diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 66 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 602 | ||||
| -rw-r--r-- | lib/stdlib/test/gen_statem_SUITE.erl | 30 |
3 files changed, 364 insertions, 334 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index fb1e4e8da2..567130875a 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -639,6 +639,20 @@ handle_event(_, _, State, Data) -> </p> <list type="ordered"> <item> + <p> + If the state changes or is the initial state, and + <seealso marker="#type-state_enter"><em>state enter calls</em></seealso> + are used, the <c>gen_statem</c> calls + the new state callback with arguments + <seealso marker="#type-state_enter">(enter, OldState, Data)</seealso>. + Any + <seealso marker="#type-enter_action"><c>actions</c></seealso> + returned from this call are handled as if they were + appended to the actions + returned by the state callback that changed states. + </p> + </item> + <item> <p> All <seealso marker="#type-action">actions</seealso> @@ -668,36 +682,36 @@ handle_event(_, _, State, Data) -> </p> </item> <item> - <p> - If the state changes or is the initial state, and - <seealso marker="#type-state_enter"><em>state enter calls</em></seealso> - are used, the <c>gen_statem</c> calls - the new state callback with arguments - <seealso marker="#type-state_enter">(enter, OldState, Data)</seealso>. - Any - <seealso marker="#type-enter_action"><c>actions</c></seealso> - returned from this call are handled as if they were - appended to the actions - returned by the state callback that changed states. - </p> - </item> - <item> - <p> - If there are enqueued events the (possibly new) - <seealso marker="#state callback">state callback</seealso> - is called with the oldest enqueued event, - and we start again from the top of this list. - </p> - </item> - <item> <p> Timeout timers <seealso marker="#type-state_timeout"><c>state_timeout()</c></seealso> and <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso> - are handled. This may lead to a time-out zero event - being generated to the + are handled. Time-outs with zero time are guaranteed to be + delivered to the state machine before any external + not yet received event so if there is such a timeout requested, + the corresponding time-out zero event is enqueued as + the newest event. + </p> + <p> + Any event cancels an + <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso> + so a zero time event time-out is only generated + if the event queue is empty. + </p> + <p> + A state change cancels a + <seealso marker="#type-state_timeout"><c>state_timeout()</c></seealso> + and any new transition option of this type + belongs to the new state. + </p> + </item> + <item> + <p> + If there are enqueued events the <seealso marker="#state callback">state callback</seealso> + for the possibly new state + is called with the oldest enqueued event, and we start again from the top of this list. </p> </item> @@ -802,7 +816,7 @@ handle_event(_, _, State, Data) -> <p> Setting this timer while it is running will restart it with the new time-out value. Therefore it is possible to cancel - this timeout by setting it to <c>infinity</c>. + this time-out by setting it to <c>infinity</c>. </p> </desc> </datatype> @@ -1130,7 +1144,7 @@ handle_event(_, _, State, Data) -> <c><anno>Timeout</anno></c> can also be a tuple <c>{clean_timeout,<anno>T</anno>}</c> or <c>{dirty_timeout,<anno>T</anno>}</c>, where - <c><anno>T</anno></c> is the timeout time. + <c><anno>T</anno></c> is the time-out