diff options
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 393 |
1 files changed, 154 insertions, 239 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index 6ad025d6c9..15c01c1006 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -632,8 +632,8 @@ enter(Module, Opts, State, Data, Server, Actions, Parent) -> postponed => P, %% %% The following fields are finally set from to the arguments to - %% loop_event_actions/11 when it finally loops back to loop/3 - %% in loop_events/10 + %% loop_event_actions/9 when it finally loops back to loop/3 + %% in loop_event_result/11 timer_refs => TimerRefs, timer_types => TimerTypes, hibernate => Hibernate, @@ -643,7 +643,7 @@ enter(Module, Opts, State, Data, Server, Actions, Parent) -> case call_callback_mode(S) of {ok,NewS} -> loop_event_actions( - Parent, NewDebug, NewS, TimerRefs, TimerTypes, CancelTimers, + Parent, NewDebug, NewS, Events, Event, State, Data, NewActions, true); {Class,Reason,Stacktrace} -> terminate( @@ -843,78 +843,66 @@ loop_hibernate(Parent, Debug, S) -> {wakeup_from_hibernate,3}}). %% Entry point for wakeup_from_hibernate/3 -loop_receive( - Parent, Debug, - #{timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers} = S) -> - loop_receive(Parent, Debug, S, TimerRefs, TimerTypes, CancelTimers). -%% -loop_receive( - Parent, Debug, - #{hibernate := Hibernate} = S, - TimerRefs, TimerTypes, CancelTimers) -> - %% The fields 'timer_refs', 'timer_types' and 'cancel_timers' - %% are now invalid in state map S - they will be recalculated - %% and restored when we return to loop/3 - %% +loop_receive(Parent, Debug, S) -> receive Msg -> case Msg of {system,Pid,Req} -> + #{hibernate := Hibernate} = S, %% Does not return but tail recursively calls %% system_continue/3 that jumps to loop/3 sys:handle_system_msg( - Req, Pid, Parent, ?MODULE, Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers}, + Req, Pid, Parent, ?MODULE, Debug, S, Hibernate); {'EXIT',Parent,Reason} = EXIT -> - %% 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, ?STACKTRACE(), Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers}, - [EXIT]); + %% EXIT is not a 2-tuple therefore + %% not an event but this will stand out + %% in the crash report... + Q = [EXIT], + terminate(exit, Reason, ?STACKTRACE(), Debug, S, Q); {timeout,TimerRef,TimerMsg} -> + #{timer_refs := TimerRefs, + timer_types := TimerTypes, + hibernate := Hibernate} = S, case TimerRefs of #{TimerRef := TimerType} -> - %% We know of this timer, is it a running - %% timer or a timer being cancelled but + %% We know of this timer; is it a running + %% timer or a timer being cancelled that %% managed to send a late timeout message? case TimerTypes of #{TimerType := TimerRef} -> - %% The timer type maps to this + %% The timer type maps back to this %% timer ref, so it was a running timer Event = {TimerType,TimerMsg}, %% Unregister the triggered timeout + NewTimerRefs = + maps:remove(TimerRef, TimerRefs), + NewTimerTypes = + maps:remove(TimerType, TimerTypes), loop_receive_result( - Parent, Debug, S, - maps:remove(TimerRef, TimerRefs), - maps:remove(TimerType, TimerTypes), - CancelTimers, Event); + Parent, Debug, + S#{ + timer_refs := NewTimerRefs, + timer_types := NewTimerTypes}, + Hibernate, + Event); _ -> %% This was a late timeout message %% from timer being cancelled, so - %% ignore it and expect a cancel - %% ack shortly - loop_receive( - Parent, Debug, S, - TimerRefs, TimerTypes, CancelTimers) + %% ignore it and expect a cancel_timer + %% msg shortly + loop_receive(Parent, Debug, S) end; _ -> + %% Not our timer; present it as an event Event = {info,Msg}, loop_receive_result( - Parent, Debug, S, - TimerRefs, TimerTypes, CancelTimers, Event) + Parent, Debug, S, Hibernate, Event) end; {cancel_timer,TimerRef,_} -> + #{timer_refs := TimerRefs, + cancel_timers := CancelTimers, + hibernate := Hibernate} = S, case TimerRefs of #{TimerRef := _} -> %% We must have requested a cancel @@ -922,36 +910,29 @@ loop_receive( %% removed from TimerTypes NewTimerRefs = maps:remove(TimerRef, TimerRefs), + NewCancelTimers = CancelTimers - 1, + NewS = + S#{ + timer_refs := NewTimerRefs, + cancel_timers := NewCancelTimers}, if - Hibernate =:= true, CancelTimers =:= 0 -> - loop_hibernate( - Parent, Debug, - S#{ - timer_refs := NewTimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers}); - CancelTimers > 0 -> - loop_receive( - Parent, Debug, S, - NewTimerRefs, TimerTypes, - CancelTimers - 1); - true -> - terminate( - error, impossible_message, - ?STACKTRACE(), Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers}, - [Msg]) + Hibernate =:= true, NewCancelTimers =:= 0 -> + %% No more cancel_timer msgs to expect; + %% we can hibernate + loop_hibernate(Parent, Debug, NewS); + NewCancelTimers >= 0 -> % Assert + loop_receive(Parent, Debug, NewS) end; _ -> + %% Not our cancel_timer msg; + %% present it as an event Event = {info,Msg}, loop_receive_result( - Parent, Debug, S, - TimerRefs, TimerTypes, CancelTimers, Event) + Parent, Debug, S, Hibernate, Event) end; _ -> + %% External msg + #{hibernate := Hibernate} = S, Event = case Msg of {'$gen_call',From,Request} -> @@ -962,116 +943,105 @@ loop_receive( {info,Msg} end, loop_receive_result( - Parent, Debug, S, - TimerRefs, TimerTypes, CancelTimers, Event) + Parent, Debug, S, Hibernate, Event) end end. loop_receive_result( - Parent, Debug, #{state := State} = S, - TimerRefs, TimerTypes, CancelTimers, Event) -> - %% The field 'hibernate' is now invalid in state map S - %% - it will be recalculated and restored when we return to loop/3 - %% + Parent, Debug, #{state := State} = S, Hibernate, Event) -> + %% From now the 'hibernate' field in S is invalid + %% and will be restored when looping back + %% in loop_event_result/11 NewDebug = sys_debug(Debug, S, State, {in,Event}), - %% Here the queue of not yet handled events is created + %% Here is the queue of not yet handled events created Events = [], - Hibernate = false, - loop_event( - Parent, NewDebug, S, TimerRefs, TimerTypes, CancelTimers, - Events, Event, Hibernate). + loop_event(Parent, NewDebug, S, Events, Event, Hibernate). %% Entry point for handling an event, received or enqueued loop_event( - Parent, Debug, #{state := State, data := Data} = S, - TimerRefs, TimerTypes, CancelTimers, + Parent, Debug, + #{state := State, data := Data, timer_types := TimerTypes, + cancel_timers := CancelTimers} = S_0, Events, {Type,Content} = Event, Hibernate) -> %% - %% If Hibernate is true here it can only be + %% If (this old) 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 + %% and we did not go into hibernation since there were + %% events in queue, so we do what the user %% might rely on i.e collect garbage which %% would have happened if we actually hibernated %% and immediately was awakened Hibernate andalso garbage_collect(), - %% So now the old Hibernate is dead, and a new one emerges - %% within loop_event_actions - case call_state_function(S, Type, Content, State, Data) of - {ok,Result,NewS} -> + case call_state_function(S_0, Type, Content, State, Data) of + {ok,Result,S_1} -> %% Cancel event timeout - {NewTimerTypes,NewCancelTimers} = - cancel_timer_by_type(timeout, TimerTypes, CancelTimers), - %% The timer is removed from NewTimerTypes but - %% remains in TimerRefs until we get the cancel_timers msg - {NewData,NextState,Actions,EnterCall} = + S_2 = + case + cancel_timer_by_type(timeout, TimerTypes, CancelTimers) + of + {_,CancelTimers} -> + %% No