lib:init_ack(Starter, {error,Error}), - exit(Error) - end; + {ok,State,Data} -> + proc_lib:init_ack(Starter, {ok,self()}), + enter(Module, Opts, State, Data, ServerRef, [], Parent); + {ok,State,Data,Actions} -> + proc_lib:init_ack(Starter, {ok,self()}), + enter(Module, Opts, State, Data, ServerRef, Actions, Parent); {stop,Reason} -> gen:unregister_name(ServerRef), proc_lib:init_ack(Starter, {error,Reason}), @@ -631,11 +611,9 @@ system_code_change( Result -> Result end of - {CallbackMode,NewState,NewData} -> - callback_mode(CallbackMode) orelse - error({callback_mode,CallbackMode}), + {ok,NewState,NewData} -> {ok, - S#{callback_mode := CallbackMode, + S#{callback_mode := undefined, state := NewState, data := NewData}}; {ok,_} = Error -> @@ -859,6 +837,31 @@ loop_events_done(Parent, Debug, S, Timer, State, Data, P, Hibernate) -> loop_event( Parent, Debug, + #{callback_mode := undefined, + module := Module} = S, + Events, + State, Data, P, Event, Hibernate) -> + %% Cache the callback_mode() value + case + try Module:callback_mode() + catch + Result -> Result + end + of + CallbackMode -> + case callback_mode(CallbackMode) of + true -> + loop_event( + Parent, Debug, + S#{callback_mode := CallbackMode}, + Events, + State, Data, P, Event, Hibernate); + false -> + error({callback_mode,CallbackMode}) + end + end; +loop_event( + Parent, Debug, #{callback_mode := CallbackMode, module := Module} = S, Events, |