time. <c>{clean_timeout,<anno>T</anno>}</c> works like just <c>T</c> described in the note above and uses a proxy process for <c>T < infinity</c>, diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index a314f43b42..c81916197c 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -85,7 +85,8 @@ -type state_enter() :: 'state_enter'. -type transition_option() :: - postpone() | hibernate() | event_timeout(). + postpone() | hibernate() | + event_timeout() | state_timeout(). -type postpone() :: %% If 'true' postpone the current event %% and retry it when the state changes (=/=) @@ -108,7 +109,7 @@ %% * All action()s are executed in order of apperance. %% * Postponing the current event is performed %% iff 'postpone' is 'true'. - %% * A state timer is started iff 'timeout' is set. + %% * A state timeout is started iff 'timeout' is set. %% * Pending events are handled or if there are %% no pending events the server goes into receive %% or hibernate (iff 'hibernate' is 'true') @@ -596,8 +597,8 @@ enter(Module, Opts, State, Data, Server, Actions, Parent) -> data => Data, postponed => P, %% The rest of the fields are set from to the arguments to - %% loop_event_actions/9 when it finally loops back to loop/3 - %% in loop_events_done/9 + %% loop_event_actions/10 when it finally loops back to loop/3 + %% in loop_events/10 %% %% Marker for initial state, cleared immediately when used init_state => true @@ -605,9 +606,10 @@ enter(Module, Opts, State, Data, Server, Actions, Parent) -> NewDebug = sys_debug(Debug, S, State, {enter,Event,State}), case call_callback_mode(S) of {ok,NewS} -> - StateTimer = undefined, + TimerRefs = #{}, + TimerTypes = #{}, loop_event_actions( - Parent, NewDebug, NewS, StateTimer, + Parent, NewDebug, NewS, TimerRefs, TimerTypes, Events, Event, State, Data, NewActions); {Class,Reason,Stacktrace} -> terminate( @@ -806,7 +808,7 @@ loop(Parent, Debug, #{hibernate := Hibernate} = S) -> %% Entry point for wakeup_from_hibernate/3 loop_receive( - Parent, Debug, #{timer := Timer, state_timer := StateTimer} = S) -> + Parent, Debug, #{timer_refs := TimerRefs, timer_types := TimerTypes} = S) -> receive Msg -> case Msg of @@ -822,18 +824,23 @@ loop_receive( %% but this will stand out in the crash report... terminate( exit, Reason, ?STACKTRACE(), Debug, S, [EXIT]); - {timeout,Timer,Content} - when Timer =/= undefined -> - loop_receive_result( - Parent, Debug, S, StateTimer, - {timeout,Content}); - {timeout,StateTimer,Content} - when StateTimer =/= undefined -> - loop_receive_result( - Parent, Debug, S, undefined, - {state_timeout,Content}); + {timeout,TimerRef,TimerMsg} -> + case TimerRefs of + #{TimerRef := TimerType} -> + Event = {TimerType,TimerMsg}, + %% Unregister the triggered timeout + loop_receive_result( + Parent, Debug, S, + maps:remove(TimerRef, TimerRefs), + maps:remove(TimerType, TimerTypes), + Event); + _ -> + Event = {info,Msg}, + loop_receive_result( + Parent, Debug, S, + TimerRefs, TimerTypes, Event) + end; _ -> - cancel_timer(Timer), Event = case Msg of {'$gen_call',From,Request} -> @@ -844,12 +851,15 @@ loop_receive( {info,Msg} end, loop_receive_result( - Parent, Debug, S, StateTimer, Event) + Parent, Debug, S, + TimerRefs, TimerTypes, Event) end end. -loop_receive_result(Parent, Debug, #{state := State} = S, StateTimer, Event) -> - %% The fields 'timer', 'state_timer' and 'hibernate' +loop_receive_result( + Parent, Debug, #{state := State} = S, + TimerRefs, TimerTypes, Event) -> + %% The fields 'timer_refs', 'timer_types' and 'hibernate' %% are