diff options
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 8 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 493 | ||||
| -rw-r--r-- | lib/stdlib/test/gen_statem_SUITE.erl | 10 | ||||
| -rw-r--r-- | system/doc/design_principles/code_lock.dia | bin | 2955 -> 2932 bytes | |||
| -rw-r--r-- | system/doc/design_principles/code_lock.png | bin | 58823 -> 59160 bytes | |||
| -rw-r--r-- | system/doc/design_principles/code_lock_2.dia | bin | 2646 -> 2621 bytes | |||
| -rw-r--r-- | system/doc/design_principles/code_lock_2.png | bin | 51848 -> 48927 bytes | |||
| -rw-r--r-- | system/doc/design_principles/fsm.xml | 2 |
8 files changed, 280 insertions, 233 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 4fe940bd05..be90488a1f 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -411,21 +411,21 @@ handle_event(_, _, State, Data) -> The <c>gen_statem</c> is locally registered. </p> </item> - <tag><c>Name, Node</c></tag> + <tag><c>{Name,Node}</c></tag> <item> <p> The <c>gen_statem</c> is locally registered on another node. </p> </item> - <tag><c>GlobalName</c></tag> + <tag><c>{global,GlobalName}</c></tag> <item> <p> The <c>gen_statem</c> is globally registered in <seealso marker="kernel:global"><c>kernel:global</c></seealso>. </p> </item> - <tag><c>RegMod, ViaName</c></tag> + <tag><c>{via,RegMod,ViaName}</c></tag> <item> <p> The <c>gen_statem</c> is registered through @@ -906,7 +906,7 @@ handle_event(_, _, State, Data) -> <tag><c>stop</c></tag> <item> <p> - Terminates the <c>gen_statem</c> by calling + Terminates the <c>gen_statem</c> by calling <seealso marker="#Module:terminate/3"> <c>Module:terminate/3</c> </seealso> diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index f9e2e5f7d2..23bddafeed 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -97,7 +97,7 @@ %% * Postponing the current event is performed %% iff 'postpone' is 'true'. %% * A state timer is started iff 'timeout' is set. - %% * Pending events are processed or if there are + %% * Pending events are handled or if there are %% no pending events the server goes into receive %% or hibernate (iff 'hibernate' is 'true') %% @@ -282,16 +282,6 @@ event_type(Type) -> STACKTRACE(), try throw(ok) catch _ -> erlang:get_stacktrace() end). --define( - TERMINATE(Class, Reason, Debug, S, Q), - terminate( - begin Class end, - begin Reason end, - ?STACKTRACE(), - begin Debug end, - begin S end, - begin Q end)). - %%%========================================================================== %%% API @@ -300,11 +290,11 @@ event_type(Type) -> | {'via', RegMod :: module(), Name :: term()} | {'local', atom()}. -type server_ref() :: - {'global', GlobalName :: term()} - | {'via', RegMod :: module(), ViaName :: term()} + pid() | (LocalName :: atom()) | {Name :: atom(), Node :: atom()} - | pid(). + | {'global', GlobalName :: term()} + | {'via', RegMod :: module(), ViaName :: term()}. -type debug_opt() :: {'debug', Dbgs :: @@ -523,12 +513,15 @@ send(Proc, Msg) -> ok end. -%% Here init_it/6 and enter_loop/5,6,7 functions converge +%% Here the init_it/6 and enter_loop/5,6,7 functions converge enter(Module, Opts, CallbackMode, 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), - PrevState = make_ref(), % Will be discarded by loop_event_actions/9 + P = Events = [], + Event = {internal,initial_state}, + %% We enforce {postpone,false} to ensure that + %% our fake Event gets discarded, thought it might get logged NewActions = if is_list(Actions) -> @@ -540,15 +533,17 @@ enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) -> callback_mode => CallbackMode, module => Module, name => Name, - state => PrevState, + %% All fields below will be replaced according to the arguments to + %% loop_event_actions/10 when it finally loops back to loop/3 + state => State, data => Data, - timer => undefined, - postponed => [], - hibernate => false}, + postponed => P, + hibernate => false, + timer => undefined}, + NewDebug = sys_debug(Debug, S, State, {enter,Event,State}), loop_event_actions( - Parent, Debug, S, [], - {event,undefined}, % Will be discarded thanks to {postpone,false} - PrevState, State, Data, NewActions). + Parent, NewDebug, S, Events, + State, Data, P, Event, State, NewActions). %%%========================================================================== %%% gen callbacks @@ -617,8 +612,12 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) -> system_continue(Parent, Debug, S) -> loop(Parent, Debug, S). -system_terminate(Reason, _Parent, Debug, S) -> - ?TERMINATE(exit, Reason, Debug, S, []). +system_terminate( + Reason, _Parent, Debug, + #{state := State, data := Data, postponed := P} = S) -> + terminate( + exit, Reason, ?STACKTRACE(), + Debug, S, [], State, Data, P). system_code_change( #{module := Module, @@ -634,7 +633,10 @@ system_code_change( {NewCallbackMode,NewState,NewData} -> callback_mode(NewCallbackMode) orelse error({callback_mode,NewCallbackMode}), - {ok,S#{state := NewState, data := NewData}}; + {ok, + S#{callback_mode := NewCallbackMode, + state := NewState, + data := NewData}}; {ok,_} = Error -> error({case_clause,Error}); Error -> @@ -654,7 +656,7 @@ system_replace_state( format_status( Opt, [PDict,SysState,Parent,Debug, - #{name := Name, postponed := P} = S]) -> + #{name := Name, postponed := P, state := State, data := Data} = S]) -> Header = gen:format_status_header("Status for state machine", Name), Log = sys:get_debug(log, Debug, []), [{header,Header}, @@ -663,7 +665,7 @@ format_status( {"Parent",Parent}, {"Logged Events",Log}, {"Postponed",P}]} | - case format_status(Opt, PDict, S) of + case format_status(Opt, PDict, S, State, Data) of L when is_list(L) -> L; T -> [T] end]. @@ -673,21 +675,21 @@ format_status( %% them, not as the real erlang messages. Use trace for that. %%--------------------------------------------------------------------------- -print_event(Dev, {in,Event}, #{name := Name}) -> +print_event(Dev, {in,Event}, {Name,_}) -> io:format( Dev, "*DBG* ~p received ~s~n", [Name,event_string(Event)]); -print_event(Dev, {out,Reply,{To,_Tag}}, #{name := Name}) -> +print_event(Dev, {out,Reply,{To,_Tag}}, {Name,_}) -> io:format( Dev, "*DBG* ~p sent ~p to ~p~n", [Name,Reply,To]); -print_event(Dev, {Tag,Event,NewState}, #{name := Name, state := State}) -> +print_event(Dev, {Tag,Event,NextState}, {Name,State}) -> StateString = - case NewState of + case NextState of State -> io_lib:format("~p", [State]); _ -> - io_lib:format("~p => ~p", [State,NewState]) + io_lib:format("~p => ~p", [State,NextState]) end, io:format( Dev, "*DBG* ~p ~w ~s in state ~s~n", @@ -697,16 +699,17 @@ event_string(Event) -> case Event of {{call,{Pid,_Tag}},Request} -> io_lib:format("call ~p from ~w", [Request,Pid]); - {Tag,Content} -> - io_lib:format("~w ~p", [Tag,Content]) + {EventType,EventContent} -> + io_lib:format("~w ~p", [EventType,EventContent]) end. -sys_debug(Debug, S, Entry) -> +sys_debug(Debug, #{name := Name}, State, Entry) -> case Debug of [] -> Debug; _ -> - sys:handle_debug(Debug, fun print_event/3, S, Entry) + sys:handle_debug( + Debug, fun print_event/3, {Name,State}, Entry) end. %%%========================================================================== @@ -720,7 +723,7 @@ wakeup_from_hibernate(Parent, Debug, S) -> %%% State Machine engine implementation of proc_lib/gen server %% Server loop, consists of all loop* functions -%% and some detours through sys and proc_lib +%% and detours through sys:handle_system_message/7 and proc_lib:hibernate/3 %% Entry point for system_continue/3 loop(Parent, Debug, #{hibernate := Hibernate} = S) -> @@ -749,12 +752,16 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) -> sys:handle_system_msg( Req, Pid, Parent, ?MODULE, Debug, S, Hibernate); {'EXIT',Parent,Reason} = EXIT -> + #{state := State, data := Data, postponed := P} = S, %% EXIT is not a 2-tuple and therefore %% not an event and has no event_type(), %% but this will stand out in the crash report... - ?TERMINATE(exit, Reason, Debug, S, [EXIT]); + terminate( + exit, Reason, ?STACKTRACE(), + Debug, S, [EXIT], State, Data, P); {timeout,Timer,Content} when Timer =/= undefined -> - loop_event(Parent, Debug, S, {timeout,Content}); + loop_receive_result( + Parent, Debug, S, {timeout,Content}); _ -> %% Cancel Timer if running case Timer of @@ -782,30 +789,81 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) -> _ -> {info,Msg} end, - loop_event(Parent, Debug, S, Event) + loop_receive_result(Parent, Debug, S, Event) end end. -loop_event(Parent, Debug, S, Event) -> - %% The timer field and the hibernate flag in S - %% are now invalid and ignored until we get back to loop/3 - NewDebug = sys_debug(Debug, S, {in,Event}), - %% Here the queue of not yet processed events is created - loop_events(Parent, NewDebug, S, [Event], false). - -%% Process first the event queue, or if it is empty -%% loop back to receive a new event -loop_events(Parent, Debug, S, [], _Hibernate) -> - loop(Parent, Debug, S); +loop_receive_result( + Parent, Debug, + #{state := State, + data := Data, + postponed := P} = S, + Event) -> + %% The engine state map S is now dismantled + %% and will not be restored until we return to loop/3. + %% + %% The fields 'callback_mode', 'module', and 'name' are still valid. + %% The fields 'state', 'data', and 'postponed' are held in arguments. + %% The fields 'timer' and 'hibernate' will be recalculated. + %% + NewDebug = sys_debug(Debug, S, State, {in,Event}), + %% Here the queue of not yet handled events is created + Events = [], + Hibernate = false, + loop_event( + Parent, NewDebug, S, Events, State, Data, P, Event, Hibernate). + +%% Process the event queue, or if it is empty +%% loop back to loop/3 to receive a new event +loop_events( + Parent, Debug, S, [Event|Events], + State, Data, P, Hibernate, _Timeout) -> + %% + %% If there was a state timer requested we just ignore that + %% since we have events to handle which cancels the timer + loop_event( + Parent, Debug, S, Events, State, Data, P, Event, Hibernate); loop_events( + Parent, Debug, S, [], + State, Data, P, Hibernate, Timeout) -> + case Timeout of + {timeout,0,EventContent} -> + %% Immediate timeout - simulate it + %% so we do not get the timeout message + %% after any received event + loop_event( + Parent, Debug, S, [], + State, Data, P, {timeout,EventContent}, Hibernate); + {timeout,Time,EventContent} -> + %% Actually start a timer + Timer = erlang:start_timer(Time, self(), EventContent), + loop_events_done( + Parent, Debug, S, Timer, State, Data, P, Hibernate); + undefined -> + %% No state timeout has been requested + Timer = undefined, + loop_events_done( + Parent, Debug, S, Timer, State, Data, P, Hibernate) + end. +%% +loop_events_done(Parent, Debug, S, Timer, State, Data, P, Hibernate) -> + NewS = + S#{ + state := State, + data := Data, + postponed := P, + hibernate := Hibernate, + timer := Timer}, + loop(Parent, Debug, NewS). + +loop_event( Parent, Debug, #{callback_mode := CallbackMode, - module := Module, - state := State, - data := Data} = S, - [{Type,Content} = Event|Events] = Q, - Hibernate) -> - %% If the Hibernate flag is true here it can only be + module := Module} = S, + Events, + State, Data, P, {Type,Content} = Event, Hibernate) -> + %% + %% If Hibernate is true here it can only be %% because it was set from an event action %% and we did not go into hibernation since there %% were events in queue, so we do what the user @@ -813,6 +871,7 @@ loop_events( %% would have happened if we actually hibernated %% and immediately was awakened Hibernate andalso garbage_collect(), + %% try case CallbackMode of state_functions -> @@ -822,11 +881,11 @@ loop_events( end of Result -> loop_event_result( - Parent, Debug, S, Events, Event, Result) + Parent, Debug, S, Events, State, Data, P, Event, Result) catch Result -> loop_event_result( - Parent, Debug, S, Events, Event, Result); + Parent, Debug, S, Events, State, Data, P, Event, Result); error:badarg when CallbackMode =:= state_functions -> case erlang:get_stacktrace() of [{erlang,apply,[Module,State,_],_}|Stacktrace] -> @@ -835,9 +894,11 @@ loop_events( error, {undef_state_function,{Module,State,Args}}, Stacktrace, - Debug, S, Q); + Debug, S, [Event|Events], State, Data, P); Stacktrace -> - terminate(error, badarg, Stacktrace, Debug, S, Q) + terminate( + error, badarg, Stacktrace, + Debug, S, [Event|Events], State, Data, P) end; error:undef -> %% Process an undef to check for the simple mistake @@ -852,7 +913,7 @@ loop_events( error, {undef_state_function,{Module,State,Args}}, Stacktrace, - Debug, S, Q); + Debug, S, [Event|Events], State, Data, P); [{Module,handle_event, [Type,Content,State,Data]=Args, _} @@ -860,86 +921,85 @@ loop_events( when CallbackMode =:= handle_event_function -> terminate( error, - {undef_state_function, - {Module,handle_event,Args}}, + {undef_state_function,{Module,handle_event,Args}}, Stacktrace, - Debug, S, Q); + Debug, S, [Event|Events], State, Data, P); Stacktrace -> - terminate(error, undef, Stacktrace, Debug, S, Q) + terminate( + error, undef, Stacktrace, + Debug, S, [Event|Events], State, Data, P) end; Class:Reason -> Stacktrace = erlang:get_stacktrace(), - terminate(Class, Reason, Stacktrace, Debug, S, Q) + terminate( + Class, Reason, Stacktrace, + Debug, S, [Event|Events], State, Data, P) end. %% Interpret all callback return variants loop_event_result( - Parent, Debug, - #{state := State, data := Data} = S, - Events, Event, Result) -> - %% From now until we loop back to the loop_events/4 - %% the state and data fields in S are old + Parent, Debug, S, Events, State, Data, P, Event, Result) -> case Result of stop -> - ?TERMINATE(exit, normal, Debug, S, [Event|Events]); + terminate( + exit, normal, ?STACKTRACE(), + Debug, S, [Event|Events], State, Data, P); {stop,Reason} -> - ?TERMINATE(exit, Reason, Debug, S, [Event|Events]); + terminate( + exit, Reason, ?STACKTRACE(), + Debug, S, [Event|Events], State, Data, P); {stop,Reason,NewData} -> - NewS = S#{data := NewData}, - Q = [Event|Events], - ?TERMINATE(exit, Reason, Debug, NewS, Q); + terminate( + exit, Reason, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P); {stop_and_reply,Reason,Replies} -> Q = [Event|Events], - [Class,NewReason,Stacktrace,NewDebug] = - reply_then_terminate( - exit, Reason, ?STACKTRACE(), Debug, S, Q, Replies), - %% Since we got back here Replies was bad - terminate(Class, NewReason, Stacktrace, NewDebug, S, Q); + reply_then_terminate( + exit, Reason, ?STACKTRACE(), + Debug, S, Q, State, Data, P, Replies); {stop_and_reply,Reason,Replies,NewData} -> - NewS = S#{data := NewData}, Q = [Event|Events], - [Class,NewReason,Stacktrace,NewDebug] = - reply_then_terminate( - exit, Reason, ?STACKTRACE(), Debug, NewS, Q, Replies), - %% Since we got back here Replies was bad - terminate(Class, NewReason, Stacktrace, NewDebug, NewS, Q); + reply_then_terminate( + exit, Reason, ?STACKTRACE(), + Debug, S, Q, State, NewData, P, Replies); {next_state,NextState,NewData} -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, []); + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, []); {next_state,NextState,NewData,Actions} -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions); + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions); {keep_state,NewData} -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, State, NewData, []); + Parent, Debug, S, Events, + State, NewData, P, Event, State, []); {keep_state,NewData,Actions} -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, State, NewData, Actions); + Parent, Debug, S, Events, + State, NewData, P, Event, State, Actions); keep_state_and_data -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, State, Data, []); + Parent, Debug, S, Events, + State, Data, P, Event, State, []); {keep_state_and_data,Actions} -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, State, Data, Actions); + Parent, Debug, S, Events, + State, Data, P, Event, State, Actions); _ -> - ?TERMINATE( - error, {bad_return_value,Result}, Debug, S, [Event|Events]) + terminate( + error, {bad_return_value,Result}, ?STACKTRACE(), + Debug, S, [Event|Events], State, Data, P) end. loop_event_actions( - Parent, Debug, S, Events, Event, State, NextState, NewData, Actions) -> - Postpone = false, % Shall we postpone this event, true or false + Parent, Debug, S, Events, State, NewData, P, Event, NextState, Actions) -> + Postpone = false, % Shall we postpone this event; boolean() Hibernate = false, Timeout = undefined, NextEvents = [], loop_event_actions( - Parent, Debug, S, Events, Event, State, NextState, NewData, + Parent, Debug, S, Events, State, NewData, P, Event, NextState, if is_list(Actions) -> Actions; @@ -948,97 +1008,103 @@ loop_event_actions( end, Postpone, Hibernate, Timeout, NextEvents). %% -%% Process all action()s +%% Process all actions loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, [Action|Actions], + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, [Action|Actions], Postpone, Hibernate, Timeout, NextEvents) -> case Action of %% Actual actions {reply,From,Reply} -> case from(From) of true -> - NewDebug = do_reply(Debug, S, From, Reply), + NewDebug = do_reply(Debug, S, State, From, Reply), loop_event_actions( - Parent, NewDebug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, NewDebug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, Hibernate, Timeout, NextEvents); false -> - ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]) + terminate( + error, {bad_action,Action}, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P) end; {next_event,Type,Content} -> case event_type(Type) of true -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, Hibernate, Timeout, [{Type,Content}|NextEvents]); false -> - ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]) + terminate( + error, {bad_action,Action}, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P) end; %% Actions that set options {postpone,NewPostpone} when