diff options
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 167 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 867 | ||||
| -rw-r--r-- | lib/stdlib/test/gen_statem_SUITE.erl | 105 | ||||
| -rw-r--r-- | lib/tools/emacs/erlang-skels.el | 14 | ||||
| -rw-r--r-- | system/doc/design_principles/statem.xml | 11 |
5 files changed, 700 insertions, 464 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index fd498ee82e..5eb13db1aa 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2016</year> + <year>2016-2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -587,8 +587,8 @@ handle_event(_, _, State, Data) -> <name name="state_enter"/> <desc> <p> - If the state machine should use <em>state enter calls</em> - is selected when starting the <c>gen_statem</c> + Whether the state machine should use <em>state enter calls</em> + or not is selected when starting the <c>gen_statem</c> and after code change using the return value from <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso>. </p> @@ -606,7 +606,16 @@ handle_event(_, _, State, Data) -> See <seealso marker="#Module:StateName/3"><c>Module:StateName/3</c></seealso> and - <seealso marker="#Module:handle_event/4"><c>Module:handle_event/4</c></seealso>. + <seealso marker="#Module:handle_event/4"><c>Module:handle_event/4</c></seealso>. + Such a call can be repeated by returning a + <seealso marker="#type-state_callback_result"> + <c>repeat_state</c> + </seealso> + or + <seealso marker="#type-state_callback_result"> + <c>repeat_state_and_data</c> + </seealso> + tuple from the state callback. </p> <p> If @@ -625,7 +634,8 @@ handle_event(_, _, State, Data) -> right before entering the initial state even though this formally is not a state change. In this case <c>OldState</c> will be the same as <c>State</c>, - which can not happen for a subsequent state change. + which can not happen for a subsequent state change, + but will happen when repeating the state enter call. </p> </desc> </datatype> @@ -640,7 +650,15 @@ handle_event(_, _, State, Data) -> <list type="ordered"> <item> <p> - If the state changes or is the initial state, and + If the state changes, is the initial state, + <seealso marker="#type-state_callback_result"> + <c>repeat_state</c> + </seealso> + or + <seealso marker="#type-state_callback_result"> + <c>repeat_state_and_data</c> + </seealso> + is used, and also <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 @@ -983,6 +1001,33 @@ handle_event(_, _, State, Data) -> </desc> </datatype> <datatype> + <name name="init_result"/> + <desc> + <p> + For a succesful initialization, + <c><anno>State</anno></c> is the initial + <seealso marker="#type-state"><c>state()</c></seealso> + and <c><anno>Data</anno></c> the initial server + <seealso marker="#type-data"><c>data()</c></seealso> + of the <c>gen_statem</c>. + </p> + <p> + The <seealso marker="#type-action"><c>Actions</c></seealso> + are executed when entering the first + <seealso marker="#type-state">state</seealso> just as for a + <seealso marker="#state callback">state callback</seealso>, + except that the action <c>postpone</c> is forced to + <c>false</c> since there is no event to postpone. + </p> + <p> + For an unsuccesful initialization, + <c>{stop,<anno>Reason</anno>}</c> + or <c>ignore</c> should be used; see + <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>. + </p> + </desc> + </datatype> + <datatype> <name name="state_enter_result"/> <desc> <p> @@ -1068,6 +1113,37 @@ handle_event(_, _, State, Data) -> <c>{next_state,CurrentState,CurrentData,<anno>Actions</anno>}</c>. </p> </item> + <tag><c>repeat_state</c></tag> + <item> + <p> + The <c>gen_statem</c> keeps the current state, or + does a state transition to the current state if you like, + sets <c><anno>NewData</anno></c>, + and executes all <c><anno>Actions</anno></c>. + If the <c>gen_statem</c> runs with + <seealso marker="#type-state_enter"><em>state enter calls</em></seealso>, + the state enter call is repeated, see type + <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>, + otherwise <c>repeat_state</c> is the same as + <c>keep_state</c>. + </p> + </item> + <tag><c>repeat_state_and_data</c></tag> + <item> + <p> + The <c>gen_statem</c> keeps the current state and data, or + does a state transition to the current state if you like, + and executes all <c><anno>Actions</anno></c>. + This is the same as + <c>{repeat_state,CurrentData,<anno>Actions</anno>}</c>. + If the <c>gen_statem</c> runs with + <seealso marker="#type-state_enter"><em>state enter calls</em></seealso>, + the state enter call is repeated, see type + <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>, + otherwise <c>repeat_state_and_data</c> is the same as + <c>keep_state_and_data</c>. + </p> + </item> <tag><c>stop</c></tag> <item> <p> @@ -1609,29 +1685,33 @@ handle_event(_, _, State, Data) -> It is recommended to use an atom as <c>Reason</c> since it will be wrapped in an <c>{error,Reason}</c> tuple. </p> + <p> + Also note when upgrading a <c>gen_statem</c>, + this function and hence + the <c>Change={advanced,Extra}</c> parameter in the + <seealso marker="sasl:appup"><c>appup</c></seealso> file + is not only needed to update the internal state + or to act on the <c>Extra</c> argument. + It is also needed if an upgrade or downgrade should change + <seealso marker="#type-callback_mode"><em>callback mode</em></seealso>, + or else