diff options
Diffstat (limited to 'lib/stdlib/src/gen_statem.erl')
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 1537 |
1 files changed, 982 insertions, 555 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index 23bddafeed..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. @@ -24,7 +24,7 @@ [start/3,start/4,start_link/3,start_link/4, stop/1,stop/3, cast/2,call/2,call/3, - enter_loop/5,enter_loop/6,enter_loop/7, + enter_loop/4,enter_loop/5,enter_loop/6, reply/1,reply/2]). %% gen callbacks @@ -44,15 +44,22 @@ -export( [wakeup_from_hibernate/3]). -%% Type exports for templates +%% Type exports for templates and callback modules -export_type( [event_type/0, - callback_mode/0, - state_function_result/0, - handle_event_result/0, + callback_mode_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]). -%% Fix problem for doc build +%% Type that is exported just to be documented -export_type([transition_option/0]). %%%========================================================================== @@ -63,8 +70,8 @@ {To :: pid(), Tag :: term()}. % Reply-to specifier for call -type state() :: - state_name() | % For state callback function StateName/5 - term(). % For state callback function handle_event/5 + state_name() | % For StateName/3 callback functions + term(). % For handle_event/4 callback function -type state_name() :: atom(). @@ -72,12 +79,16 @@ -type event_type() :: {'call',From :: from()} | 'cast' | - 'info' | 'timeout' | 'internal'. + 'info' | 'timeout' | 'state_timeout' | 'internal'. +-type callback_mode_result() :: + callback_mode() | [callback_mode() | state_enter()]. -type callback_mode() :: 'state_functions' | 'handle_event_function'. +-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 (=/=) @@ -89,6 +100,10 @@ %% Generate a ('timeout', EventContent, ...) event after Time %% unless some other event is delivered Time :: timeout(). +-type state_timeout() :: + %% Generate a ('state_timeout', EventContent, ...) event after Time + %% unless the state is changed + Time :: timeout(). -type action() :: %% During a state change: @@ -96,7 +111,7 @@ %% * 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') @@ -108,100 +123,137 @@ 'postpone' | % Set the postpone option {'postpone', Postpone :: postpone()} | %% + %% All 'next_event' events are kept in a list and then + %% inserted at state changes so the first in the + %% action() list is the first to be delivered. + {'next_event', % Insert event as the next to handle + EventType :: event_type(), + EventContent :: term()} | + enter_action(). +-type enter_action() :: 'hibernate' | % Set the hibernate option {'hibernate', Hibernate :: hibernate()} | %% (Timeout :: event_timeout()) | % {timeout,Timeout} - {'timeout', % Set the event timeout option + {'timeout', % Set the event_timeout option Time :: event_timeout(), EventContent :: term()} | + {'state_timeout', % Set the state_timeout option + Time :: state_timeout(), EventContent :: term()} | %% - reply_action() | - %% - %% All 'next_event' events are kept in a list and then - %% inserted at state changes so the first in the - %% action() list is the first to be delivered. - {'next_event', % Insert event as the next to handle - EventType :: event_type(), - EventContent :: term()}. + reply_action(). -type reply_action() :: {'reply', % Reply to a caller From :: from(), Reply :: term()}. +-type init_result(StateType) :: + {ok, State :: StateType, Data :: data()} | + {ok, State :: StateType, Data :: data(), + Actions :: [action()] | action()} | + 'ignore' | + {'stop', Reason :: term()}. + +%% Old, not advertised -type state_function_result() :: - {'next_state', % {next_state,NextStateName,NewData,[]} - NextStateName :: state_name(), + event_handler_result(state_name()). +-type handle_event_result() :: + event_handler_result(state()). +%% +-type state_enter_result(State) :: + {'next_state', % {next_state,NextState,NewData,[]} + State, NewData :: data()} | {'next_state', % State transition, maybe to the same state - NextStateName :: state_name(), + State, NewData :: data(), - Actions :: [action()] | action()} | - common_state_callback_result(). --type handle_event_result() :: + Actions :: [enter_action()] | enter_action()} | + state_callback_result(enter_action()). +-type event_handler_result(StateType) :: {'next_state', % {next_state,NextState,NewData,[]} - NextState :: state(), + NextState :: StateType, NewData :: data()} | {'next_state', % State transition, maybe to the same state - NextState :: state(), + NextState :: StateType, NewData :: data(), Actions :: [action()] | action()} | - common_state_callback_result(). --type common_state_callback_result() :: + state_callback_result(action()). +-type state_callback_result(ActionType) :: + {'keep_state', % {keep_state,NewData,[]} + NewData :: data()} | + {'keep_state', % Keep state, change data + NewData :: data(), + Actions :: [ActionType] | ActionType} | + '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()} | {'stop_and_reply', % Reply then stop the server