From 61935c77915a8e206a82cba1c9c9f64be462905d Mon Sep 17 00:00:00 2001 From: Raimo Niskanen Date: Thu, 21 Jun 2018 09:53:55 +0200 Subject: Clean up and optimize code and doc --- lib/stdlib/src/gen_statem.erl | 261 +++++++++++++++++++++++------------------- 1 file changed, 142 insertions(+), 119 deletions(-) (limited to 'lib/stdlib/src/gen_statem.erl') diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index faa43fbc1e..24b268cd38 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -330,6 +330,7 @@ %% Type validation functions +%% - return true if the value is of the type, false otherwise -compile( {inline, [callback_mode/1, state_enter/1, @@ -1277,7 +1278,7 @@ parse_actions(StateCall, Debug, S, [Action|Actions], TransOpts) -> end. parse_actions_reply( - StateCall, ?not_sys_debug, S, Actions, TransOpts, + StateCall, ?not_sys_debug = Debug, S, Actions, TransOpts, From, Reply) -> %% case from(From) of @@ -1287,8 +1288,7 @@ parse_actions_reply( false -> [error, {bad_action_from_state_function,{reply,From,Reply}}, - ?STACKTRACE(), - ?not_sys_debug] + ?STACKTRACE(), Debug] end; parse_actions_reply( StateCall, Debug, #state{name = Name, state = State} = S, @@ -1302,12 +1302,11 @@ parse_actions_reply( false -> [error, {bad_action_from_state_function,{reply,From,Reply}}, - ?STACKTRACE(), - Debug] + ?STACKTRACE(), Debug] end. parse_actions_next_event( - StateCall, ?not_sys_debug, S, + StateCall, ?not_sys_debug = Debug, S, Actions, TransOpts, Type, Content) -> case event_type(Type) of true when StateCall -> @@ -1320,8 +1319,7 @@ parse_actions_next_event( [error, {bad_state_enter_action_from_state_function, {next_event,Type,Content}}, - ?STACKTRACE(), - ?not_sys_debug] + ?STACKTRACE(), Debug] end; parse_actions_next_event( StateCall, Debug, #state{name = Name, state = State} = S, @@ -1403,13 +1401,13 @@ parse_actions_timeout_add( loop_event_done( Parent, ?not_sys_debug, #state{postponed = P} = S, +%% #state{postponed = will_not_happen = P} = S, Events, Event, NextState, NewData, #trans_opts{ postpone = Postpone, hibernate = Hibernate, - timeouts_r = [], next_events_r = []}) -> + timeouts_r = [], next_events_r = NextEventsR}) -> %% - %% Optimize the simple cases - %% i.e no timer changes, no inserted events and no debug, + %% Optimize the simple cases i.e no debug and no timer changes, %% by duplicate stripped down code %% %% Fast path @@ -1417,14 +1415,12 @@ loop_event_done( case Postpone of true -> loop_event_done_fast( - Parent, Hibernate, - S, - Events, [Event|P], NextState, NewData); + Parent, Hibernate, S, + Events, [Event|P], NextState, NewData, NextEventsR); false -> loop_event_done_fast( - Parent, Hibernate, - S, - Events, P, NextState, NewData) + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR) end; loop_event_done( Parent, Debug_0, @@ -1456,26 +1452,23 @@ loop_event_done( {S#state.name,State}, {consume,Event_0,NextState})|P_0] end, - {Events_2,P_2,Timers_2} = - %% Move all postponed events to queue, - %% cancel the event timer, - %% and cancel the state timeout if the state changes - if - NextState =:= State -> - {Events_0,P_1, + {Events_2,P_2, + Timers_2} = + %% Cancel the event timeout + if + NextState =:= State -> + {Events_0,P_1, cancel_timer_by_type( timeout, {TimerTypes_0,CancelTimers_0})}; - true -> - {lists:reverse(P_1, Events_0), - [], - cancel_timer_by_type( - state_timeout, + true -> + %% Move all postponed events to queue + %% and cancel the state timeout + {lists:reverse(P_1, Events_0),[], + cancel_timer_by_type( + state_timeout, cancel_timer_by_type( timeout, {TimerTypes_0,CancelTimers_0}))} - %% The state timer is removed from TimerTypes - %% but remains in TimerRefs until we get - %% the cancel_timer msg - end, + end, {TimerRefs_3,{TimerTypes_3,CancelTimers_3},TimeoutEvents} = %% Stop and start timers parse_timers(TimerRefs_0, Timers_2, TimeoutsR), @@ -1495,114 +1488,144 @@ loop_event_done( hibernate = Hibernate}, lists:reverse(Events_4R)). +loop_event_done(Parent, Debug, S, Q) -> +%% io:format( +%% "loop_event_done:~n" +%% " state = ~p, data = ~p, postponed = ~p~n " +%% " timer_refs = ~p, timer_types = ~p, cancel_timers = ~p.~n" +%% " Q = ~p.~n", +%% [S#state.state,S#state.data,S#state.postponed, +%% S#state.timer_refs,S#state.timer_types,S#state.cancel_timers, +%% Q]), + case Q of + [] -> + %% Get a new event + loop(Parent, Debug, S); + [{Type,Content}|Events] -> + %% Loop until out of enqueued events + loop_event(Parent, Debug, S, Events, Type, Content) + end. + + %% Fast path %% +%% Cancel event timer and state timer only if running loop_event_done_fast( Parent, Hibernate, #state{ state = NextState, - timer_types = #{timeout := _} = TimerTypes, + timer_types = TimerTypes, cancel_timers = CancelTimers} = S, - Events, P, NextState, NewData) -> - %% - %% Same state, event timeout active - %% - loop_event_done_fast( - Parent, Hibernate, S, - Events, P, NextState, NewData, - cancel_timer_by_type( - timeout, {TimerTypes,CancelTimers})); -loop_event_done_fast( - Parent, Hibernate, - #state{state = NextState} = S, - Events, P, NextState, NewData) -> - %% + Events, P, NextState, NewData, NextEventsR) -> %% Same state - %% - loop_event_done( - Parent, ?not_sys_debug, - S#state{ - data = NewData, - postponed = P, - hibernate = Hibernate}, - Events); -loop_event_done_fast( - Parent, Hibernate, - #state{ - timer_types = #{timeout := _} = TimerTypes, - cancel_timers = CancelTimers} = S, - Events, P, NextState, NewData) -> - %% - %% State change, event timeout active - %% - loop_event_done_fast( - Parent, Hibernate, S, - lists:reverse(P, Events), [], NextState, NewData, - cancel_timer_by_type( - state_timeout, - cancel_timer_by_type( - timeout, {TimerTypes,CancelTimers}))); + case TimerTypes of + #{timeout := _} -> + %% Event timeout active + loop_event_done_fast_2( + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR, + cancel_timer_by_type( + timeout, {TimerTypes,CancelTimers})); + _ -> + %% No event timeout active + loop_event_done_fast_2( + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR, + {TimerTypes,CancelTimers}) + end; loop_event_done_fast( Parent, Hibernate, #state{ - timer_types = #{state_timeout := _} = TimerTypes, + timer_types = TimerTypes, cancel_timers = CancelTimers} = S, - Events, P, NextState, NewData) -> - %% - %% State change, state timeout active - %% - loop_event_done_fast( - Parent, Hibernate, S, - lists:reverse(P, Events), [], NextState, NewData, - cancel_timer_by_type( - state_timeout, - cancel_timer_by_type( - timeout, {TimerTypes,CancelTimers}))); + Events, P, NextState, NewData, NextEventsR) -> + %% State change + case TimerTypes of + #{timeout := _} -> + %% Event timeout active + %% - cancel state_timeout too since it is faster than inspecting + loop_event_done_fast( + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR, + cancel_timer_by_type( + state_timeout, + cancel_timer_by_type( + timeout, {TimerTypes,CancelTimers}))); + #{state_timeout := _} -> + %% State_timeout active but not event timeout + loop_event_done_fast( + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR, + cancel_timer_by_type( + state_timeout, {TimerTypes,CancelTimers})); + _ -> + %% No event nor state_timeout active + loop_event_done_fast( + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR, + {TimerTypes,CancelTimers}) + end. +%% +%% Retry postponed events loop_event_done_fast( - Parent, Hibernate, - #state{} = S, - Events, P, NextState, NewData) -> - %% - %% State change, no timeout to automatically cancel - %% - loop_event_done( - Parent, ?not_sys_debug, - S#state{ - state = NextState, - data = NewData, - postponed = [], - hibernate = Hibernate}, - lists:reverse(P, Events)). + Parent, Hibernate, S, + Events, P, NextState, NewData, NextEventsR, TimerTypes_CancelTimers) -> + case P of + %% Handle 0..2 postponed events without list reversal since + %% that will move out all live registers and back again + [] -> + loop_event_done_fast_2( + Parent, Hibernate, S, + Events, [], NextState, NewData, NextEventsR, + TimerTypes_CancelTimers); + [E] -> + loop_event_done_fast_2( + Parent, Hibernate, S, + [E|Events], [], NextState, NewData, NextEventsR, + TimerTypes_CancelTimers); + [E1,E2] -> + loop_event_done_fast_2( + Parent, Hibernate, S, + [E2,E1|Events], [], NextState, NewData, NextEventsR, + TimerTypes_CancelTimers); + _ -> + %% A bit slower path + loop_event_done_fast_2( + Parent, Hibernate, S, + lists:reverse(P, Events), [], NextState, NewData, NextEventsR, + TimerTypes_CancelTimers) + end. %% %% Fast path %% -loop_event_done_fast( +loop_event_done_fast_2( Parent, Hibernate, S, - Events, P, NextState, NewData, + Events, P, NextState, NewData, NextEventsR, {TimerTypes,CancelTimers}) -> %% - loop_event_done( - Parent, ?not_sys_debug, - S#state{ - state = NextState, - data = NewData, - postponed = P, - timer_types = TimerTypes, - cancel_timers = CancelTimers, - hibernate = Hibernate}, - Events). - -loop_event_done(Parent, Debug, S, Q) -> - case Q of + NewS = + S#state{ + state = NextState, + data = NewData, + postponed = P, + timer_types = TimerTypes, + cancel_timers = CancelTimers, + hibernate = Hibernate}, + case NextEventsR of + %% Handle 0..2 next events without list reversal since + %% that will move out all live registers and back again [] -> - %% Get a new event - loop(Parent, Debug, S); - [{Type,Content}|Events] -> - %% Loop until out of enqueued events - loop_event(Parent, Debug, S, Events, Type, Content) + loop_event_done(Parent, ?not_sys_debug, NewS, Events); + [E] -> + loop_event_done(Parent, ?not_sys_debug, NewS, [E|Events]); + [E2,E1] -> + loop_event_done(Parent, ?not_sys_debug, NewS, [E1,E2|Events]); + _ -> + %% A bit slower path + loop_event_done( + Parent, ?not_sys_debug, NewS, lists:reverse(NextEventsR, Events)) end. - %%--------------------------------------------------------------------------- %% Server loop helpers -- cgit v1.2.3