diff options
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 309 |
1 files changed, 176 insertions, 133 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index f9e2e5f7d2..36476b56ae 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') %% @@ -523,12 +523,15 @@ 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 +543,17 @@ 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, {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 @@ -681,13 +686,13 @@ print_event(Dev, {out,Reply,{To,_Tag}}, #{name := 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 := Name, state := 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", @@ -697,8 +702,8 @@ 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) -> @@ -754,7 +759,8 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) -> %% but this will stand out in the crash report... ?TERMINATE(exit, Reason, Debug, S, [EXIT]); {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 +788,81 @@ 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 +loop_receive_result( + Parent, Debug, + #{state := State, + data := Data, + postponed := P} = S, + Event) -> + %% The S map is now dismantled and will not be restored + %% until we return to loop/3 or have to terminate. + %% + %% 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, {in,Event}), - %% Here the queue of not yet processed events is created - loop_events(Parent, NewDebug, S, [Event], false). + %% 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 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); +%% 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 +870,7 @@ 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 +880,11 @@ 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 +893,9 @@ loop_events( error, {undef_state_function,{Module,State,Args}}, Stacktrace, - Debug, S, Q); + Debug, S, [Event|Events]); Stacktrace -> - terminate(error, badarg, Stacktrace, Debug, S, Q) + terminate(error, badarg, Stacktrace, Debug, S, [Event|Events]) end; error:undef -> %% Process an undef to check for the simple mistake @@ -852,7 +910,7 @@ loop_events( error, {undef_state_function,{Module,State,Args}}, Stacktrace, - Debug, S, Q); + Debug, S, [Event|Events]); [{Module,handle_event, [Type,Content,State,Data]=Args, _} @@ -863,40 +921,42 @@ loop_events( {undef_state_function, {Module,handle_event,Args}}, Stacktrace, - Debug, S, Q); + Debug, S, [Event|Events]); Stacktrace -> - terminate(error, undef, Stacktrace, Debug, S, Q) + terminate( + error, undef, Stacktrace, Debug, S, [Event|Events]) end; Class:Reason -> Stacktrace = erlang:get_stacktrace(), - terminate(Class, Reason, Stacktrace, Debug, S, Q) + terminate(Class, Reason, Stacktrace, Debug, S, [Event|Events]) 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]); + NewS = S#{state := State, data := Data, postponed := P}, + Q = [Event|Events], + ?TERMINATE(exit, normal, Debug, NewS, Q); {stop,Reason} -> - ?TERMINATE(exit, Reason, Debug, S, [Event|Events]); + NewS = S#{state := State, data := Data, postponed := P}, + Q = [Event|Events], + ?TERMINATE(exit, Reason, Debug, NewS, Q); {stop,Reason,NewData} -> - NewS = S#{data := NewData}, + NewS = S#{state := State, data := NewData, postponed := P}, Q = [Event|Events], ?TERMINATE(exit, Reason, Debug, NewS, Q); {stop_and_reply,Reason,Replies} -> + NewS = S#{state := State, data := Data, postponed := P}, Q = [Event|Events], [Class,NewReason,Stacktrace,NewDebug] = reply_then_terminate( - exit, Reason, ?STACKTRACE(), Debug, S, Q, Replies), + exit, Reason, ?STACKTRACE(), Debug, NewS, Q, Replies), %% Since we got back here Replies was bad - terminate(Class, NewReason, Stacktrace, NewDebug, S, Q); + terminate(Class, NewReason, Stacktrace, NewDebug, NewS, Q); {stop_and_reply,Reason,Replies,NewData} -> - NewS = S#{data := NewData}, + NewS = S#{state := State, data := NewData, postponed := P}, Q = [Event|Events], [Class,NewReason,Stacktrace,NewDebug] = reply_then_terminate( @@ -905,41 +965,43 @@ loop_event_result( terminate(Class, NewReason, Stacktrace, NewDebug, NewS, Q); {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); _ -> + NewS = S#{state := State, data := Data, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_return_value,Result}, Debug, S, [Event|Events]) + error, {bad_return_value,Result}, Debug, NewS, Q) 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; @@ -948,10 +1010,10 @@ 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 @@ -960,85 +1022,99 @@ loop_event_actions( true -> NewDebug = do_reply(Debug, S, 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 -> + NewS = + S#{state := State, data := NewData, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]) + error, {bad_action,Action}, Debug, NewS, Q) 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 -> + NewS = + S#{state := State, data := NewData, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]) + error, {bad_action,Action}, Debug, NewS, Q) 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,_} -> + NewS = S#{state := State, data := NewData, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]); + error, {bad_action,Action}, Debug, NewS, Q); 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,_} -> + NewS = S#{state := State, data := NewData, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]); + error, {bad_action,Action}, Debug, NewS, Q); 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,_,_} -> + NewS = S#{state := State, data := NewData, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]); + error, {bad_action,Action}, Debug, NewS, Q); 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); _ -> + NewS = S#{state := State, data := NewData, postponed := P}, + Q = [Event|Events], ?TERMINATE( - error, {bad_action,Action}, Debug, S, [Event|Events]) + error, {bad_action,Action}, Debug, NewS, Q) 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. @@ -1059,7 +1135,7 @@ 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( @@ -1070,41 +1146,8 @@ loop_event_actions( 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 |