the callback mode after the code change + will not be honoured, + most probably causing a server crash. + </p> </desc> </func> <func> - <name>Module:init(Args) -> Result</name> + <name>Module:init(Args) -> Result(StateType)</name> <fsummary> Optional function for initializing process and internal state. </fsummary> <type> <v>Args = term()</v> - <v>Result = {ok,State,Data}</v> - <v> | {ok,State,Data,Actions}</v> - <v> | {stop,Reason} | ignore</v> - <v>State = <seealso marker="#type-state">state()</seealso></v> - <v> - Data = <seealso marker="#type-data">data()</seealso> - </v> <v> - Actions = - [<seealso marker="#type-action">action()</seealso>] | - <seealso marker="#type-action">action()</seealso> + Result(StateType) = + <seealso marker="#type-init_result">init_result(StateType)</seealso> </v> - <v>Reason = term()</v> </type> <desc> <marker id="Module:init-1"/> @@ -1644,30 +1724,9 @@ handle_event(_, _, State, Data) -> the implementation state and server data. </p> <p> - <c>Args</c> is the <c>Args</c> argument provided to the start + <c>Args</c> is the <c>Args</c> argument provided to that start function. </p> - <p> - If the initialization is successful, the function is to - return <c>{ok,State,Data}</c> or - <c>{ok,State,Data,Actions}</c>. - <c>State</c> is the initial - <seealso marker="#type-state"><c>state()</c></seealso> - and <c>Data</c> the initial server - <seealso marker="#type-data"><c>data()</c></seealso>. - </p> - <p> - The <seealso marker="#type-action"><c>Actions</c></seealso> - are executed when entering the first - <seealso marker="#type-state">state</seealso> just as for a - <seealso marker="#state callback">state callback</seealso>. - </p> - <p> - If the initialization fails, - the function is to return <c>{stop,Reason}</c> - or <c>ignore</c>; see - <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>. - </p> <note> <p> This callback is optional, so a callback module does not need @@ -1873,22 +1932,33 @@ handle_event(_, _, State, Data) -> <seealso marker="#type-enter_action">actions</seealso> that may be returned: <seealso marker="#type-postpone"><c>postpone()</c></seealso> - and + is not allowed since a <em>state enter call</em> is not + an event so there is no event to postpone, and <seealso marker="#type-action"><c>{next_event,_,_}</c></seealso> - are not allowed. + is not allowed since using <em>state enter calls</em> + should not affect how events are consumed and produced. You may also not change states from this call. Should you return <c>{next_state,NextState, ...}</c> with <c>NextState =/= State</c> the <c>gen_statem</c> crashes. - You are advised to use <c>{keep_state,...}</c> or - <c>keep_state_and_data</c>. + It is possible to use <c>{repeat_state, ...}</c>, + <c>{repeat_state_and_data,_}</c> or + <c>repeat_state_and_data</c> but all of them makes little + sense since you immediately will be called again with a new + <em>state enter call</em> making this just a weird way + of looping, and there are better ways to loop in Erlang. + You are advised to use <c>{keep_state,...}</c>, + <c>{keep_state_and_data,_}</c> or + <c>keep_state_and_data</c> since you can not change states + from a <em>state enter call</em> anyway. </p> <p> Note the fact that you can use <seealso marker="erts:erlang#throw/1"><c>throw</c></seealso> to return the result, which can be useful. For example to bail out with <c>throw(keep_state_and_data)</c> - from deep within complex code that is in no position to - return <c>{next_state,State,Data}</c>. + from deep within complex code that can not + return <c>{next_state,State,Data}</c> because + <c>State</c> or <c>Data</c> is no longer in scope. </p> </desc> </func> @@ -1903,6 +1973,11 @@ handle_event(_, _, State, Data) -> <v>Ignored = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_statem</c> module provides a default + implementation without cleanup.</p> + </note> <p> This function is called by a <c>gen_statem</c> when it is about to terminate. It is to be the opposite of diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index 018aca90e6..cacc932ec4 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2016. All Rights Reserved. +%% Copyright Ericsson AB 2016-2017. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -47,15 +47,17 @@ %% Type exports for templates and callback modules -export_type( [event_type/0, - init_result/0, callback_mode_result/0, - state_function_result/0, - handle_event_result/0, + init_result/1, state_enter_result/1, event_handler_result/1, reply_action/0, enter_action/0, action/0]). +%% Old types, not advertised +-export_type( + [state_function_result/0, + handle_event_result/0]). %% Type that is exported just to be documented -export_type([transition_option/0]). @@ -143,9 +145,10 @@ {'reply', % Reply to a caller From :: from(), Reply :: term()}. --type init_result() :: - {ok, state(), data()} | - {ok, state(), data(), [action()] | action()} | +-type init_result(StateType) :: + {ok, State :: StateType, Data :: data()} | + {ok, State :: StateType, Data :: data(), + Actions :: [action()] | action()} | 'ignore' | {'stop', Reason :: term()}. @@ -182,12 +185,23 @@ 'keep_state_and_data' | % {keep_state_and_data,[]} {'keep_state_and_data', % Keep state and data -> only actions Actions :: [ActionType] | ActionType} | + %% + {'repeat_state', % {repeat_state,NewData,[]} + NewData :: data()} | + {'repeat_state', % Repeat state, change data + NewData :: data(), + Actions :: [ActionType] | ActionType} | + 'repeat_state_and_data' | % {repeat_state_and_data,[]} + {'repeat_state_and_data', % Repeat state and data -> only actions + Actions :: [ActionType] | ActionType} | + %% 'stop' | % {stop,normal} {'stop', % Stop the server Reason :: term()} | {'stop', % Stop the server Reason :: term(), NewData :: data()} | + %% {'stop_and_reply', % Reply then stop the server Reason :: term(), Replies :: [reply_action()] | reply_action()} | @@ -201,7 +215,7 @@ %% the server is not running until this function has returned %% an {ok, ...