timer cancelled + S_1; + {NewTimerTypes,NewCancelTimers} -> + %% The timer is removed from NewTimerTypes but + %% remains in TimerRefs until we get + %% the cancel_timer msg + S_1#{ + timer_types := NewTimerTypes, + cancel_timers := NewCancelTimers} + end, + {NextState,NewData,Actions,EnterCall} = parse_event_result( - true, Debug, NewS, - TimerRefs, NewTimerTypes, NewCancelTimers, - Events, Event, State, Data, false, Result), + true, Debug, S_2, + Events, Event, State, Data, Result), loop_event_actions( - Parent, Debug, NewS, - TimerRefs, NewTimerTypes, NewCancelTimers, + Parent, Debug, S_2, Events, Event, NextState, NewData, Actions, EnterCall); {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, + Class, Reason, Stacktrace, Debug, S_0, [Event|Events]) end. loop_event_actions( Parent, Debug, #{state := State, state_enter := StateEnter} = S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, Actions, EnterCall) -> + %% Hibernate is reborn here as false being + %% the default value from parse_actions/4 case parse_actions(Debug, S, State, Actions) of {ok,NewDebug,Hibernate,TimeoutsR,Postpone,NextEventsR} -> if StateEnter, EnterCall -> loop_event_enter( Parent, NewDebug, S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, Hibernate, TimeoutsR, Postpone, NextEventsR); true -> loop_event_result( Parent, NewDebug, S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, Hibernate, TimeoutsR, Postpone, NextEventsR) end; {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, Debug, - S#{ - data := NewData, - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := false}, + Class, Reason, Stacktrace, Debug, S, [Event|Events]) end. loop_event_enter( Parent, Debug, #{state := State} = S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, Hibernate, TimeoutsR, Postpone, NextEventsR) -> case call_state_function(S, enter, State, NextState, NewData) of {ok,Result,NewS} -> case parse_event_result( - false, Debug, NewS, TimerRefs, TimerTypes, CancelTimers, - Events, Event, NextState, NewData, Hibernate, Result) of - {NewerData,_,Actions,EnterCall} -> + false, Debug, NewS, + Events, Event, NextState, NewData, Result) of + {_,NewerData,Actions,EnterCall} -> loop_event_enter_actions( Parent, Debug, NewS, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewerData, Hibernate, TimeoutsR, Postpone, NextEventsR, Actions, EnterCall) @@ -1082,16 +1052,12 @@ loop_event_enter( S#{ state := NextState, data := NewData, - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, hibernate := Hibernate}, [Event|Events]) end. loop_event_enter_actions( Parent, Debug, #{state_enter := StateEnter} = S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, Hibernate, TimeoutsR, Postpone, NextEventsR, Actions, EnterCall) -> @@ -1104,13 +1070,11 @@ loop_event_enter_actions( StateEnter, EnterCall -> loop_event_enter( Parent, NewDebug, S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, NewHibernate, NewTimeoutsR, Postpone, NextEventsR); true -> loop_event_result( Parent, NewDebug, S, - TimerRefs, TimerTypes, CancelTimers, Events, Event, NextState, NewData, NewHibernate, NewTimeoutsR, Postpone, NextEventsR) end; @@ -1120,89 +1084,71 @@ loop_event_enter_actions( S#{ state := NextState, data := NewData, - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, hibernate := Hibernate}, [Event|Events]) end. loop_event_result( - Parent, Debug, - #{state := State, postponed := P_0} = S, - TimerRefs_0, TimerTypes_0, CancelTimers_0, - Events, Event, NextState, NewData, + Parent, Debug_0, + #{state := State, postponed := P_0, + timer_refs := TimerRefs_0, timer_types := TimerTypes_0, + cancel_timers := CancelTimers_0} = S_0, + Events_0, Event_0, NextState, NewData, Hibernate, TimeoutsR, Postpone, NextEventsR) -> %% %% All