Reason :: term(), Replies :: [reply_action()] | reply_action(), - NewData :: data()} | - {'keep_state', % {keep_state,NewData,[]} - NewData :: data()} | - {'keep_state', % Keep state, change data - NewData :: data(), - Actions :: [action()] | action()} | - 'keep_state_and_data' | % {keep_state_and_data,[]} - {'keep_state_and_data', % Keep state and data -> only actions - Actions :: [action()] | action()}. + NewData :: data()}. %% The state machine init function. It is called only once and %% 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()) -> - {callback_mode(), state(), data()} | - {callback_mode(), state(), data(), [action()] | action()} | - 'ignore' | - {'stop', Reason :: term()}. +-callback init(Args :: term()) -> init_result(state()). + +%% This callback shall return the callback mode of the callback module. +%% +%% It is called once after init/0 and code_change/4 but before +%% the first state callback StateName/3 or handle_event/4. +-callback callback_mode() -> callback_mode_result(). -%% Example state callback for callback_mode() =:= state_functions -%% state name 'state_name'. +%% Example state callback for StateName = 'state_name' +%% when callback_mode() =:= state_functions. %% -%% In this mode all states has to be type state_name() i.e atom(). +%% In this mode all states has to be of type state_name() i.e atom(). %% -%% Note that state callbacks and only state callbacks have arity 5 -%% and that is intended. +%% Note that the only callbacks that have arity 3 are these +%% StateName/3 callbacks and terminate/3, so the state name +%% 'terminate' is unusable in this mode. -callback state_name( - event_type(), + 'enter', + OldStateName :: state_name(), + Data :: data()) -> + state_enter_result('state_name'); + (event_type(), EventContent :: term(), Data :: data()) -> - state_function_result(). + event_handler_result(state_name()). %% -%% State callback for callback_mode() =:= handle_event_function. -%% -%% Note that state callbacks and only state callbacks have arity 5 -%% and that is intended. +%% State callback for all states +%% when callback_mode() =:= handle_event_function. -callback handle_event( - event_type(), + 'enter', + OldState :: state(), + State, % Current state + Data :: data()) -> + state_enter_result(State); + (event_type(), EventContent :: term(), State :: state(), % Current state Data :: data()) -> - handle_event_result(). + event_handler_result(state()). %% Clean up before the server terminates. -callback terminate( @@ -219,9 +271,8 @@ OldState :: state(), OldData :: data(), Extra :: term()) -> - {NewCallbackMode :: callback_mode(), - NewState :: state(), - NewData :: data()}. + {ok, NewState :: state(), NewData :: data()} | + (Reason :: term()). %% Format the callback module state in some sensible that is %% often condensed way. For StatusOption =:= 'normal' the perferred @@ -238,11 +289,16 @@ -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/5 callback function for every StateName. + state_name/3, % Example for callback_mode() =:= state_functions: + %% there has to be a StateName/3 callback function + %% for every StateName in your state machine but the state name + %% 'state_name' does of course not have to be used. %% - handle_event/4]). % For callback_mode =:= handle_event_function + handle_event/4 % For callback_mode() =:= handle_event_function + ]). %% Type validation functions callback_mode(CallbackMode) -> @@ -264,12 +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; _ -> @@ -378,53 +438,79 @@ call(ServerRef, Request) -> -spec call( ServerRef :: server_ref(), Request :: term(), - Timeout :: timeout()) -> + Timeout :: + timeout() | + {'clean_timeout',T :: timeout()} | + {'dirty_timeout',T :: timeout()}) -> Reply :: term(). -call(ServerRef, Request, infinity) -> - try gen:call(ServerRef, '$gen_call', Request, infinity) of - {ok,Reply} -> - Reply - catch - Class:Reason -> - erlang:raise( - Class, - {Reason,{?MODULE,call,[ServerRef,Request,infinity]}}, - erlang:get_stacktrace()) - end; call(ServerRef, Request, Timeout) -> - %% Call server through proxy process to dodge any late reply - Ref = make_ref(), - Self = self(), - Pid = spawn( - fun () -> - Self ! - try gen:call( - ServerRef, '$gen_call', Request, Timeout) of - Result -> - {Ref,Result} - catch Class:Reason -> - {Ref,Class,Reason,erlang:get_stacktrace()} - end - end), - Mref = monitor(process, Pid), - receive - {Ref,Result} -> - demonitor(Mref, [flush]), - case Result of + case parse_timeout(Timeout) of + {dirty_timeout,T} -> + try gen:call(ServerRef, '$gen_call', Request, T) of {ok,Reply} -> Reply + catch + Class:Reason -> + erlang:raise( + Class, + {Reason,{?MODULE,call,[ServerRef,Request,Timeout]}}, + erlang:get_stacktrace()) + end; + {clean_timeout,T} -> + %% Call server through proxy process to dodge any late reply + Ref = make_ref(), + Self = self(), + Pid = spawn( + fun () -> + Self ! + try gen:call( + ServerRef, '$gen_call', Request, T) of + Result -> + {Ref,Result} + catch Class:Reason -> + {Ref,Class,Reason, + erlang:get_stacktrace()} + end + end), + Mref = monitor(process, Pid), + receive + {Ref,Result} -> + demonitor(Mref, [flush]), + case Result of + {ok,Reply} -> + Reply + end; + {Ref,Class,Reason,Stacktrace} -> + demonitor(Mref, [flush]), + erlang:raise( + Class, + {Reason,{?MODULE,call,[ServerRef,Request,Timeout]}}, + Stacktrace); + {'DOWN',Mref,_,_,Reason} -> + %% There is a theoretical possibility that the + %% proxy process gets killed between try--of and ! + %% so this clause is in case of that + exit(Reason) end; - {Ref,Class,Reason,Stacktrace} -> - demonitor(Mref, [flush]), - erlang:raise( - Class, - {Reason,{?MODULE,call,[ServerRef,Request,Timeout]}}, - Stacktrace); - {'DOWN',Mref,_,_,Reason} -> - %% There is a theoretical possibility that the - %% proxy process gets killed between try--of and ! - %% so this clause is in case of that - exit(Reason) + Error when is_atom(Error) -> + erlang:error(Error, [ServerRef,Request,Timeout]) + end. + +parse_timeout(Timeout) -> + case Timeout of + {clean_timeout,infinity} -> + {dirty_timeout,infinity}; + {clean_timeout,_} -> + Timeout; + {dirty_timeout,_} -> + Timeout; + {_,_} -> + %% Be nice and throw a badarg for speling errors + badarg; + infinity -> + {dirty_timeout,infinity}; + T -> + {clean_timeout,T} end. %% Reply from a state machine callback to whom awaits in call/2 @@ -450,43 +536,35 @@ reply({To,Tag}, Reply) when is_pid(To) -> %% the same arguments as you would have returned from init/1 -spec enter_loop( Module :: module(), Opts :: [debug_opt()], - CallbackMode :: callback_mode(), State :: state(), Data :: data()) -> no_return(). -enter_loop(Module, Opts, CallbackMode, State, Data) -> - enter_loop(Module, Opts, CallbackMode, State, Data, self()). +enter_loop(Module, Opts, State, Data) -> + enter_loop(Module, Opts, State, Data, self()). %% -spec enter_loop( Module :: module(), Opts :: [debug_opt()], - CallbackMode :: callback_mode(), State :: state(), Data :: data(), Server_or_Actions :: server_name() | pid() | [action()]) -> no_return(). -enter_loop(Module, Opts, CallbackMode, State, Data, Server_or_Actions) -> +enter_loop(Module, Opts, State, Data, Server_or_Actions) -> if is_list(Server_or_Actions) -> - enter_loop( - Module, Opts, CallbackMode, State, Data, - self(), Server_or_Actions); + enter_loop(Module, Opts, State, Data, self(), Server_or_Actions); true -> - enter_loop( - Module, Opts, CallbackMode, State, Data, - Server_or_Actions, []) + enter_loop(Module, Opts, State, Data, Server_or_Actions, []) end. %% -spec enter_loop( Module :: module(), Opts :: [debug_opt()], - CallbackMode :: callback_mode(), State :: state(), Data :: data(), Server :: server_name() | pid(), Actions :: [action()] | action()) -> no_return(). -enter_loop(Module, Opts, CallbackMode, State, Data, Server, Actions) -> +enter_loop(Module, Opts, State, Data, Server, Actions) -> is_atom(Module) orelse error({atom,Module}), - callback_mode(CallbackMode) orelse error({callback_mode,CallbackMode}), Parent = gen:get_parent(), - enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent). + enter(Module, Opts, State, Data, Server, Actions, Parent). %%--------------------------------------------------------------------------- %% API helpers @@ -514,12 +592,13 @@ send(Proc, Msg) -> end. %% Here the init_it/6 and enter_loop/5,6,7 functions converge -enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) -> +enter(Module, Opts, State, Data, Server, Actions, Parent) -> %% The values should already have been type checked Name = gen:get_proc_name(Server), Debug = gen:debug_options(Name, Opts), - P = Events = [], - Event = {internal,initial_state}, + Events = [], + P = [], + Event = {internal,init_state}, %% We enforce {postpone,false} to ensure that %% our fake Event gets discarded, thought it might get logged NewActions = @@ -529,21 +608,50 @@ enter(Module, Opts, CallbackMode, 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 => CallbackMode, + callback_mode => undefined, + state_enter => false, module => Module, name => Name, - %% All fields below will be replaced according to the arguments to - %% loop_event_actions/10 when it finally loops back to loop/3 state => State, data => Data, postponed => P, - hibernate => false, - timer => undefined}, + %% + %% 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}), - loop_event_actions( - Parent, NewDebug, S, Events, - State, Data, P, Event, State, NewActions). + case call_callback_mode(S) of + {ok,NewS} -> + loop_event_actions( + Parent, NewDebug, NewS, + Events, Event, State, Data, NewActions, true); + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, NewDebug, + S, [Event|Events]) + end. %%%========================================================================== %%% gen callbacks @@ -558,9 +666,17 @@ init_it(Starter, Parent, ServerRef, Module, Args, Opts) -> Result -> init_result(Starter, Parent, ServerRef, Module, Result, Opts); Class:Reason -> + Stacktrace = erlang:get_stacktrace(), + Name = gen:get_proc_name(ServerRef), gen:unregister_name(ServerRef), proc_lib:init_ack(Starter, {error,Reason}), - erlang:raise(Class, Reason, erlang:get_stacktrace()) + error_info( + Class, Reason, Stacktrace, + #{name => Name, + callback_mode => undefined, + state_enter => false}, + [], [], undefined), + erlang:raise(Class, Reason, Stacktrace) end. %%--------------------------------------------------------------------------- @@ -568,30 +684,12 @@ init_it(Starter, Parent, ServerRef, Module, Args, Opts) -> init_result(Starter, Parent, ServerRef, Module, Result, Opts) -> case Result of - {CallbackMode,State,Data} -> - case callback_mode(CallbackMode) of - true -> - proc_lib:init_ack(Starter, {ok,self()}), - enter( - Module, Opts, CallbackMode, State, Data, - ServerRef, [], Parent); - false -> - Error = {callback_mode,CallbackMode}, - proc_lib:init_ack(Starter, {error,Error}), - exit(Error) - end; - {CallbackMode,State,Data,Actions} -> - case callback_mode(CallbackMode) of - true -> - proc_lib:init_ack(Starter, {ok,self()}), - enter( - Module, Opts, CallbackMode, State, Data, - ServerRef, Actions, Parent); - false -> - Error = {callback_mode,CallbackMode}, - proc_lib:init_ack(Starter, {error,Error}), - exit(Error) - end; + {ok,State,Data} -> + proc_lib:init_ack(Starter, {ok,self()}), + enter(Module, Opts, State, Data, ServerRef, [], Parent); + {ok,State,Data,Actions} -> + proc_lib:init_ack(Starter, {ok,self()}), + enter(Module, Opts, State, Data, ServerRef, Actions, Parent); {stop,Reason} -> gen:unregister_name(ServerRef), proc_lib:init_ack(Starter, {error,Reason}), @@ -601,8 +699,16 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) -> proc_lib:init_ack(Starter, ignore), exit(normal); _ -> - Error = {bad_return_value,Result}, + Name = gen:get_proc_name(ServerRef), + gen:unregister_name(ServerRef), + Error = {bad_return_from_init,Result}, proc_lib:init_ack(Starter, {error,Error}), + error_info( + error, Error, ?STACKTRACE(), + #{name => Name, + callback_mode => undefined, + state_enter => false}, + [], [], undefined), exit(Error) end. @@ -612,12 +718,8 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) -> system_continue(Parent, Debug, S) -> loop(Parent, Debug, S). -system_terminate( - Reason, _Parent, Debug, - #{state := State, data := Data, postponed := P} = S) -> - terminate( - exit, Reason, ?STACKTRACE(), - Debug, S, [], State, Data, P). +system_terminate(Reason, _Parent, Debug, S) -> + terminate(exit, Reason, ?STACKTRACE(), Debug, S, []). system_code_change( #{module := Module, @@ -630,11 +732,9 @@ system_code_change( Result -> Result end of - {NewCallbackMode,NewState,NewData} -> - callback_mode(NewCallbackMode) orelse - error({callback_mode,NewCallbackMode}), + {ok,NewState,NewData} -> {ok, - S#{callback_mode := NewCallbackMode, + S#{callback_mode := undefined, state := NewState, data := NewData}}; {ok,_} = Error -> @@ -656,7 +756,7 @@ system_replace_state( format_status( Opt, [PDict,SysState,Parent,Debug, - #{name := Name, postponed := P, state := State, data := Data} = S]) -> + #{name := Name, postponed := P} = S]) -> Header = gen:format_status_header("Status for state machine", Name), Log = sys:get_debug(log, Debug, []), [{header,Header}, @@ -665,7 +765,7 @@ format_status( {"Parent",Parent}, {"Logged Events",Log}, {"Postponed",P}]} | - case format_status(Opt, PDict, S, State, Data) of + case format_status(Opt, PDict, S) of L when is_list(L) -> L; T -> [T] end]. @@ -675,14 +775,18 @@ format_status( %% them, not as the real erlang messages. Use trace for that. %%--------------------------------------------------------------------------- -print_event(Dev, {in,Event}, {Name,_}) -> +print_event(Dev, {in,Event}, {Name,State}) -> + io:format( + Dev, "*DBG* ~p receive ~s in state ~p~n", + [Name,event_string(Event),State]); +print_event(Dev, {out,Reply,{To,_Tag}}, {Name,State}) -> io:format( - Dev, "*DBG* ~p received ~s~n", - [Name,event_string(Event)]); -print_event(Dev, {out,Reply,{To,_Tag}}, {Name,_}) -> + Dev, "*DBG* ~p send ~p to ~p from state ~p~n", + [Name,Reply,To,State]); +print_event(Dev, {terminate,Reason}, {Name,State}) -> io:format( - Dev, "*DBG* ~p sent ~p to ~p~n", - [Name,Reply,To]); + Dev, "*DBG* ~p terminate ~p in state ~p~n", + [Name,Reason,State]); print_event(Dev, {Tag,Event,NextState}, {Name,State}) -> StateString = case NextState of @@ -726,22 +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 := Timer} = S) -> +loop_receive(Parent, Debug, S) -> receive Msg -> case Msg of @@ -750,36 +854,87 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) -> %% Does not return but tail recursively calls %% system_continue/3 that jumps to loop/3 sys:handle_system_msg( - Req, Pid, Parent, ?MODULE, Debug, S, Hibernate); + Req, Pid, Parent, ?MODULE, Debug, S, + Hibernate); {'EXIT',Parent,Reason} = EXIT -> - #{state := State, data := Data, postponed := P} = S, - %% 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], State, Data, P); - {timeout,Timer,Content} when Timer =/= undefined -> - loop_receive_result( - Parent, Debug, S, {timeout,Content}); - _ -> - %% Cancel Timer if running - case Timer of - undefined -> - ok; + %% EXIT is not a 2-tuple therefore + %% not an event but this will stand out + %% in the crash report... + Q = [EXIT], + terminate(exit, Reason, ?STACKTRACE(), Debug, S, Q); + {timeout,TimerRef,TimerMsg} -> + #{timer_refs := TimerRefs, + timer_types := TimerTypes, + hibernate := Hibernate} = S, + case TimerRefs of + #{TimerRef := TimerType} -> + %% We know of this timer; is it a running + %% timer or a timer being cancelled 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, 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; _ -> - case erlang:cancel_timer(Timer) of - TimeLeft when is_integer(TimeLeft) -> - ok; - false -> - receive - {timeout,Timer,_} -> - ok - after 0 -> - ok - end - end - end, + %% Not our cancel_timer msg; + %% present it as an event + Event = {info,Msg}, + loop_receive_result( + Parent, Debug, S, Hibernate, Event) + end; + _ -> + %% External msg + #{hibernate := Hibernate} = S, Event = case Msg of {'$gen_call',From,Request} -> @@ -789,388 +944,613 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) -> _ -> {info,Msg} end, - loop_receive_result(Parent, Debug, S, Event) + loop_receive_result( + Parent, Debug, S, Hibernate, Event) end end. loop_receive_result( Parent, Debug, #{state := State, - data := Data, - postponed := P} = S, - Event) -> - %% The engine state map S is now dismantled - %% and will not be restored until we return to loop/3. - %% - %% The fields 'callback_mode', 'module', and 'name' are still valid. - %% The fields 'state', 'data', and 'postponed' are held in arguments. - %% The fields 'timer' and 'hibernate' will be recalculated. - %% + 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, Events, State, Data, P, 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, [Event|Events], - State, Data, P, Hibernate, _Timeout) -> - %% - %% If there was a state timer requested we just ignore that - %% since we have events to handle which cancels the timer - loop_event( - Parent, Debug, S, Events, State, Data, P, Event, Hibernate); -loop_events( - Parent, Debug, S, [], - State, Data, P, Hibernate, Timeout) -> - case Timeout of - {timeout,0,EventContent} -> - %% Immediate timeout - simulate it - %% so we do not get the timeout message - %% after any received event - loop_event( - Parent, Debug, S, [], - State, Data, P, {timeout,EventContent}, Hibernate); - {timeout,Time,EventContent} -> - %% Actually start a timer - Timer = erlang:start_timer(Time, self(), EventContent), - loop_events_done( - Parent, Debug, S, Timer, State, Data, P, Hibernate); - undefined -> - %% No state timeout has been requested - Timer = undefined, - loop_events_done( - Parent, Debug, S, Timer, State, Data, P, 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. -%% -loop_events_done(Parent, Debug, S, Timer, State, Data, P, Hibernate) -> - NewS = - S#{ - state := State, - data := Data, - postponed := P, - hibernate := Hibernate, - timer := Timer}, - loop(Parent, Debug, NewS). +%% Entry point for handling an event, received or enqueued loop_event( Parent, Debug, - #{callback_mode := CallbackMode, - module := Module} = S, - Events, - State, Data, P, {Type,Content} = Event, Hibernate) -> + #{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 - %% might depend on i.e collect garbage which + %% 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} -> + {NextState,NewData,Actions,EnterCall} = + parse_event_result( + true, Debug, NewS, + Events, Event, State, Data, Result), + loop_event_actions( + Parent, Debug, NewS, + Events, Event, NextState, NewData, Actions, EnterCall); + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, Debug, S, + [Event|Events]) + end. + +loop_event_actions( + Parent, Debug, + #{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, EnterCall -> + loop_event_enter( + Parent, NewDebug, S, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR); + true -> + loop_event_result( + Parent, NewDebug, S, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR) + end; + {Class,Reason,Stacktrace} -> + terminate( + Class, Reason, Stacktrace, Debug, S, + [Event|Events]) + end. + +loop_event_enter( + 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} -> + 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, + hibernate := Hibernate}, + [Event|Events]) + end. + +loop_event_enter_actions( + Parent, Debug, #{state_enter := StateEnter} = S, + Events, Event, NextState, NewData, + Hibernate, TimeoutsR, Postpone, NextEventsR, + Actions, EnterCall) -> + case + parse_enter_actions( + Debug, S, NextState, Actions, Hibernate, TimeoutsR) + of + {ok,NewDebug,NewHibernate,NewTimeoutsR,_,_} -> + 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, + hibernate := Hibernate}, + [Event|Events]) + end. + +loop_event_result( + 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. + %% + {Debug_1,P_1} = % Move current event to postponed if Postpone + case Postpone of + true -> + {sys_debug(Debug_0, S_0, State, {postpone,Event_0,State}), + [Event_0|P_0]}; + false -> + {sys_debug(Debug_0, S_0, State, {consume,Event_0,State}), + P_0} + end, + {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_0,P_1,{TimerTypes_0,CancelTimers_0}}; + true -> + {lists:reverse(P_1, Events_0), + [], + cancel_timer_by_type( + state_timeout, TimerTypes_0, CancelTimers_0)} + %% The state timer is removed from TimerTypes_1 + %% but remains in TimerRefs_0 until we get + %% the cancel_timer msg + end, + {TimerRefs_2,TimerTypes_2,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 + 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. + + +%%--------------------------------------------------------------------------- +%% Server loop helpers + +call_callback_mode(#{module := Module} = S) -> + try Module:callback_mode() of + CallbackMode -> + callback_mode_result(S, CallbackMode) + catch + CallbackMode -> + callback_mode_result(S, CallbackMode); + Class:Reason -> + {Class,Reason,erlang:get_stacktrace()} + end. + +callback_mode_result(S, CallbackMode) -> + case + parse_callback_mode( + if + is_atom(CallbackMode) -> + [CallbackMode]; + true -> + CallbackMode + end, undefined, false) + of + {undefined,_} -> + {error, + {bad_return_from_callback_mode,CallbackMode}, + ?STACKTRACE()}; + {CBMode,StateEnter} -> + {ok, + S#{ + callback_mode := CBMode, + state_enter := StateEnter}} + end. + +parse_callback_mode([], CBMode, StateEnter) -> + {CBMode,StateEnter}; +parse_callback_mode([H|T], CBMode, StateEnter) -> + case callback_mode(H) of + true -> + parse_callback_mode(T, H, StateEnter); + false -> + case H of + state_enter -> + parse_callback_mode(T, CBMode, true); + _ -> + {undefined,StateEnter} + end + end; +parse_callback_mode(_, _CBMode, StateEnter) -> + {undefined,StateEnter}. + + +call_state_function( + #{callback_mode := undefined} = S, Type, Content, State, Data) -> + case call_callback_mode(S) of + {ok,NewS} -> + call_state_function(NewS, Type, Content, State, Data); + Error -> + Error + end; +call_state_function( + #{callback_mode := CallbackMode, module := Module} = S, + Type, Content, State, Data) -> try case CallbackMode of state_functions -> Module:State(Type, Content, Data); handle_event_function -> Module:handle_event(Type, Content, State, Data) - end of + end + of Result -> - loop_event_result( - Parent, Debug, S, Events, State, Data, P, Event, Result) + {ok,Result,S} catch Result -> - loop_event_result( - Parent, Debug, S, Events, State, Data, P, Event, Result); - error:badarg when CallbackMode =:= state_functions -> - case erlang:get_stacktrace() of - [{erlang,apply,[Module,State,_],_}|Stacktrace] -> - Args = [Type,Content,Data], - terminate( - error, - {undef_state_function,{Module,State,Args}}, - Stacktrace, - Debug, S, [Event|Events], State, Data, P); - Stacktrace -> - terminate( - error, badarg, Stacktrace, - Debug, S, [Event|Events], State, Data, P) - end; - error:undef -> - %% Process an undef to check for the simple mistake - %% of calling a nonexistent state function - case erlang:get_stacktrace() of - [{Module,State, - [Type,Content,Data]=Args, - _} - |Stacktrace] - when CallbackMode =:= state_functions -> - terminate( - error, - {undef_state_function,{Module,State,Args}}, - Stacktrace, - Debug, S, [Event|Events], State, Data, P); - [{Module,handle_event, - [Type,Content,State,Data]=Args, - _} - |Stacktrace] - when CallbackMode =:= handle_event_function -> - terminate( - error, - {undef_state_function,{Module,handle_event,Args}}, - Stacktrace, - Debug, S, [Event|Events], State, Data, P); - Stacktrace -> - terminate( - error, undef, Stacktrace, - Debug, S, [Event|Events], State, Data, P) - end; + {ok,Result,S}; Class:Reason -> - Stacktrace = erlang:get_stacktrace(), - terminate( - Class, Reason, Stacktrace, - Debug, S, [Event|Events], State, Data, P) + {Class,Reason,erlang:get_stacktrace()} end. + %% Interpret all callback return variants -loop_event_result( - Parent, Debug, S, Events, State, Data, P, Event, Result) -> +parse_event_result( + AllowStateChange, Debug, S, + Events, Event, State, Data, Result) -> case Result of stop -> terminate( - exit, normal, ?STACKTRACE(), - Debug, S, [Event|Events], State, Data, P); + exit, normal, ?STACKTRACE(), Debug, + S#{state := State, data := Data}, + [Event|Events]); {stop,Reason} -> terminate( - exit, Reason, ?STACKTRACE(), - Debug, S, [Event|Events], State, Data, P); + exit, Reason, ?STACKTRACE(), Debug, + S#{state := State, data := Data}, + [Event|Events]); {stop,Reason,NewData} -> terminate( - exit, Reason, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P); + 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, State, Data, P, 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, Q, State, NewData, P, Replies); - {next_state,NextState,NewData} -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, []); - {next_state,NextState,NewData,Actions} -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions); + exit, Reason, ?STACKTRACE(), Debug, + S#{state := State, data := NewData}, + [Event|Events], Replies); + %% + {next_state,State,NewData} -> + {State,NewData,[],false}; + {next_state,NextState,NewData} when AllowStateChange -> + {NextState,NewData,[],true}; + {next_state,State,NewData,Actions} -> + {State,NewData,Actions,false}; + {next_state,NextState,NewData,Actions} when AllowStateChange -> + {NextState,NewData,Actions,true}; + %% {keep_state,NewData} -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, State, []); + {State,NewData,[],false}; {keep_state,NewData,Actions} -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, State, Actions); + {State,NewData,Actions,false}; keep_state_and_data -> - loop_event_actions( - Parent, Debug, S, Events, - State, Data, P, Event, State, []); + {State,Data,[],false}; {keep_state_and_data,Actions} -> - loop_event_actions( - Parent, Debug, S, Events, - State, Data, P, Event, 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_value,Result}, ?STACKTRACE(), - Debug, S, [Event|Events], State, Data, P) + error, + {bad_return_from_state_function,Result}, + ?STACKTRACE(), Debug, + S#{state := State, data := Data}, + [Event|Events]) end. -loop_event_actions( - Parent, Debug, S, Events, State, NewData, P, Event, NextState, Actions) -> - Postpone = false, % Shall we postpone this event; boolean() + +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, - Timeout = undefined, - NextEvents = [], - loop_event_actions( - Parent, Debug, S, Events, State, NewData, P, Event, NextState, - if - is_list(Actions) -> - Actions; - true -> - [Actions] - end, - Postpone, Hibernate, Timeout, NextEvents). + TimeoutsR = [{timeout,infinity,infinity}], %% Will cancel event timer + Postpone = false, + NextEventsR = [], + parse_actions( + Debug, S, State, listify(Actions), + Hibernate, TimeoutsR, Postpone, NextEventsR). %% -%% Process all actions -loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, [Action|Actions], - Postpone, Hibernate, Timeout, NextEvents) -> +parse_actions( + Debug, _S, _State, [], + Hibernate, TimeoutsR, Postpone, NextEventsR) -> + {ok,Debug,Hibernate,TimeoutsR,Postpone,NextEventsR}; +parse_actions( + Debug, S, State, [Action|Actions], + Hibernate, TimeoutsR, Postpone, NextEventsR) -> case Action of %% Actual actions {reply,From,Reply} -> case from(From) of true -> NewDebug = do_reply(Debug, S, State, From, Reply), - loop_event_actions( - Parent, NewDebug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, Hibernate, Timeout, NextEvents); - false -> - terminate( - error, {bad_action,Action}, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P) - end; - {next_event,Type,Content} -> - case event_type(Type) of - true -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, Hibernate, Timeout, - [{Type,Content}|NextEvents]); + parse_actions( + NewDebug, S, State, Actions, + Hibernate, TimeoutsR, Postpone, NextEventsR); false -> - terminate( - error, {bad_action,Action}, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P) + {error, + {bad_action_from_state_function,Action}, + ?STACKTRACE()} end; + %% %% Actions that set options - {postpone,NewPostpone} when is_boolean(NewPostpone) -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - NewPostpone, Hibernate, Timeout, NextEvents); - {postpone,_} -> - terminate( - error, {bad_action,Action}, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P); - postpone -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - true, Hibernate, Timeout, NextEvents); {hibernate,NewHibernate} when is_boolean(NewHibernate) -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, NewHibernate, Timeout, NextEvents); - {hibernate,_} -> - terminate( - error, {bad_action,Action}, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P); + parse_actions( + Debug, S, State, Actions, + NewHibernate, TimeoutsR, Postpone, NextEventsR); hibernate -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, true, Timeout, NextEvents); - {timeout,infinity,_} -> % Clear timer - it will never trigger - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, Hibernate, undefined, NextEvents); - {timeout,Time,_} = NewTimeout when is_integer(Time), Time >= 0 -> - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, Hibernate, NewTimeout, NextEvents); - {timeout,_,_} -> - terminate( - error, {bad_action,Action}, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P); - infinity -> % Clear timer - it will never trigger - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, Hibernate, undefined, NextEvents); - Time when is_integer(Time), Time >= 0 -> - NewTimeout = {timeout,Time,Time}, - loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P, Event, NextState, Actions, - Postpone, Hibernate, NewTimeout, NextEvents); - _ -> - terminate( - error, {bad_action,Action}, ?STACKTRACE(), - Debug, S, [Event|Events], State, NewData, P) - end; -%% -%% End of actions list -loop_event_actions( - Parent, Debug, S, Events, - State, NewData, P0, Event, NextState, [], - Postpone, Hibernate, Timeout, NextEvents) -> - %% - %% All options have been collected and next_events are buffered. - %% Do the