} tuple. Thereafter the state callbacks are called %% for all events to this server. --callback init(Args :: term()) -> init_result(). +-callback init(Args :: term()) -> init_result(state()). %% This callback shall return the callback mode of the callback module. %% @@ -275,6 +289,8 @@ -optional_callbacks( [init/1, % One may use enter_loop/5,6,7 instead format_status/2, % Has got a default implementation + terminate/3, % Has got a default implementation + code_change/4, % Only needed by advanced soft upgrade %% state_name/3, % Example for callback_mode() =:= state_functions: %% there has to be a StateName/3 callback function @@ -304,12 +320,16 @@ event_type({call,From}) -> from(From); event_type(Type) -> case Type of + {call,From} -> + from(From); cast -> true; info -> true; timeout -> true; + state_timeout -> + true; internal -> true; _ -> @@ -588,6 +608,22 @@ enter(Module, Opts, State, Data, Server, Actions, Parent) -> true -> [Actions,{postpone,false}] end, + TimerRefs = #{}, + %% Key: timer ref + %% Value: the timer type i.e the timer's event type + %% + TimerTypes = #{}, + %% Key: timer type i.e the timer's event type + %% Value: timer ref + %% + %% We add a timer to both timer_refs and timer_types + %% when we start it. When we request an asynchronous + %% timer cancel we remove it from timer_types. When + %% the timer cancel message arrives we remove it from + %% timer_refs. + %% + Hibernate = false, + CancelTimers = 0, S = #{ callback_mode => undefined, state_enter => false, @@ -596,25 +632,25 @@ enter(Module, Opts, State, Data, Server, Actions, Parent) -> state => State, data => Data, postponed => P, - %% The rest of the fields are set from to the arguments to - %% 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 + %% The following fields are finally set from to the arguments to + %% 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, + cancel_timers => CancelTimers }, NewDebug = sys_debug(Debug, S, State, {enter,Event,State}), case call_callback_mode(S) of {ok,NewS} -> - TimerRefs = #{}, - TimerTypes = #{}, loop_event_actions( - Parent, NewDebug, NewS, TimerRefs, TimerTypes, - Events, Event, State, Data, NewActions); + Parent, NewDebug, NewS, + Events, Event, State, Data, NewActions, true); {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, - NewDebug, S, [Event|Events]) + Class, Reason, Stacktrace, NewDebug, + S, [Event|Events]) end. %%%========================================================================== @@ -683,9 +719,7 @@ system_continue(Parent, Debug, S) -> loop(Parent, Debug, S). system_terminate(Reason, _Parent, Debug, S) -> - terminate( - exit, Reason, ?STACKTRACE(), - Debug, S, []). + terminate(exit, Reason, ?STACKTRACE(), Debug, S, []). system_code_change( #{module := Module, @@ -796,23 +830,22 @@ wakeup_from_hibernate(Parent, Debug, S) -> %% and detours through sys:handle_system_message/7 and proc_lib:hibernate/3 %% Entry point for system_continue/3 -loop(Parent, Debug, #{hibernate := Hibernate} = S) -> - case Hibernate of - true -> - %% Does not return but restarts process at - %% wakeup_from_hibernate/3 that jumps to loop_receive/3 - proc_lib:hibernate( - ?MODULE, wakeup_from_hibernate, [Parent,Debug,S]), - error( - {should_not_have_arrived_here_but_instead_in, - {wakeup_from_hibernate,3}}); - false -> - loop_receive(Parent, Debug, S) - end. +loop(Parent, Debug, #{hibernate := true, cancel_timers := 0} = S) -> + loop_hibernate(Parent, Debug, S); +loop(Parent, Debug, S) -> + loop_receive(Parent, Debug, S). + +loop_hibernate(Parent, Debug, S) -> + %% Does not return but restarts process at + %% wakeup_from_hibernate/3 that jumps to loop_receive/3 + proc_lib:hibernate( + ?MODULE, wakeup_from_hibernate, [Parent,Debug,S]), + error( + {should_not_have_arrived_here_but_instead_in, + {wakeup_from_hibernate,3}}). %% Entry point for wakeup_from_hibernate/3 -loop_receive( - Parent, Debug, #{timer_refs := TimerRefs, timer_types := TimerTypes} = S) -> +loop_receive(Parent, Debug, S) -> receive Msg -> case Msg of @@ -821,30 +854,87 @@ loop_receive( %% 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, Hibernate); + 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, [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} -> - Event = {TimerType,TimerMsg}, - %% Unregister the triggered timeout + %% 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 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#{ + 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_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, - maps:remove(TimerRef, TimerRefs), - maps:remove(TimerType, TimerTypes), - 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 + %% of this timer so it is already + %% removed from TimerTypes + NewTimerRefs = + maps:remove(TimerRef, TimerRefs), + NewCancelTimers = CancelTimers - 1, + NewS = + S#{ + timer_refs := NewTimerRefs, + cancel_timers := NewCancelTimers}, + if + 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, Event) + Parent, Debug, S, Hibernate, Event) end; _ -> + %% External msg + #{hibernate := Hibernate} = S, Event = case Msg of {'$gen_call',From,Request} -> @@ -855,208 +945,212 @@ loop_receive( {info,Msg} end, loop_receive_result( - Parent, Debug, S, - TimerRefs, TimerTypes, Event) + Parent, Debug, S, Hibernate, Event) end end. 