options have been collected and next_events are buffered. %% Do the actual state transition. %% - {NewDebug,P_1} = % Move current event to postponed if Postpone + {Debug_1,P_1} = % Move current event to postponed if Postpone case Postpone of true -> - {sys_debug(Debug, S, State, {postpone,Event,State}), - [Event|P_0]}; + {sys_debug(Debug_0, S_0, State, {postpone,Event_0,State}), + [Event_0|P_0]}; false -> - {sys_debug(Debug, S, State, {consume,Event,State}), + {sys_debug(Debug_0, S_0, State, {consume,Event_0,State}), P_0} end, - {Events_1,NewP,{TimerTypes_1,CancelTimers_1}} = + {Events_1,P_2,{TimerTypes_1,CancelTimers_1}} = %% Move all postponed events to queue and cancel the %% state timeout if the state changes if NextState =:= State -> - {Events,P_1,{TimerTypes_0,CancelTimers_0}}; + {Events_0,P_1,{TimerTypes_0,CancelTimers_0}}; true -> - {lists:reverse(P_1, Events),[], + {lists:reverse(P_1, Events_0), + [], cancel_timer_by_type( state_timeout, TimerTypes_0, CancelTimers_0)} %% The state timer is removed from TimerTypes_1 %% but remains in TimerRefs_0 until we get %% the cancel_timer msg end, - {TimerRefs_2,TimerTypes_2,NewCancelTimers,TimeoutEvents} = - %% Stop and start timers non-event timers + {TimerRefs_2,TimerTypes_2,CancelTimers_2,TimeoutEvents} = + %% Stop and start non-event timers parse_timers(TimerRefs_0, TimerTypes_1, CancelTimers_1, TimeoutsR), %% Place next events last in reversed queue Events_2R = lists:reverse(Events_1, NextEventsR), %% Enqueue immediate timeout events and start event timer - {NewTimerRefs,NewTimerTypes,Events_3R} = + {TimerRefs_3,TimerTypes_3,Events_3R} = process_timeout_events( TimerRefs_2, TimerTypes_2, TimeoutEvents, Events_2R), - NewEvents = lists:reverse(Events_3R), - loop_events( - Parent, NewDebug, S, NewTimerRefs, NewTimerTypes, NewCancelTimers, - NewEvents, Hibernate, NextState, NewData, NewP). - -%% Loop until out of enqueued events -%% -loop_events( - Parent, Debug, S, TimerRefs, TimerTypes, CancelTimers, - [] = _Events, Hibernate, State, Data, P) -> - %% Update S and loop back to loop/3 to receive a new event - NewS = - S#{ - state := State, - data := Data, - postponed := P, - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, + S_1 = + S_0#{ + state := NextState, + data := NewData, + postponed := P_2, + timer_refs := TimerRefs_3, + timer_types := TimerTypes_3, + cancel_timers := CancelTimers_2, hibernate := Hibernate}, - loop(Parent, Debug, NewS); -loop_events( - Parent, Debug, S, TimerRefs, TimerTypes, CancelTimers, - [Event|Events], Hibernate, State, Data, P) -> - %% Update S and continue with enqueued events - NewS = - S#{ - state := State, - data := Data, - postponed := P}, - loop_event( - Parent, Debug, NewS, TimerRefs, TimerTypes, CancelTimers, - Events, Event, Hibernate). - + case lists:reverse(Events_3R) of + [] -> + %% Get a new event + loop(Parent, Debug_1, S_1); + [Event|Events] -> + %% Loop until out of enqueued events + loop_event(Parent, Debug_1, S_1, Events, Event, Hibernate) + end. %%--------------------------------------------------------------------------- @@ -1272,8 +1218,7 @@ parse_callback_mode(_, _CBMode, StateEnter) -> call_state_function( - #{callback_mode := undefined} = S, - Type, Content, State, Data) -> + #{callback_mode := undefined} = S, Type, Content, State, Data) -> case call_callback_mode(S) of {ok,NewS} -> call_state_function(NewS, Type, Content, State, Data); @@ -1281,8 +1226,7 @@ call_state_function( Error end; call_state_function( - #{callback_mode := CallbackMode, - module := Module} = S, + #{callback_mode := CallbackMode, module := Module} = S, Type, Content, State, Data) -> try case CallbackMode of @@ -1339,105 +1283,74 @@ call_state_function( %% Interpret all callback return variants parse_event_result( - AllowStateChange, Debug, S, TimerRefs, TimerTypes, CancelTimers, - Events, Event, State, Data, Hibernate, Result) -> + AllowStateChange, Debug, S, + Events, Event, State, Data, Result) -> case Result of stop -> terminate( exit, normal, ?STACKTRACE(), Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, + S#{state := State, data := Data}, [Event|Events]); {stop,Reason} -> terminate( exit, Reason, ?STACKTRACE(), Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, + S#{state := State, data := Data}, [Event|Events]); {stop,Reason,NewData} -> terminate( exit, Reason, ?STACKTRACE(), Debug, - S#{ - data := NewData, - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, + S#{state := State, data := NewData}, [Event|Events]); %% {stop_and_reply,Reason,Replies} -> - Q = [Event|Events], reply_then_terminate( exit, Reason, ?STACKTRACE(), Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, - Q, Replies); + S#{state := State, data := Data}, + [Event|Events], Replies); {stop_and_reply,Reason,Replies,NewData} -> - Q = [Event|Events], reply_then_terminate( exit, Reason, ?STACKTRACE(), Debug, - S#{ - data := NewData, - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, - Q, Replies); + S#{state := State, data := NewData}, + [Event|Events], Replies); %% {next_state,State,NewData} -> - {NewData,State,[],false}; + {State,NewData,[],false}; {next_state,NextState,NewData} when AllowStateChange -> - {NewData,NextState,[],true}; + {NextState,NewData,[],true}; {next_state,State,NewData,Actions} -> - {NewData,State,Actions,false}; + {State,NewData,Actions,false}; {next_state,NextState,NewData,Actions} when AllowStateChange -> - {NewData,NextState,Actions,true}; + {NextState,NewData,Actions,true}; %% {keep_state,NewData} -> - {NewData,State,[],false}; + {State,NewData,[],false}; {keep_state,NewData,Actions} -> - {NewData,State,Actions,false}; + {State,NewData,Actions,false}; keep_state_and_data -> - {Data,State,[],false}; + {State,Data,[],false}; {keep_state_and_data,Actions} -> - {Data,State,Actions,false}; + {State,Data,Actions,false}; %% {repeat_state,NewData} -> - {NewData,State,[],true}; + {State,NewData,[],true}; {repeat_state,NewData,Actions} -> - {NewData,State,Actions,true}; + {State,NewData,Actions,true}; repeat_state_and_data -> - {Data,State,[],true}; + {State,Data,[],true}; {repeat_state_and_data,Actions} -> - {Data,State,Actions,true}; + {State,Data,Actions,true}; %% _ -> terminate( error, {bad_return_from_state_function,Result}, - ?STACKTRACE(), - Debug, - S#{ - timer_refs := TimerRefs, - timer_types := TimerTypes, - cancel_timers := CancelTimers, - hibernate := Hibernate}, + ?STACKTRACE(), Debug, + S#{state := State, data := Data}, [Event|Events]) end. -parse_enter_actions( - Debug, S, State, Actions, - Hibernate, TimeoutsR) -> +parse_enter_actions(Debug, S, State, Actions, Hibernate, TimeoutsR) -> Postpone = forbidden, NextEventsR = forbidden, parse_actions( @@ -1484,9 +1397,10 @@ parse_actions( {bad_action_from_state_function,Action}, ?STACKTRACE()}; hibernate -> + NewHibernate = true, parse_actions( Debug, S, State, Actions, - true, TimeoutsR, Postpone, NextEventsR); + NewHibernate, TimeoutsR, Postpone, NextEventsR); {state_timeout,Time,_} = StateTimeout when is_integer(Time), Time >= 0; Time =:= infinity -> @@ -1529,9 +1443,10 @@ parse_actions( {bad_action_from_state_function,Action}, ?STACKTRACE()}; postpone when Postpone =/= forbidden -> + NewPostpone = true, parse_actions( Debug, S, State, Actions, - Hibernate, TimeoutsR, true, NextEventsR); + Hibernate, TimeoutsR, NewPostpone, NextEventsR); {next_event,Type,Content} -> case event_type(Type) of true when NextEventsR =/= forbidden -> |