is_boolean(NewPostpone) -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, NewPostpone, Hibernate, Timeout, NextEvents); {postpone,_} -> - ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]); + terminate( + error, {bad_action,Action}, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P); postpone -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, true, Hibernate, Timeout, NextEvents); {hibernate,NewHibernate} when is_boolean(NewHibernate) -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, NewHibernate, Timeout, NextEvents); {hibernate,_} -> - ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]); + terminate( + error, {bad_action,Action}, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P); hibernate -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, true, Timeout, NextEvents); {timeout,infinity,_} -> % Clear timer - it will never trigger loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, Hibernate, undefined, NextEvents); {timeout,Time,_} = NewTimeout when is_integer(Time), Time >= 0 -> loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, Hibernate, NewTimeout, NextEvents); {timeout,_,_} -> - ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]); + terminate( + error, {bad_action,Action}, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P); infinity -> % Clear timer - it will never trigger loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, Hibernate, undefined, NextEvents); Time when is_integer(Time), Time >= 0 -> NewTimeout = {timeout,Time,Time}, loop_event_actions( - Parent, Debug, S, Events, Event, - State, NextState, NewData, Actions, + Parent, Debug, S, Events, + State, NewData, P, Event, NextState, Actions, Postpone, Hibernate, NewTimeout, NextEvents); _ -> - ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]) + terminate( + error, {bad_action,Action}, ?STACKTRACE(), + Debug, S, [Event|Events], State, NewData, P) end; %% %% End of actions list loop_event_actions( - Parent, Debug, #{postponed := P0} = S, Events, Event, - State, NextState, NewData, [], + Parent, Debug, S, Events, + State, NewData, P0, Event, NextState, [], Postpone, Hibernate, Timeout, NextEvents) -> %% %% All options have been collected and next_events are buffered. @@ -1059,89 +1125,62 @@ loop_event_actions( {lists:reverse(P1, Events),[]} end, %% Place next events first in queue - Q3 = lists:reverse(NextEvents, Q2), + Q = lists:reverse(NextEvents, Q2), %% NewDebug = sys_debug( - Debug, S, + Debug, S, State, case Postpone of true -> {postpone,Event,NextState}; false -> {consume,Event,NextState} end), - %% Have a peek on the event queue so we can avoid starting - %% the state timer unless we have to - {Q,Timer} = - case Timeout of - undefined -> - %% No state timeout has been requested - {Q3,undefined}; - {timeout,Time,EventContent} -> - %% A state timeout has been requested - case Q3 of - [] when Time =:= 0 -> - %% Immediate timeout - simulate it - %% so we do not get the timeout message - %% after any received event - {[{timeout,EventContent}],undefined}; - [] -> - %% Actually start a timer - {Q3,erlang:start_timer(Time, self(), EventContent)}; - _ -> - %% Do not start a timer since any queued - %% event cancels the state timer so we pretend - %% that the timer has been started and cancelled - {Q3,undefined} - end - end, - %% Loop to top of event queue loop; process next event loop_events( - Parent, NewDebug, - S#{ - state := NextState, - data := NewData, - timer := Timer, - postponed := P, - hibernate := Hibernate}, - Q, Hibernate). + Parent, NewDebug, S, Q, NextState, NewData, P, Hibernate, Timeout). %%--------------------------------------------------------------------------- %% Server