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 - %% + 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 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, 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} = S, TimerRefs, TimerTypes, + Parent, Debug, + #{state := State, data := Data} = S, 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(), 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} = + {NextState,NewData,Actions,EnterCall} = parse_event_result( - true, Debug, NewS, Result, - Events, Event, State, Data), + true, Debug, NewS, + Events, Event, State, Data, Result), loop_event_actions( - Parent, Debug, S, NewTimerRefs, NewTimerTypes, - Events, Event, NextState, NewData, Actions); + Parent, Debug, NewS, + Events, Event, NextState, NewData, Actions, EnterCall); {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, Debug, S, [Event|Events]) + 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) -> + #{state := State, state_enter := StateEnter} = S, + 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, NextState =/= State -> + StateEnter, EnterCall -> loop_event_enter( - Parent, NewDebug, S, TimerRefs, TimerTypes, + Parent, NewDebug, S, 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, + Parent, NewDebug, S, Events, Event, NextState, NewData, Hibernate, TimeoutsR, Postpone, NextEventsR) end; {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, - Debug, S#{data := NewData}, [Event|Events]) + Class, Reason, Stacktrace, Debug, S, + [Event|Events]) end. loop_event_enter( - Parent, Debug, #{state := State} = S, TimerRefs, TimerTypes, + Parent, Debug, #{state := State} = S, 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); + case parse_event_result( + false, Debug, NewS, + Events, Event, NextState, NewData, Result) of + {_,NewerData,Actions,EnterCall} -> + loop_event_enter_actions( + Parent, Debug, NewS, + Events, Event, NextState, NewerData, + Hibernate, TimeoutsR, Postpone, NextEventsR, + Actions, EnterCall) + end; {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, - Debug, S#{state := NextState, data := NewData}, + Class, Reason, Stacktrace, Debug, + S#{ + state := NextState, + data := NewData, + hibernate := Hibernate}, [Event|Events]) end. loop_event_enter_actions( - Parent, Debug, S, TimerRefs, TimerTypes, + Parent, Debug, #{state_enter := StateEnter} = S, Events, Event, NextState, NewData, - Hibernate, TimeoutsR, Postpone, NextEventsR, Actions) -> + Hibernate, TimeoutsR, Postpone, NextEventsR, + Actions, EnterCall) -> case parse_enter_actions( - Debug, S, NextState, Actions, - Hibernate, TimeoutsR) + 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); + if + StateEnter, EnterCall -> + loop_event_enter( + Parent, NewDebug, S, + Events, Event, NextState, NewData, + NewHibernate, NewTimeoutsR, Postpone, NextEventsR); + true -> + loop_event_result( + Parent, NewDebug, S, + Events, Event, NextState, NewData, + NewHibernate, NewTimeoutsR, Postpone, NextEventsR) + end; {Class,Reason,Stacktrace} -> terminate( - Class, Reason, Stacktrace, - Debug, S#{state := NextState, data := NewData}, + Class, Reason, Stacktrace, Debug, + S#{ + state := NextState, + data := NewData, + hibernate := Hibernate}, [Event|Events]) end. loop_event_result( - Parent, Debug, - #{state := State, postponed := P_0} = S, TimerRefs_0, TimerTypes_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,{TimerRefs_1,TimerTypes_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,{TimerRefs_0,TimerTypes_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, TimerRefs_0, TimerTypes_0)} + 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,TimeoutEvents} = - %% Stop and start timers non-event timers - parse_timers(TimerRefs_1, TimerTypes_1, TimeoutsR), + {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} = - process_timeout_events( - TimerRefs_2, TimerTypes_2, TimeoutEvents, Events_2R), - NewEvents = lists:reverse(Events_3R), - 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_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). - + Events_3R = prepend_timeout_events(TimeoutEvents, Events_2R), + S_1 = + S_0#{ + state := NextState, + data := NewData, + postponed := P_2, + timer_refs := TimerRefs_2, + timer_types := TimerTypes_2, + cancel_timers := CancelTimers_2, + hibernate := 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. %%--------------------------------------------------------------------------- @@ -1069,19 +1163,6 @@ call_callback_mode(#{module := Module} = S) -> catch CallbackMode -> callback_mode_result(S, CallbackMode); - error:undef -> - %% Process undef to check for the simple mistake - %% of calling a nonexistent state function - %% to make the undef more precise - case erlang:get_stacktrace() of - [{Module,callback_mode,[]=Args,_} - |Stacktrace] -> - {error, - {undef_callback,{Module,callback_mode,Args}}, - Stacktrace}; - Stacktrace -> - {error,undef,Stacktrace} - end; Class:Reason -> {Class,Reason,erlang:get_stacktrace()} end. @@ -1126,8 +1207,7 @@ 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); @@ -1135,13 +1215,12 @@ 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 state_functions -> - erlang:apply(Module, State, [Type,Content,Data]); + Module:State(Type, Content, Data); handle_event_function -> Module:handle_event(Type, Content, State, Data) end @@ -1151,41 +1230,6 @@ call_state_function( catch Result -> {ok,Result,S}; - error:badarg -> - case erlang:get_stacktrace() of - [{erlang,apply, - [Module,State,[Type,Content,Data]=Args], - _} - |Stacktrace] - when CallbackMode =:= state_functions -> - %% We get here e.g if apply fails - %% due to State not being an atom - {error, - {undef_state_function,{Module,State,Args}}, - Stacktrace}; - Stacktrace -> - {error,badarg,Stacktrace} - end; - error:undef -> - %% Process undef to check for the simple mistake - %% of calling a nonexistent state function - %% to make the undef more precise - case erlang:get_stacktrace() of - [{Module,State,[Type,Content,Data]=Args,_} - |Stacktrace] - when CallbackMode =:= state_functions -> - {error, - {undef_state_function,{Module,State,Args}}, - Stacktrace}; - [{Module,handle_event,[Type,Content,State,Data]=Args,_} - |Stacktrace] - when CallbackMode =:= handle_event_function -> - {error, - {undef_state_function,{Module,handle_event,Args}}, - Stacktrace}; - Stacktrace -> - {error,undef,Stacktrace} - end; Class:Reason -> {Class,Reason,erlang:get_stacktrace()} end. @@ -1193,65 +1237,83 @@ call_state_function( %% Interpret all callback return variants parse_event_result( - AllowStateChange, Debug, S, Result, Events, Event, State, Data) -> + AllowStateChange, Debug, S, + Events, Event, State, Data, Result) -> case Result of stop -> terminate( - exit, normal, ?STACKTRACE(), Debug, S, [Event|Events]); + exit, normal, ?STACKTRACE(), Debug, + S#{state := State, data := Data}, + [Event|Events]); {stop,Reason} -> terminate( - exit, Reason, ?STACKTRACE(), Debug, S, [Event|Events]); + exit, Reason, ?STACKTRACE(), Debug, + S#{state := State, data := Data}, + [Event|Events]); {stop,Reason,NewData} -> terminate( - exit, Reason, ?STACKTRACE(), - Debug, S#{data := NewData}, [Event|Events]); + exit, Reason, ?STACKTRACE(), Debug, + S#{state := State, data := NewData}, + [Event|Events]); + %% {stop_and_reply,Reason,Replies} -> - Q = [Event|Events], reply_then_terminate( - exit, Reason, ?STACKTRACE(), - Debug, S, Q, Replies); + exit, Reason, ?STACKTRACE(), Debug, + 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}, Q, Replies); + exit, Reason, ?STACKTRACE(), Debug, + S#{state := State, data := NewData}, + [Event|Events], Replies); + %% {next_state,State,NewData} -> - {NewData,State,[]}; + {State,NewData,[],false}; {next_state,NextState,NewData} when AllowStateChange -> - {NewData,NextState,[]}; + {NextState,NewData,[],true}; {next_state,State,NewData,Actions} -> - {NewData,State,Actions}; + {State,NewData,Actions,false}; {next_state,NextState,NewData,Actions} when AllowStateChange -> - {NewData,NextState,Actions}; + {NextState,NewData,Actions,true}; + %% {keep_state,NewData} -> - {NewData,State,[]}; + {State,NewData,[],false}; {keep_state,NewData,Actions} -> - {NewData,State,Actions}; + {State,NewData,Actions,false}; keep_state_and_data -> - {Data,State,[]}; + {State,Data,[],false}; {keep_state_and_data,Actions} -> - {Data,State,Actions}; + {State,Data,Actions,false}; + %% + {repeat_state,NewData} -> + {State,NewData,[],true}; + {repeat_state,NewData,Actions} -> + {State,NewData,Actions,true}; + repeat_state_and_data -> + {State,Data,[],true}; + {repeat_state_and_data,Actions} -> + {State,Data,Actions,true}; + %% _ -> terminate( error, {bad_return_from_state_function,Result}, - ?STACKTRACE(), - Debug, S, [Event|Events]) + ?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( Debug, S, State, listify(Actions), Hibernate, TimeoutsR, Postpone, NextEventsR). - + parse_actions(Debug, S, State, Actions) -> Hibernate = false, - TimeoutsR = [], + TimeoutsR = [{timeout,infinity,infinity}], %% Will cancel event timer Postpone = false, NextEventsR = [], parse_actions( @@ -1279,64 +1341,29 @@ parse_actions( {bad_action_from_state_function,Action}, ?STACKTRACE()} end; + %% %% Actions that set options {hibernate,NewHibernate} when is_boolean(NewHibernate) -> parse_actions( Debug, S, State, Actions, NewHibernate, TimeoutsR, Postpone, NextEventsR); - {hibernate,_} -> - {error, - {bad_action_from_state_function,Action}, - ?STACKTRACE()}; hibernate -> + NewHibernate = true, parse_actions( Debug, S, State, Actions, - true, TimeoutsR, Postpone, NextEventsR); - {state_timeout,Time,_} = StateTimeout - when is_integer(Time), Time >= 0; - Time =:= infinity -> - parse_actions( - Debug, S, State, Actions, - Hibernate, [StateTimeout|TimeoutsR], Postpone, NextEventsR); - {state_timeout,_,_} -> - {error, - {bad_action_from_state_function,Action}, - ?STACKTRACE()}; - {timeout,infinity,_} -> - %% Ignore - timeout will never happen and already cancelled - parse_actions( - Debug, S, State, Actions, - Hibernate, TimeoutsR, Postpone, NextEventsR); - {timeout,Time,_} = Timeout when is_integer(Time), Time >= 0 -> - parse_actions( - Debug, S, State, Actions, - Hibernate, [Timeout|TimeoutsR], Postpone, NextEventsR); - {timeout,_,_} -> - {error, - {bad_action_from_state_function,Action}, - ?STACKTRACE()}; - infinity -> % Ignore - timeout will never happen - parse_actions( - Debug, S, State, Actions, - Hibernate, TimeoutsR, Postpone, NextEventsR); - Time when is_integer(Time), Time >= 0 -> - Timeout = {timeout,Time,Time}, - parse_actions( - Debug, S, State, Actions, - Hibernate, [Timeout|TimeoutsR], Postpone, NextEventsR); + NewHibernate, TimeoutsR, Postpone, NextEventsR); + %% {postpone,NewPostpone} when is_boolean(NewPostpone), Postpone =/= forbidden -> parse_actions( Debug, S, State, Actions, Hibernate, TimeoutsR, NewPostpone, NextEventsR); - {postpone,_} -> - {error, - {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 -> @@ -1351,96 +1378,150 @@ parse_actions( {bad_action_from_state_function,Action}, ?STACKTRACE()} end; - _ -> + %% + {state_timeout,_,_} = Timeout -> + parse_actions_timeout( + Debug, S, State, Actions, + Hibernate, TimeoutsR, Postpone, NextEventsR, Timeout); + {timeout,_,_} = Timeout -> + parse_actions_timeout( + Debug, S, State, Actions, + Hibernate, TimeoutsR, Postpone, NextEventsR, Timeout); + Time -> + parse_actions_timeout( + Debug, S, State, Actions, + Hibernate, TimeoutsR, Postpone, NextEventsR, Time) + end. + +parse_actions_timeout( + Debug, S, State, Actions, + Hibernate, TimeoutsR, Postpone, NextEventsR, Timeout) -> + Time = + case Timeout of + {_,T,_} -> T; + T -> T + end, + case validate_time(Time) of + true -> + parse_actions( + Debug, S, State, Actions, + Hibernate, [Timeout|TimeoutsR], + Postpone, NextEventsR); + false -> {error, - {bad_action_from_state_function,Action}, + {bad_action_from_state_function,Timeout}, ?STACKTRACE()} end. +validate_time(Time) when is_integer(Time), Time >= 0 -> true; +validate_time(infinity) -> true; +validate_time(_) -> false. %% Stop and start timers as well as create timeout zero events %% and pending event timer %% %% Stop and start timers non-event timers -parse_timers(TimerRefs, TimerTypes, TimeoutsR) -> - parse_timers(TimerRefs, TimerTypes, TimeoutsR, #{}, []). +parse_timers(TimerRefs, TimerTypes, CancelTimers, TimeoutsR) -> + parse_timers(TimerRefs, TimerTypes, CancelTimers, TimeoutsR, #{}, []). %% -parse_timers(TimerRefs, TimerTypes, [], _Seen, TimeoutEvents) -> - {TimerRefs,TimerTypes,TimeoutEvents}; parse_timers( - TimerRefs, TimerTypes, [Timeout|TimeoutsR], Seen, TimeoutEvents) -> - {TimerType,Time,TimerMsg} = Timeout, + TimerRefs, TimerTypes, CancelTimers, [], _Seen, TimeoutEvents) -> + {TimerRefs,TimerTypes,CancelTimers,TimeoutEvents}; +parse_timers( + TimerRefs, TimerTypes, CancelTimers, [Timeout|TimeoutsR], + Seen, TimeoutEvents) -> + case Timeout of + {TimerType,Time,TimerMsg} -> + parse_timers( + TimerRefs, TimerTypes, CancelTimers, TimeoutsR, + Seen, TimeoutEvents, + TimerType, Time, TimerMsg); + Time -> + parse_timers( + TimerRefs, TimerTypes, CancelTimers, TimeoutsR, + Seen, TimeoutEvents, + timeout, Time, Time) + end. + +parse_timers( + TimerRefs, TimerTypes, CancelTimers, TimeoutsR, + Seen, TimeoutEvents, + TimerType, Time, TimerMsg) -> case Seen of #{TimerType := _} -> %% Type seen before - ignore parse_timers( - TimerRefs, TimerTypes, TimeoutsR, Seen, TimeoutEvents); + TimerRefs, TimerTypes, CancelTimers, TimeoutsR, + Seen, TimeoutEvents); #{} -> %% Unseen type - handle NewSeen = Seen#{TimerType => true}, - %% Cancel any running timer - {NewTimerRefs,NewTimerTypes} = - cancel_timer_by_type(TimerType, TimerRefs, TimerTypes), - if - Time =:= infinity -> - %% Ignore - timer will never fire + case Time of + infinity -> + %% Cancel any running timer + {NewTimerTypes,NewCancelTimers} = + cancel_timer_by_type( + TimerType, TimerTypes, CancelTimers), parse_timers( - NewTimerRefs, NewTimerTypes, TimeoutsR, + TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, NewSeen, TimeoutEvents); - TimerType =:= timeout -> - %% Handle event timer later - parse_timers( - NewTimerRefs, NewTimerTypes, TimeoutsR, - NewSeen, [Timeout|TimeoutEvents]); - Time =:= 0 -> + 0 -> + %% Cancel any running timer + {NewTimerTypes,NewCancelTimers} = + cancel_timer_by_type( + TimerType, TimerTypes, CancelTimers), %% Handle zero time timeouts later TimeoutEvent = {TimerType,TimerMsg}, parse_timers( - NewTimerRefs, NewTimerTypes, TimeoutsR, + TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, NewSeen, [TimeoutEvent|TimeoutEvents]); - true -> - %% Start a new timer - TimerRef = erlang:start_timer(Time, self(), TimerMsg), - parse_timers( - NewTimerRefs#{TimerRef => TimerType}, - NewTimerTypes#{TimerType => TimerRef}, - 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), + NewCancelTimers = CancelTimers + 1, + %% Insert the new timer into + %% both TimerRefs and TimerTypes + parse_timers( + TimerRefs#{TimerRef => TimerType}, + TimerTypes#{TimerType => TimerRef}, + NewCancelTimers, TimeoutsR, + NewSeen, TimeoutEvents); + #{} -> + parse_timers( + TimerRefs#{TimerRef => TimerType}, + TimerTypes#{TimerType => TimerRef}, + CancelTimers, TimeoutsR, + NewSeen, TimeoutEvents) + end end end. -%% Enqueue immediate timeout events and start event timer -process_timeout_events(TimerRefs, TimerTypes, [], EventsR) -> - {TimerRefs, TimerTypes, EventsR}; -process_timeout_events( - TimerRefs, TimerTypes, - [{timeout,0,TimerMsg}|TimeoutEvents], []) -> - %% No enqueued events - insert a timeout zero event - TimeoutEvent = {timeout,TimerMsg}, - process_timeout_events( - TimerRefs, TimerTypes, - TimeoutEvents, [TimeoutEvent]); -process_timeout_events( - TimerRefs, TimerTypes, - [{timeout,Time,TimerMsg}], []) -> - %% No