now invalid in state map S - they will be recalculated %% and restored when we return to loop/3 %% @@ -857,82 +867,197 @@ loop_receive_result(Parent, Debug, #{state := State} = S, StateTimer, Event) -> %% Here the queue of not yet handled events is created Events = [], Hibernate = false, - loop_event(Parent, NewDebug, S, StateTimer, Events, Event, Hibernate). + loop_event( + Parent, NewDebug, S, TimerRefs, TimerTypes, Events, 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, StateTimeout, - [Event|Events], _Timeout, State, Data, P, Hibernate) -> +%% Entry point for handling an event, received or enqueued +loop_event( + Parent, Debug, #{state := State, data := Data} = S, TimerRefs, TimerTypes, + Events, {Type,Content} = Event, Hibernate) -> %% - %% If there was an event timer requested we just ignore that - %% since we have events to handle which cancels the timer - loop_event( - Parent, Debug, S, StateTimeout, - Events, Event, State, Data, P, Hibernate); -loop_events( - Parent, Debug, S, {state_timeout,Time,EventContent}, - [] = Events, Timeout, State, Data, P, Hibernate) -> - if - Time =:= 0 -> - %% Simulate an immediate timeout - %% so we do not get the timeout message - %% after any received event - %% - %% This faked event will cancel - %& any not yet started event timer - Event = {state_timeout,EventContent}, - StateTimer = undefined, - loop_event( - Parent, Debug, S, StateTimer, - Events, Event, State, Data, P, Hibernate); - true -> - StateTimer = erlang:start_timer(Time, self(), EventContent), - loop_events( - Parent, Debug, S, StateTimer, - Events, Timeout, State, Data, P, Hibernate) - end; -loop_events( - Parent, Debug, S, StateTimer, - [] = Events, Timeout, State, Data, P, Hibernate) -> - case Timeout of - {timeout,0,EventContent} -> - %% Simulate an immediate timeout - %% so we do not get the timeout message - %% after any received event - %% - Event = {timeout,EventContent}, - loop_event( - Parent, Debug, S, StateTimer, - Events, Event, State, Data, P, Hibernate); - {timeout,Time,EventContent} -> - Timer = erlang:start_timer(Time, self(), EventContent), - loop_events_done( - Parent, Debug, S, StateTimer, - State, Data, P, Hibernate, Timer); - undefined -> - %% No event timeout has been requested - Timer = undefined, - loop_events_done( - Parent, Debug, S, StateTimer, - State, Data, P, Hibernate, Timer) + %% 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 + %% might rely on i.e collect garbage which + %% would have happened if we actually hibernated + %% and immediately was awakened + Hibernate andalso garbage_collect(), + case call_state_function(S, Type, Content, State, Data) of + {ok,Result,NewS} -> + %% Cancel event timeout + {NewTimerRefs,NewTimerTypes} = + cancel_timer_by_type( + timeout, TimerRefs, TimerTypes), + {NewData,NextState,Actions} = + parse_event_result( + true, Debug, NewS, Result, + Events, Event, State, Data), + loop_event_actions( + Parent, Debug, S, NewTimerRefs, NewTimerTypes, + Events, Event, NextState, NewData, Actions); + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, Debug, S, [Event|Events]) + end. + +loop_event_actions( + Parent, Debug, + #{state := State, state_enter := StateEnter} = S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, Actions) -> + case parse_actions(Debug, S, State, Actions) of + {ok,NewDebug,Hibernate,TimeoutsR,Postpone,NextEventsR} -> + if + StateEnter, NextState =/= State -> + loop_event_enter( + Parent, NewDebug, S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR); + StateEnter -> + case maps:is_key(init_state, S) of + true -> + %% Avoid infinite loop in initial state + %% with state entry events + NewS = maps:remove(init_state, S), + loop_event_enter( + Parent, NewDebug, NewS, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR); + false -> + loop_event_result( + Parent, NewDebug, S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR) + end; + true -> + loop_event_result( + Parent, NewDebug, S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR) + end; + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, + Debug, S#{data := NewData}, [Event|Events]) + end. + +loop_event_enter( + Parent, Debug, #{state := State} = S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR) -> + case call_state_function(S, enter, State, NextState, NewData) of + {ok,Result,NewS} -> + {NewerData,_,Actions} = + parse_event_result( + false, Debug, NewS, Result, + Events, Event, NextState, NewData), + loop_event_enter_actions( + Parent, Debug, NewS, TimerRefs, TimerTypes, + Events, Event, NextState, NewerData, + Hibernate, TimeoutsR, Postpone, NextEventsR, Actions); + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, + Debug, S#{state := NextState, data := NewData}, + [Event|Events]) + end. + +loop_event_enter_actions( + Parent, Debug, S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR, Actions) -> + case + parse_enter_actions( + Debug, S, NextState, Actions, + Hibernate, TimeoutsR) + of + {ok,NewDebug,NewHibernate,NewTimeoutsR,_,_} -> + loop_event_result( + Parent, NewDebug, S, TimerRefs, TimerTypes, + Events, Event, NextState, NewData, + NewHibernate, NewTimeoutsR, Postpone, NextEventsR); + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, + Debug, S#{state := NextState, data := NewData}, + [Event|Events]) end. -%% Back to the top -loop_events_done( - Parent, Debug, S, StateTimer, - State, Data, P, Hibernate, Timer) -> +loop_event_result( + Parent, Debug, + #{state := State, postponed := P_0} = S, TimerRefs_0, TimerTypes_0, + Events, Event, 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 + case Postpone of + true -> + {sys_debug(Debug, S, State, {postpone,Event,State}), + [Event|P_0]}; + false -> + {sys_debug(Debug, S, State, {consume,Event,State}), + P_0} + end, + {Events_1,NewP,{TimerRefs,TimerTypes}} = + %% Move all postponed events to queue and cancel the + %% state timeout if the state changes + if + NextState =:= State -> + {Events,P_1,{TimerRefs_0,TimerTypes_0}}; + true -> + {lists:reverse(P_1, Events),[], + cancel_timer_by_type( + state_timeout, TimerRefs_0, TimerTypes_0)} + end, + {NewTimerRefs,NewTimerTypes,TimeoutEvents} = + %% Stop and start timers + handle_timers(TimerRefs, TimerTypes, TimeoutsR), + %% Place next events first in reversed queue + NewEventsR = lists:reverse(Events_1, NextEventsR), + %% Append timeout zero events + NewEvents = + lists:reverse( + NewEventsR, + process_timeout_events(TimeoutEvents, NewEventsR)), + %% + loop_events( + Parent, NewDebug, S, NewTimerRefs, NewTimerTypes, + NewEvents, Hibernate, NextState, NewData, NewP). + +%% Loop until out of enqueued events +%% +loop_events( + Parent, Debug, S, TimerRefs, TimerTypes, + [] = _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, hibernate => Hibernate, - timer => Timer, - state_timer => StateTimer}, - loop(Parent, Debug, NewS). + timer_refs => TimerRefs, + timer_types => TimerTypes}, + loop(Parent, Debug, NewS); +loop_events( + Parent, Debug, S, TimerRefs, TimerTypes, + [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, Events, Event, Hibernate). + +%%--------------------------------------------------------------------------- +%% Server