helpers -reply_then_terminate(Class, Reason, Stacktrace, Debug, S, Q, Replies) -> +reply_then_terminate( + Class, Reason, Stacktrace, + Debug, S, Q, State, Data, P, Replies) -> if is_list(Replies) -> do_reply_then_terminate( - Class, Reason, Stacktrace, Debug, S, Q, Replies); + Class, Reason, Stacktrace, + Debug, S, Q, State, Data, P, Replies); true -> do_reply_then_terminate( - Class, Reason, Stacktrace, Debug, S, Q, [Replies]) + Class, Reason, Stacktrace, + Debug, S, Q, State, Data, P, [Replies]) end. %% -do_reply_then_terminate(Class, Reason, Stacktrace, Debug, S, Q, []) -> - terminate(Class, Reason, Stacktrace, Debug, S, Q); do_reply_then_terminate( - Class, Reason, Stacktrace, Debug, S, Q, [R|Rs]) -> + Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, []) -> + terminate(Class, Reason, Stacktrace, Debug, S, Q, State, Data, P); +do_reply_then_terminate( + Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, [R|Rs]) -> case R of {reply,{_To,_Tag}=From,Reply} -> - NewDebug = do_reply(Debug, S, From, Reply), + NewDebug = do_reply(Debug, S, State, From, Reply), do_reply_then_terminate( - Class, Reason, Stacktrace, NewDebug, S, Q, Rs); + Class, Reason, Stacktrace, + NewDebug, S, Q, State, Data, P, Rs); _ -> - [error,{bad_action,R},?STACKTRACE(),Debug] + terminate( + error, {bad_action,R}, ?STACKTRACE(), + Debug, S, Q, State, Data, P) end. -do_reply(Debug, S, From, Reply) -> +do_reply(Debug, S, State, From, Reply) -> reply(From, Reply), - sys_debug(Debug, S, {out,Reply,From}). + sys_debug(Debug, S, State, {out,Reply,From}). terminate( - Class, Reason, Stacktrace, Debug, - #{module := Module, - state := State, data := Data} = S, - Q) -> + Class, Reason, Stacktrace, + Debug, #{module := Module} = S, Q, State, Data, P) -> try Module:terminate(Reason, State, Data) of _ -> ok catch @@ -1149,8 +1188,8 @@ terminate( C:R -> ST = erlang:get_stacktrace(), error_info( - C, R, ST, Debug, S, Q, - format_status(terminate, get(), S)), + C, R, ST, Debug, S, Q, P, + format_status(terminate, get(), S, State, Data)), erlang:raise(C, R, ST) end, case Reason of @@ -1159,8 +1198,8 @@ terminate( {shutdown,_} -> ok; _ -> error_info( - Class, Reason, Stacktrace, Debug, S, Q, - format_status(terminate, get(), S)) + Class, Reason, Stacktrace, Debug, S, Q, P, + format_status(terminate, get(), S, State, Data)) end, case Stacktrace of [] -> @@ -1171,9 +1210,8 @@ terminate( error_info( Class, Reason, Stacktrace, Debug, - #{name := Name, callback_mode := CallbackMode, - state := State, postponed := P}, - Q, FmtData) -> + #{name := Name, callback_mode := CallbackMode}, + Q, P, FmtData) -> {FixedReason,FixedStacktrace} = case Stacktrace of [{M,F,Args,_}|ST] @@ -1202,46 +1240,49 @@ error_info( error_logger:format( "** State machine ~p terminating~n" ++ case Q of - [] -> - ""; - _ -> - "** Last event = ~p~n" + [] -> ""; + _ -> "** Last event = ~p~n" end ++ - "** When Server state = ~p~n" ++ + "** When server state = ~p~n" ++ "** Reason for termination = ~w:~p~n" ++ - "** State = ~p~n" ++ "** Callback mode = ~p~n" ++ - "** Queued/Postponed = ~w/~w~n" ++ + case Q of + [_,_|_] -> "** Queued = ~p~n"; + _ -> "" + end ++ + case P of + [] -> ""; + _ -> "** Postponed = ~p~n" + end ++ case FixedStacktrace of - [] -> - ""; - _ -> - "** Stacktrace =~n" - "** ~p~n" + [] -> ""; + _ -> "** Stacktrace =~n** ~p~n" end, [Name | case Q of - [] -> - []; - [Event|_] -> - [Event] + [] -> []; + [Event|_] -> [Event] end] ++ [FmtData,Class,FixedReason, - State,CallbackMode,length(Q),length(P)] ++ + CallbackMode] ++ + case Q of + [_|[_|_] = Events] -> [Events]; + _ -> [] + end ++ + case P of + [] -> []; + _ -> [P] + end ++ case FixedStacktrace of - [] -> - []; - _ -> - [FixedStacktrace] + [] -> []; + _ -> [FixedStacktrace] end), sys:print_log(Debug), ok. %% Call Module:format_status/2 or return a default value -format_status( - Opt, PDict, - #{module := Module, state := State, data := Data}) -> +format_status(Opt, PDict, #{module := Module}, State, Data) -> case erlang:function_exported(Module, format_status, 2) of true -> try Module:format_status(Opt, [PDict,State,Data]) diff --git a/lib/stdlib/test/gen_statem_SUITE.erl b/lib/stdlib/test/gen_statem_SUITE.erl index 3deb5fd986..364314f91b 100644 --- a/lib/stdlib/test/gen_statem_SUITE.erl +++ b/lib/stdlib/test/gen_statem_SUITE.erl @@ -634,12 +634,14 @@ sys1(Config) -> stop_it(Pid). code_change(Config) -> + Mode = handle_event_function, {ok,Pid} = gen_statem:start(?MODULE, start_arg(Config, []), []), {idle,data} = sys:get_state(Pid), sys:suspend(Pid), - sys:change_code(Pid, ?MODULE, old_vsn, state_functions), + sys:change_code(Pid, ?MODULE, old_vsn, Mode), sys:resume(Pid), - {idle,{old_vsn,data,state_functions}} = sys:get_state(Pid), + {idle,{old_vsn,data,Mode}} = sys:get_state(Pid), + Mode = gen_statem:call(Pid, get_callback_mode), stop_it(Pid). call_format_status(Config) -> @@ -1478,6 +1480,8 @@ next_events(Type, Content, Data) -> end. +handle_common_events({call,From}, get_callback_mode, _, _) -> + {keep_state_and_data,{reply,From,state_functions}}; handle_common_events({call,From}, get, State, Data) -> {keep_state,Data, [{reply,From,{state,State,Data}}]}; @@ -1501,6 +1505,8 @@ handle_common_events(cast, {'alive?',Pid}, _, Data) -> handle_common_events(_, _, _, _) -> undefined. +handle_event({call,From}, get_callback_mode, _, _) -> + {keep_state_and_data,{reply,From,handle_event_function}}; %% Wrapper state machine that uses a map state machine spec handle_event( Type, Event, State, [Data|Machine]) diff --git a/system/doc/design_principles/code_lock.dia b/system/doc/design_principles/code_lock.dia Binary files differindex bed6d8ee86..8e6ff8a898 100644 --- a/system/doc/design_principles/code_lock.dia +++ b/system/doc/design_principles/code_lock.dia diff --git a/system/doc/design_principles/code_lock.png b/system/doc/design_principles/code_lock.png Binary files differindex e40f0320aa..745fd91920 100644 --- a/system/doc/design_principles/code_lock.png +++ b/system/doc/design_principles/code_lock.png diff --git a/system/doc/design_principles/code_lock_2.dia b/system/doc/design_principles/code_lock_2.dia Binary files differindex 4e82a9e1d6..142909a2f5 100644 --- a/system/doc/design_principles/code_lock_2.dia +++ b/system/doc/design_principles/code_lock_2.dia diff --git a/system/doc/design_principles/code_lock_2.png b/system/doc/design_principles/code_lock_2.png Binary files differindex 138fbdef6c..ecf7b0d799 100644 --- a/system/doc/design_principles/code_lock_2.png +++ b/system/doc/design_principles/code_lock_2.png diff --git a/system/doc/design_principles/fsm.xml b/system/doc/design_principles/fsm.xml index 3468f93ae0..4f2b75e6e8 100644 --- a/system/doc/design_principles/fsm.xml +++ b/system/doc/design_principles/fsm.xml @@ -33,7 +33,7 @@ <note> <p> There is a new behaviour - <seealso marker="gen_statem"><c>gen_statem</c></seealso> + <seealso marker="statem"><c>gen_statem</c></seealso> that is intended to replace <c>gen_fsm</c> for new code. It has the same features and add some really useful. This module will not be removed for the foreseeable future |
