From 681b30df0caff7157c0c75aaeeaa8f38d194f2b2 Mon Sep 17 00:00:00 2001 From: Raimo Niskanen Date: Mon, 6 Feb 2017 16:06:08 +0100 Subject: Clean up timer handling --- lib/stdlib/src/gen_statem.erl | 112 +++++++++++++++++++++++++----------------- 1 file changed, 66 insertions(+), 46 deletions(-) (limited to 'lib/stdlib') diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index 15c01c1006..6d9a828319 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -948,20 +948,38 @@ loop_receive(Parent, Debug, S) -> end. loop_receive_result( - Parent, Debug, #{state := State} = S, Hibernate, Event) -> + Parent, Debug, + #{state := State, + timer_types := TimerTypes, cancel_timers := CancelTimers} = 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 is the queue of not yet handled events created Events = [], - loop_event(Parent, NewDebug, S, Events, Event, Hibernate). + %% Cancel any running event timer + case + cancel_timer_by_type(timeout, TimerTypes, CancelTimers) + of + {_,CancelTimers} -> + %% No timer cancelled + loop_event(Parent, NewDebug, S, Events, Event, Hibernate); + {NewTimerTypes,NewCancelTimers} -> + %% The timer is removed from NewTimerTypes but + %% remains in TimerRefs until we get + %% the cancel_timer msg + NewS = + S#{ + timer_types := NewTimerTypes, + cancel_timers := NewCancelTimers}, + loop_event(Parent, NewDebug, NewS, Events, Event, Hibernate) + end. %% Entry point for handling an event, received or enqueued loop_event( Parent, Debug, - #{state := State, data := Data, timer_types := TimerTypes, - cancel_timers := CancelTimers} = S_0, + #{state := State, data := Data} = S, Events, {Type,Content} = Event, Hibernate) -> %% %% If (this old) Hibernate is true here it can only be @@ -972,34 +990,18 @@ loop_event( %% would have happened if we actually hibernated %% and immediately was awakened Hibernate andalso garbage_collect(), - case call_state_function(S_0, Type, Content, State, Data) of - {ok,Result,S_1} -> - %% Cancel event timeout - 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, + case call_state_function(S, Type, Content, State, Data) of + {ok,Result,NewS} -> {NextState,NewData,Actions,EnterCall} = parse_event_result( - true, Debug, S_2, + true, Debug, NewS, Events, Event, State, Data, Result), loop_event_actions( - Parent, Debug, S_2, + Parent, Debug, NewS, Events, Event, NextState, NewData, Actions, EnterCall); {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, Debug, S_0, + Class, Reason, Stacktrace, Debug, S, [Event|Events]) end. @@ -1412,7 +1414,7 @@ parse_actions( {bad_action_from_state_function,Action}, ?STACKTRACE()}; {timeout,infinity,_} -> - %% Ignore - timeout will never happen and already cancelled + %% Ignore - timeout will never happen and is already cancelled parse_actions( Debug, S, State, Actions, Hibernate, TimeoutsR, Postpone, NextEventsR); @@ -1467,7 +1469,6 @@ parse_actions( ?STACKTRACE()} end. - %% Stop and start timers as well as create timeout zero events %% and pending event timer %% @@ -1491,36 +1492,52 @@ parse_timers( #{} -> %% Unseen type - handle NewSeen = Seen#{TimerType => true}, - %% Cancel any running timer - {NewTimerTypes,NewCancelTimers} = - cancel_timer_by_type(TimerType, TimerTypes, CancelTimers), - %% This removes it from NewTimerTypes but its ref stays - %% in TimerRefs until we get the cancel_timer msg if - Time =:= infinity -> - %% Ignore - timer will never fire - parse_timers( - TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, - NewSeen, TimeoutEvents); TimerType =:= timeout -> %% Handle event timer later parse_timers( - TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, + TimerRefs, TimerTypes, CancelTimers, TimeoutsR, NewSeen, [Timeout|TimeoutEvents]); + Time =:= infinity -> + %% Cancel any running timer + {NewTimerTypes,NewCancelTimers} = + cancel_timer_by_type( + TimerType, TimerTypes, CancelTimers), + parse_timers( + TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, + NewSeen, TimeoutEvents); Time =:= 0 -> + %% Cancel any running timer + {NewTimerTypes,NewCancelTimers} = + cancel_timer_by_type( + TimerType, TimerTypes, CancelTimers), %% Handle zero time timeouts later TimeoutEvent = {TimerType,TimerMsg}, parse_timers( TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, NewSeen, [TimeoutEvent|TimeoutEvents]); true -> - %% Start a new timer - TimerRef = erlang:start_timer(Time, self(), TimerMsg), - %% Insert it both into TimerRefs and TimerTypes - parse_timers( - TimerRefs#{TimerRef => TimerType}, - NewTimerTypes#{TimerType => TimerRef}, - NewCancelTimers, TimeoutsR, NewSeen, TimeoutEvents) + %% (Re)start the timer + TimerRef = + erlang:start_timer(Time, self(), TimerMsg), + case TimerTypes of + #{TimerType := OldTimerRef} -> + %% Cancel the running timer + cancel_timer(OldTimerRef), + %% Insert the new timer into + %% both TimerRefs and TimerTypes + parse_timers( + TimerRefs#{TimerRef => TimerType}, + TimerTypes#{TimerType => TimerRef}, + CancelTimers + 1, + TimeoutsR, NewSeen, TimeoutEvents); + #{} -> + parse_timers( + TimerRefs#{TimerRef => TimerType}, + TimerTypes#{TimerType => TimerRef}, + CancelTimers, + TimeoutsR, NewSeen, TimeoutEvents) + end end end. @@ -1762,8 +1779,11 @@ listify(Item) -> cancel_timer_by_type(TimerType, TimerTypes, CancelTimers) -> case TimerTypes of #{TimerType := TimerRef} -> - _ = erlang:cancel_timer(TimerRef, [{async,true}]), + cancel_timer(TimerRef), {maps:remove(TimerType, TimerTypes),CancelTimers + 1}; #{} -> {TimerTypes,CancelTimers} end. + +cancel_timer(TimerRef) -> + ok = erlang:cancel_timer(TimerRef, [{async,true}]). -- cgit v1.2.3