loop helpers call_callback_mode(#{module := Module} = S) -> try Module:callback_mode() of @@ -996,6 +1121,7 @@ parse_callback_mode([H|T], CBMode, StateEnter) -> parse_callback_mode(_, _CBMode, StateEnter) -> {undefined,StateEnter}. + call_state_function( #{callback_mode := undefined} = S, Type, Content, State, Data) -> @@ -1061,42 +1187,6 @@ call_state_function( {Class,Reason,erlang:get_stacktrace()} end. -%% Update S and continue -loop_event( - Parent, Debug, S, StateTimer, - Events, Event, State, Data, P, Hibernate) -> - NewS = - S#{ - state := State, - data := Data, - postponed := P}, - loop_event(Parent, Debug, NewS, StateTimer, Events, Event, Hibernate). - -loop_event( - Parent, Debug, #{state := State, data := Data} = S, StateTimer, - Events, {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 - %% might rely on i.e collect garbage which - %% would have happened if we actually hibernated - %% and immediately was awakened - Hibernate andalso garbage_collect(), - case call_state_function(S, Type, Content, State, Data) of - {ok,Result,NewS} -> - {NewData,NextState,Actions} = - parse_event_result( - true, Debug, NewS, Result, - Events, Event, State, Data), - loop_event_actions( - Parent, Debug, S, StateTimer, - Events, Event, NextState, NewData, Actions); - {Class,Reason,Stacktrace} -> - terminate( - Class, Reason, Stacktrace, Debug, S, [Event|Events]) - end. %% Interpret all callback return variants parse_event_result( @@ -1146,32 +1236,32 @@ parse_event_result( Debug, S, [Event|Events]) end. + parse_enter_actions( Debug, S, State, Actions, - Hibernate, Timeout, StateTimeout) -> + Hibernate, TimeoutsR) -> Postpone = forbidden, - NextEvents = forbidden, + NextEventsR = forbidden, parse_actions( Debug, S, State, listify(Actions), - Hibernate, Timeout, StateTimeout, Postpone, NextEvents). + Hibernate, TimeoutsR, Postpone, NextEventsR). parse_actions(Debug, S, State, Actions) -> Hibernate = false, - Timeout = undefined, - StateTimeout = undefined, + TimeoutsR = [], Postpone = false, - NextEvents = [], + NextEventsR = [], parse_actions( Debug, S, State, listify(Actions), - Hibernate, Timeout, StateTimeout, Postpone, NextEvents). + Hibernate, TimeoutsR, Postpone, NextEventsR). %% parse_actions( Debug, _S, _State, [], - Hibernate, Timeout, StateTimeout, Postpone, NextEvents) -> - {ok,Debug,Hibernate,Timeout,StateTimeout,Postpone,NextEvents}; + Hibernate, TimeoutsR, Postpone, NextEventsR) -> + {ok,Debug,Hibernate,TimeoutsR,Postpone,NextEventsR}; parse_actions( Debug, S, State, [Action|Actions], - Hibernate, Timeout, StateTimeout, Postpone, NextEvents) -> + Hibernate, TimeoutsR, Postpone, NextEventsR) -> case Action of %% Actual actions {reply,From,Reply} -> @@ -1180,8 +1270,7 @@ parse_actions( NewDebug = do_reply(Debug, S, State, From, Reply), parse_actions( NewDebug, S, State, Actions, - Hibernate, Timeout, StateTimeout, - Postpone, NextEvents); + Hibernate, TimeoutsR, Postpone, NextEventsR); false -> {error, {bad_action_from_state_function,Action}, @@ -1191,7 +1280,7 @@ parse_actions( {hibernate,NewHibernate} when is_boolean(NewHibernate) -> parse_actions( Debug, S, State, Actions, - NewHibernate, Timeout, StateTimeout, Postpone, NextEvents); + NewHibernate, TimeoutsR, Postpone, NextEventsR); {hibernate,_} -> {error, {bad_action_from_state_function,Action}, @@ -1199,43 +1288,44 @@ parse_actions( hibernate -> parse_actions( Debug, S, State, Actions, - true, Timeout, StateTimeout, Postpone, NextEvents); - {state_timeout,Time,_} = NewStateTimeout + true, TimeoutsR, Postpone, NextEventsR); + {state_timeout,Time,_} = StateTimeout when is_integer(Time), Time >= 0; Time =:= infinity -> parse_actions( Debug, S, State, Actions, - Hibernate, Timeout, NewStateTimeout, Postpone, NextEvents); + Hibernate, [StateTimeout|TimeoutsR], Postpone, NextEventsR); {state_timeout,_,_} -> {error, {bad_action_from_state_function,Action}, ?STACKTRACE()}; - {timeout,infinity,_} -> % Clear timer - it will never trigger + {timeout,infinity,_} -> + %% Ignore - timeout will never happen and already cancelled parse_actions( Debug, S, State, Actions, - Hibernate, undefined, StateTimeout, Postpone, NextEvents); - {timeout,Time,_} = NewTimeout when is_integer(Time), Time >= 0 -> + Hibernate, TimeoutsR, Postpone, NextEventsR); + {timeout,Time,_} = Timeout when is_integer(Time), Time >= 0 -> parse_actions( Debug, S, State, Actions, - Hibernate, NewTimeout, StateTimeout, Postpone, NextEvents); + Hibernate, [Timeout|TimeoutsR], Postpone, NextEventsR); {timeout,_,_} -> {error, {bad_action_from_state_function,Action}, ?STACKTRACE()}; - infinity -> % Clear timer - it will never trigger + infinity -> % Ignore - timeout will never happen parse_actions( Debug, S, State, Actions, - Hibernate, undefined, StateTimeout, Postpone, NextEvents); + Hibernate, TimeoutsR, Postpone, NextEventsR); Time when is_integer(Time), Time >= 0 -> - NewTimeout = {timeout,Time,Time}, + Timeout = {timeout,Time,Time}, parse_actions( Debug, S, State, Actions, - Hibernate, NewTimeout, StateTimeout, Postpone, NextEvents); + Hibernate, [Timeout|TimeoutsR], Postpone, NextEventsR); {postpone,NewPostpone} when is_boolean(NewPostpone), Postpone =/= forbidden -> parse_actions( Debug, S, State, Actions, - Hibernate, Timeout, StateTimeout, NewPostpone, NextEvents); + Hibernate, TimeoutsR, NewPostpone, NextEventsR); {postpone,_} -> {error, {bad_action_from_state_function,Action}, @@ -1243,16 +1333,16 @@ parse_actions( postpone when Postpone =/= forbidden -> parse_actions( Debug, S, State, Actions, - Hibernate, Timeout, StateTimeout, true, NextEvents); + Hibernate, TimeoutsR, true, NextEventsR); {next_event,Type,Content} -> case event_type(Type) of - true when NextEvents =/= forbidden -> + true when NextEventsR =/= forbidden -> NewDebug = sys_debug(Debug, S, State, {in,{Type,Content}}), parse_actions( NewDebug, S, State, Actions, - Hibernate, Timeout, StateTimeout, - Postpone, [{Type,Content}|NextEvents]); + Hibernate, TimeoutsR, Postpone, + [{Type,Content}|NextEventsR]); _ -> {error, {bad_action_from_state_function,Action}, @@ -1264,158 +1354,59 @@ parse_actions( ?STACKTRACE()} end. -loop_event_actions( - Parent, Debug, - #{state := State, state_enter := StateEnter} = S, StateTimer, - Events, Event, NextState, NewData, Actions) -> - case parse_actions(Debug, S, State, Actions) of - {ok,NewDebug,Hibernate,Timeout,StateTimeout,Postpone,NextEvents} -> - if - StateEnter, NextState =/= State -> - loop_event_enter( - Parent, NewDebug, S, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, Postpone, NextEvents); - StateEnter -> - case maps:is_key(init_state, S) of - true -> - %% Avoid infinite loop in initial state - %% with state entry events - NewS = maps:remove(init_state, S), - loop_event_enter( - Parent, NewDebug, NewS, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, - Postpone, NextEvents); - false -> - loop_event_result( - Parent, NewDebug, S, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, - Postpone, NextEvents) - end; - true -> - loop_event_result( - Parent, NewDebug, S, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, Postpone, NextEvents) - end; - {Class,Reason,Stacktrace} -> - terminate( - Class, Reason, Stacktrace, - Debug, S#{data := NewData}, [Event|Events]) - end. -loop_event_enter( - Parent, Debug, #{state := State} = S, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, Postpone, NextEvents) -> - case call_state_function(S, enter, State, NextState, NewData) of - {ok,Result,NewS} -> - {NewerData,_,Actions} = - parse_event_result( - false, Debug, NewS, Result, - Events, Event, NextState, NewData), - loop_event_enter_actions( - Parent, Debug, NewS, StateTimer, - Events, Event, NextState, NewerData, - Hibernate, Timeout, StateTimeout, Postpone, NextEvents, Actions); - {Class,Reason,Stacktrace} -> - terminate( - Class, Reason, Stacktrace, - Debug, S#{state := NextState, data := NewData}, - [Event|Events]) +%% Stop and start timers as well as create timeout zero events +%% +handle_timers(TimerRefs, TimerTypes, TimeoutsR) -> + Seen = #{}, + TimeoutEvents = [], + handle_timers(TimerRefs, TimerTypes, TimeoutsR, Seen, TimeoutEvents). +%% +handle_timers(TimerRefs, TimerTypes, [], _Seen, TimeoutEvents) -> + {TimerRefs,TimerTypes,TimeoutEvents}; +handle_timers(TimerRefs, TimerTypes, [Timeout|TimeoutsR], Seen, TimeoutEvents) -> + {TimerType,Time,TimerMsg} = Timeout, + case Seen of + #{TimerType := _} -> + handle_timers( + TimerRefs, TimerTypes, TimeoutsR, Seen, TimeoutEvents); + #{} -> + NewSeen = Seen#{TimerType => true}, + {NewTimerRefs,NewTimerTypes} = + cancel_timer_by_type(TimerType, TimerRefs, TimerTypes), + case Time of + 0 -> + TimeoutEvent = {TimerType,TimerMsg}, + handle_timers( + NewTimerRefs, NewTimerTypes, + TimeoutsR, NewSeen, [TimeoutEvent|TimeoutEvents]); + infinity -> + %% Ignore - timer will never fire + handle_timers( + NewTimerRefs, NewTimerTypes, + TimeoutsR, NewSeen, TimeoutEvents); + _ -> + TimerRef = erlang:start_timer(Time, self(), TimerMsg), + handle_timers( + NewTimerRefs#{TimerRef => TimerType}, + NewTimerTypes#{TimerType => TimerRef}, + TimeoutsR, NewSeen, TimeoutEvents) + end end. -loop_event_enter_actions( - Parent, Debug, S, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, Postpone, NextEvents, Actions) -> - case - parse_enter_actions( - Debug, S, NextState, Actions, - Hibernate, Timeout, StateTimeout) - of - {ok,NewDebug,NewHibernate,NewTimeout,NewStateTimeout,_,_} -> - loop_event_result( - Parent, NewDebug, S, StateTimer, - Events, Event, NextState, NewData, - NewHibernate, NewTimeout, NewStateTimeout, Postpone, NextEvents); - {Class,Reason,Stacktrace} -> - terminate( - Class, Reason, Stacktrace, - Debug, S#{state := NextState, data := NewData}, - [Event|Events]) - end. -loop_event_result( - Parent, Debug, - #{state := State, postponed := P_0} = S, StateTimer, - Events, Event, NextState, NewData, - Hibernate, Timeout, StateTimeout, Postpone, NextEvents) -> - %% - %% All options have been collected and next_events are buffered. - %% Do the actual state transition. - %% - NewStateTimeout = - case StateTimeout of - {state_timeout,Time,_} -> - %% New timeout -> cancel timer - case StateTimer of - {state_timeout,_,_} -> - ok; - _ -> - cancel_timer(StateTimer) - end, - case Time of - infinity -> - undefined; - _ -> - StateTimeout - end; - undefined when NextState =/= State -> - %% State change -> cancel timer - case StateTimer of - {state_timeout,_,_} -> - ok; - _ -> - cancel_timer(StateTimer) - end, - undefined; - undefined -> - StateTimer - end, - %% - P_1 = % Move current event to postponed if Postpone - case Postpone of - true -> - [Event|P_0]; - false -> - P_0 - end, - {Events_1,NewP} = % Move all postponed events to queue if state change - if - NextState =:= State -> - {Events,P_1}; - true -> - {lists:reverse(P_1, Events),[]} - end, - %% Place next events first in queue - NewEvents = lists:reverse(NextEvents, Events_1), - %% - NewDebug = - sys_debug( - Debug, S, State, - case Postpone of - true -> - {postpone,Event,State}; - false -> - {consume,Event,State} - end), - %% - loop_events( - Parent, NewDebug, S, NewStateTimeout, - NewEvents, Timeout, NextState, NewData, NewP, Hibernate). +%% Keep an event timeout event if it is the only event so far +process_timeout_events([], _Es) -> + []; +process_timeout_events([{timeout,_} = TimeoutEvent|TimeoutEvents], []) -> + [TimeoutEvent|process_timeout_events(TimeoutEvents, [TimeoutEvent])]; +process_timeout_events([{timeout,_}|TimeoutEvents], Es) -> + %% Ignore event timeout since there are other events + process_timeout_events(TimeoutEvents, Es); +process_timeout_events([TimeoutEvent|TimeoutEvents], Es) -> + [TimeoutEvent|process_timeout_events(TimeoutEvents, [TimeoutEvent|Es])]. + + %%--------------------------------------------------------------------------- %% Server helpers @@ -1605,8 +1596,19 @@ listify(Item) when is_list(Item) -> listify(Item) -> [Item]. -cancel_timer(undefined) -> - ok; +%% Cancel timer if running, otherwise no op +cancel_timer_by_type(TimerType, TimerRefs, TimerTypes) -> + case TimerTypes of + #{TimerType := TimerRef} -> + cancel_timer(TimerRef), + {maps:remove(TimerRef, TimerRefs), + maps:remove(TimerType, TimerTypes)}; + #{} -> + {TimerRefs,TimerTypes} + end. + +%%cancel_timer(undefined) -> +%% ok; cancel_timer(TRef) -> case erlang:cancel_timer(TRef) of false -> diff --git a/lib/stdlib/test/gen_statem_SUITE.erl b/lib/stdlib/test/gen_statem_SUITE.erl index 28f9ab81fe..119546be98 100644 --- a/lib/stdlib/test/gen_statem_SUITE.erl +++ b/lib/stdlib/test/gen_statem_SUITE.erl @@ -742,26 +742,40 @@ state_timeout(_Config) -> %% Verify that {state_timeout,0,_} %% comes after next_event and that %% {timeout,0,_} is cancelled by - %% {state_timeout,0,_} + %% pending {state_timeout,0,_} {keep_state, {ok,2,Data}, [{timeout,0,3}]}; - (state_timeout, 2, {ok,2,{Time,From}}) -> - {next_state, state3, 3, + (state_timeout, 2, {ok,2,Data}) -> + %% Verify that timeout 0's are processed + %% in order + {keep_state, {ok,3,Data}, + [{timeout,0,4},{state_timeout,0,5}]}; + (timeout, 4, {ok,3,Data}) -> + %% Verify that timeout 0 is cancelled by + %% enqueued state_timeout 0 and that + %% multiple state_timeout 0 can be enqueued + {keep_state, {ok,4,Data}, + [{state_timeout,0,6},{timeout,0,7}]}; + (state_timeout, 5, {ok,4,Data}) -> + {keep_state, {ok,5,Data}}; + (state_timeout, 6, {ok,5,{Time,From}}) -> + {next_state, state3, 6, [{reply,From,ok}, - {state_timeout,Time,3}]} + {state_timeout,Time,8}]} end, state3 => fun - (info, message_to_self, 3) -> - {keep_state, '3'}; - ({call,From}, check, '3') -> + (info, message_to_self, 6) -> + {keep_state, 7}; + ({call,From}, check, 7) -> {keep_state, From}; - (state_timeout, 3, From) -> + (state_timeout, 8, From) -> {stop_and_reply, normal, {reply,From,ok}} end}, {ok,STM} = gen_statem:start_link(?MODULE, {map_statem,Machine,[]}, []), + sys:trace(STM, true), TRef = erlang:start_timer(1000, self(), kull), ok = gen_statem:call(STM, {go,500}), ok = gen_statem:call(STM, check), |