enqueued events - start event timer - TimerRef = erlang:start_timer(Time, self(), TimerMsg), - process_timeout_events( - TimerRefs#{TimerRef => timeout}, TimerTypes#{timeout => TimerRef}, - [], []); -process_timeout_events( - TimerRefs, TimerTypes, - [{timeout,_Time,_TimerMsg}|TimeoutEvents], EventsR) -> - %% There will be some other event so optimize by not starting - %% an event timer to just have to cancel it again - process_timeout_events( - TimerRefs, TimerTypes, - TimeoutEvents, EventsR); -process_timeout_events( - TimerRefs, TimerTypes, - [{_TimeoutType,_TimeoutMsg} = TimeoutEvent|TimeoutEvents], EventsR) -> - process_timeout_events( - TimerRefs, TimerTypes, - TimeoutEvents, [TimeoutEvent|EventsR]). +%% Enqueue immediate timeout events (timeout 0 events) +%% +%% Event timer timeout 0 events gets special treatment since +%% an event timer is cancelled by any received event, +%% so if there are enqueued events before the event timer +%% timeout 0 event - the event timer is cancelled hence no event. +%% +%% Other (state_timeout) timeout 0 events that are after +%% the event timer timeout 0 events are considered to +%% belong to timers that were started after the event timer +%% timeout 0 event fired, so they do not cancel the event timer. +%% +prepend_timeout_events([], EventsR) -> + EventsR; +prepend_timeout_events([{timeout,_} = TimeoutEvent|TimeoutEvents], []) -> + prepend_timeout_events(TimeoutEvents, [TimeoutEvent]); +prepend_timeout_events([{timeout,_}|TimeoutEvents], EventsR) -> + prepend_timeout_events(TimeoutEvents, EventsR); +prepend_timeout_events([TimeoutEvent|TimeoutEvents], EventsR) -> + %% Just prepend all others + prepend_timeout_events(TimeoutEvents, [TimeoutEvent|EventsR]). @@ -1448,18 +1529,11 @@ process_timeout_events( %% Server helpers reply_then_terminate( - Class, Reason, Stacktrace, - Debug, #{state := State} = S, Q, Replies) -> - if - is_list(Replies) -> - do_reply_then_terminate( - Class, Reason, Stacktrace, - Debug, S, Q, Replies, State); - true -> - do_reply_then_terminate( - Class, Reason, Stacktrace, - Debug, S, Q, [Replies], State) - end. + Class, Reason, Stacktrace, Debug, + #{state := State} = S, Q, Replies) -> + do_reply_then_terminate( + Class, Reason, Stacktrace, Debug, + S, Q, listify(Replies), State). %% do_reply_then_terminate( Class, Reason, Stacktrace, Debug, S, Q, [], _State) -> @@ -1485,21 +1559,25 @@ do_reply(Debug, S, State, From, Reply) -> terminate( - Class, Reason, Stacktrace, - Debug, + Class, Reason, Stacktrace, Debug, #{module := Module, state := State, data := Data, postponed := P} = S, Q) -> - try Module:terminate(Reason, State, Data) of - _ -> ok - catch - _ -> ok; - C:R -> - ST = erlang:get_stacktrace(), - error_info( - C, R, ST, S, Q, P, - format_status(terminate, get(), S)), - sys:print_log(Debug), - erlang:raise(C, R, ST) + case erlang:function_exported(Module, terminate, 3) of + true -> + try Module:terminate(Reason, State, Data) of + _ -> ok + catch + _ -> ok; + C:R -> + ST = erlang:get_stacktrace(), + error_info( + C, R, ST, S, Q, P, + format_status(terminate, get(), S)), + sys:print_log(Debug), + erlang:raise(C, R, ST) + end; + false -> + ok end, _ = case Reason of @@ -1637,28 +1715,21 @@ listify(Item) -> [Item]. %% Cancel timer if running, otherwise no op -cancel_timer_by_type(TimerType, TimerRefs, TimerTypes) -> +%% +%% This is an asynchronous cancel so the timer is not really cancelled +%% until we get a cancel_timer msg i.e {cancel_timer,TimerRef,_}. +%% In the mean time we might get a timeout message. +%% +%% Remove the timer from TimerTypes. +%% When we get the cancel_timer msg we remove it from TimerRefs. +cancel_timer_by_type(TimerType, TimerTypes, CancelTimers) -> case TimerTypes of #{TimerType := TimerRef} -> cancel_timer(TimerRef), - {maps:remove(TimerRef, TimerRefs), - maps:remove(TimerType, TimerTypes)}; + {maps:remove(TimerType, TimerTypes),CancelTimers + 1}; #{} -> - {TimerRefs,TimerTypes} + {TimerTypes,CancelTimers} end. -%%cancel_timer(undefined) -> -%% ok; -cancel_timer(TRef) -> - case erlang:cancel_timer(TRef) of - false -> - %% We have to assume that TRef is the ref of a running timer - %% and if so the timer has expired - %% hence we must wait for the timeout message - receive - {timeout,TRef,_} -> - ok - end; - _TimeLeft -> - ok - end. +cancel_timer(TimerRef) -> + ok = erlang:cancel_timer(TimerRef, [{async,true}]). diff --git a/lib/stdlib/test/gen_statem_SUITE.erl b/lib/stdlib/test/gen_statem_SUITE.erl index 8f2ba0cab2..ac27c9fc79 100644 --- a/lib/stdlib/test/gen_statem_SUITE.erl +++ b/lib/stdlib/test/gen_statem_SUITE.erl @@ -38,7 +38,7 @@ all() -> {group, abnormal}, {group, abnormal_handle_event}, shutdown, stop_and_reply, state_enter, event_order, - state_timeout, code_change, + state_timeout, event_types, code_change, {group, sys}, hibernate, enter_loop]. @@ -600,15 +600,26 @@ state_enter(_Config) -> (internal, Prev, N) -> Self ! {internal,start,Prev,N}, {keep_state,N + 1}; + ({call,From}, repeat, N) -> + {repeat_state,N + 1, + [{reply,From,{repeat,start,N}}]}; ({call,From}, echo, N) -> - {next_state,wait,N + 1,{reply,From,{echo,start,N}}}; + {next_state,wait,N + 1, + {reply,From,{echo,start,N}}}; ({call,From}, {stop,Reason}, N) -> - {stop_and_reply,Reason,[{reply,From,{stop,N}}],N + 1} + {stop_and_reply,Reason, + [{reply,From,{stop,N}}],N + 1} end, wait => - fun (enter, Prev, N) -> + fun (enter, Prev, N) when N < 5 -> + {repeat_state,N + 1, + {reply,{Self,N},{enter,Prev}}}; + (enter, Prev, N) -> Self ! {enter,wait,Prev,N}, {keep_state,N + 1}; + ({call,From}, repeat, N) -> + {repeat_state_and_data, + [{reply,From,{repeat,wait,N}}]}; ({call,From}, echo, N) -> {next_state,start,N + 1, [{next_event,internal,wait}, @@ -620,11 +631,15 @@ state_enter(_Config) -> [{enter,start,start,1}] = flush(), {echo,start,2} = gen_statem:call(STM, echo), - [{enter,wait,start,3}] = flush(), - {wait,[4|_]} = sys:get_state(STM), - {echo,wait,4} = gen_statem:call(STM, echo), - [{enter,start,wait,5},{internal,start,wait,6}] = flush(), - {stop,7} = gen_statem:call(STM, {stop,bye}), + [{3,{enter,start}},{4,{enter,start}},{enter,wait,start,5}] = flush(), + {wait,[6|_]} = sys:get_state(STM), + {repeat,wait,6} = gen_statem:call(STM, repeat), + [{enter,wait,wait,6}] = flush(), + {echo,wait,7} = gen_statem:call(STM, echo), + [{enter,start,wait,8},{internal,start,wait,9}] = flush(), + {repeat,start,10} = gen_statem:call(STM, repeat), + [{enter,start,start,11}] = flush(), + {stop,12} = gen_statem:call(STM, {stop,bye}), [{'EXIT',STM,bye}] = flush(), {noproc,_} = @@ -801,6 +816,74 @@ state_timeout(_Config) -> +%% Test that all event types can be sent with {next_event,EventType,_} +event_types(_Config) -> + process_flag(trap_exit, true), + + Machine = + %% Abusing the internal format of From... + #{init => + fun () -> + {ok, start, undefined} + end, + start => + fun ({call,_} = Call, Req, undefined) -> + {next_state, state1, undefined, + [{next_event,internal,1}, + {next_event,state_timeout,2}, + {next_event,timeout,3}, + {next_event,info,4}, + {next_event,cast,5}, + {next_event,Call,Req}]} + end, + state1 => + fun (internal, 1, undefined) -> + {next_state, state2, undefined} + end, + state2 => + fun (state_timeout, 2, undefined) -> + {next_state, state3, undefined} + end, + state3 => + fun (timeout, 3, undefined) -> + {next_state, state4, undefined} + end, + state4 => + fun (info, 4, undefined) -> + {next_state, state5, undefined} + end, + state5 => + fun (cast, 5, undefined) -> + {next_state, state6, undefined} + end, + state6 => + fun ({call,From}, stop, undefined) -> + {stop_and_reply, shutdown, + [{reply,From,stopped}]} + end}, + {ok,STM} = + gen_statem:start_link( + ?MODULE, {map_statem,Machine,[]}, [{debug,[trace]}]), + + stopped = gen_statem:call(STM, stop), + receive + {'EXIT',STM,shutdown} -> + ok + after 500 -> + ct:fail(did_not_stop) + end, + + {noproc,_} = + ?EXPECT_FAILURE(gen_statem:call(STM, hej), Reason), + case flush() of + [] -> + ok; + Other2 -> + ct:fail({unexpected,Other2}) + end. + + + sys1(Config) -> {ok,Pid} = gen_statem:start(?MODULE, start_arg(Config, []), []), {status, Pid, {module,gen_statem}, _} = sys:get_status(Pid), @@ -1722,6 +1805,10 @@ handle_event( {keep_state,[NewData|Machine]}; {keep_state,NewData,Ops} -> {keep_state,[NewData|Machine],Ops}; + {repeat_state,NewData} -> + {repeat_state,[NewData|Machine]}; + {repeat_state,NewData,Ops} -> + {repeat_state,[NewData|Machine],Ops}; Other -> Other end; diff --git a/lib/tools/emacs/erlang-skels.el b/lib/tools/emacs/erlang-skels.el index eeba7f34e9..bdb3d9ad4a 100644 --- a/lib/tools/emacs/erlang-skels.el +++ b/lib/tools/emacs/erlang-skels.el @@ -1,7 +1,7 @@ ;; ;; %CopyrightBegin% ;; -;; Copyright Ericsson AB 2010-2016. All Rights Reserved. +;; Copyright Ericsson AB 2010-2017. All Rights Reserved. ;; ;; Licensed under the Apache License, Version 2.0 (the "License"); ;; you may not use this file except in compliance with the License. @@ -915,11 +915,7 @@ Please see the function `tempo-define-template'.") "%% process to initialize." n (erlang-skel-separator-end 2) "-spec init(Args :: term()) ->" n> - "{ok, State :: term(), Data :: term()} |" n> - "{ok, State :: term(), Data :: term()," n> - "[gen_statem:action()] | gen_statem:action()} |" n> - "ignore |" n> - "{stop, Reason :: term()}." n + "gen_statem:init_result(atom())." n "init([]) ->" n> "process_flag(trap_exit, true)," n> "{ok, state_name, #data{}}." n @@ -1028,11 +1024,7 @@ Please see the function `tempo-define-template'.") "%% process to initialize." n (erlang-skel-separator-end 2) "-spec init(Args :: term()) ->" n> - "{ok, State :: term(), Data :: term()} |" n> - "{ok, State :: term(), Data :: term()," n> - "[gen_statem:action()] | gen_statem:action()} |" n> - "ignore |" n> - "{stop, Reason :: term()}." n + "gen_statem:init_result(term())." n "init([]) ->" n> "process_flag(trap_exit, true)," n> "{ok, state_name, #data{}}." n diff --git a/system/doc/design_principles/statem.xml b/system/doc/design_principles/statem.xml index d08ddd0036..f4d84ab163 100644 --- a/system/doc/design_principles/statem.xml +++ b/system/doc/design_principles/statem.xml @@ -1180,6 +1180,17 @@ open(state_timeout, lock, Data) -> {next_state, locked, Data}; ... ]]></code> + <p> + You can repeat the state entry code by returning one of + <c>{repeat_state, ...}</c>, <c>{repeat_state_and_data,_}</c> + or <c>repeat_state_and_data</c> that otherwise behaves + exactly like their <c>keep_state</c> siblings. + See the type + <seealso marker="stdlib:gen_statem#type-state_callback_result"> + <c>state_callback_result()</c> + </seealso> + in the reference manual. + </p> </section> <!-- =================================================================== --> |