actual state transition. - %% - P1 = % Move current event to postponed if Postpone - case Postpone of - true -> - [Event|P0]; - false -> - P0 - end, - {Q2,P} = % Move all postponed events to queue if state change - if - NextState =:= State -> - {Events,P1}; - true -> - {lists:reverse(P1, Events),[]} + NewHibernate = true, + parse_actions( + Debug, S, State, Actions, + NewHibernate, TimeoutsR, Postpone, NextEventsR); + %% + {postpone,NewPostpone} + when is_boolean(NewPostpone), Postpone =/= forbidden -> + parse_actions( + Debug, S, State, Actions, + Hibernate, TimeoutsR, NewPostpone, NextEventsR); + postpone when Postpone =/= forbidden -> + NewPostpone = true, + parse_actions( + Debug, S, State, Actions, + Hibernate, TimeoutsR, NewPostpone, NextEventsR); + %% + {next_event,Type,Content} -> + case event_type(Type) of + true when NextEventsR =/= forbidden -> + NewDebug = + sys_debug(Debug, S, State, {in,{Type,Content}}), + parse_actions( + NewDebug, S, State, Actions, + Hibernate, TimeoutsR, Postpone, + [{Type,Content}|NextEventsR]); + _ -> + {error, + {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, - %% Place next events first in queue - Q = lists:reverse(NextEvents, Q2), - %% - NewDebug = - sys_debug( - Debug, S, State, - case Postpone of - true -> - {postpone,Event,NextState}; - false -> - {consume,Event,NextState} - end), - loop_events( - Parent, NewDebug, S, Q, NextState, NewData, P, Hibernate, Timeout). + case validate_time(Time) of + true -> + parse_actions( + Debug, S, State, Actions, + Hibernate, [Timeout|TimeoutsR], + Postpone, NextEventsR); + false -> + {error, + {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, CancelTimers, TimeoutsR) -> + parse_timers(TimerRefs, TimerTypes, CancelTimers, TimeoutsR, #{}, []). +%% +parse_timers( + 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, CancelTimers, TimeoutsR, + Seen, TimeoutEvents); + #{} -> + %% Unseen type - handle + NewSeen = Seen#{TimerType => true}, + case Time of + infinity -> + %% Cancel any running timer + {NewTimerTypes,NewCancelTimers} = + cancel_timer_by_type( + TimerType, TimerTypes, CancelTimers), + parse_timers( + TimerRefs, NewTimerTypes, NewCancelTimers, TimeoutsR, + NewSeen, TimeoutEvents); + 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]); + _ -> + %% (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 (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]). + + %%--------------------------------------------------------------------------- %% Server helpers reply_then_terminate( - Class, Reason, Stacktrace, - Debug, S, Q, State, Data, P, Replies) -> - if - is_list(Replies) -> - do_reply_then_terminate( - Class, Reason, Stacktrace, - Debug, S, Q, State, Data, P, Replies); - true -> - do_reply_then_terminate( - Class, Reason, Stacktrace, - Debug, S, Q, State, Data, P, [Replies]) - 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, Data, P, []) -> - terminate(Class, Reason, Stacktrace, Debug, S, Q, State, Data, P); + Class, Reason, Stacktrace, Debug, S, Q, [], _State) -> + terminate(Class, Reason, Stacktrace, Debug, S, Q); do_reply_then_terminate( - Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, [R|Rs]) -> + Class, Reason, Stacktrace, Debug, S, Q, [R|Rs], State) -> case R of {reply,{_To,_Tag}=From,Reply} -> NewDebug = do_reply(Debug, S, State, From, Reply), do_reply_then_terminate( - Class, Reason, Stacktrace, - NewDebug, S, Q, State, Data, P, Rs); + Class, Reason, Stacktrace, NewDebug, S, Q, Rs, State); _ -> terminate( - error, {bad_action,R}, ?STACKTRACE(), - Debug, S, Q, State, Data, P) + error, + {bad_reply_action_from_state_function,R}, + ?STACKTRACE(), + Debug, S, Q) end. do_reply(Debug, S, State, From, Reply) -> @@ -1179,28 +1559,40 @@ do_reply(Debug, S, State, From, Reply) -> terminate( - Class, Reason, Stacktrace, - Debug, #{module := Module} = S, Q, State, Data, P) -> - try Module:terminate(Reason, State, Data) of - _ -> ok - catch - _ -> ok; - C:R -> - ST = erlang:get_stacktrace(), - error_info( - C, R, ST, Debug, S, Q, P, - format_status(terminate, get(), S, State, Data)), - erlang:raise(C, R, ST) - end, - case Reason of - normal -> ok; - shutdown -> ok; - {shutdown,_} -> ok; - _ -> - error_info( - Class, Reason, Stacktrace, Debug, S, Q, P, - format_status(terminate, get(), S, State, Data)) + Class, Reason, Stacktrace, Debug, + #{module := Module, state := State, data := Data, postponed := P} = S, + Q) -> + 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 + normal -> + sys_debug(Debug, S, State, {terminate,Reason}); + shutdown -> + sys_debug(Debug, S, State, {terminate,Reason}); + {shutdown,_} -> + sys_debug(Debug, S, State, {terminate,Reason}); + _ -> + error_info( + Class, Reason, Stacktrace, S, Q, P, + format_status(terminate, get(), S)), + sys:print_log(Debug) + end, case Stacktrace of [] -> erlang:Class(Reason); @@ -1209,8 +1601,10 @@ terminate( end. error_info( - Class, Reason, Stacktrace, Debug, - #{name := Name, callback_mode := CallbackMode}, + Class, Reason, Stacktrace, + #{name := Name, + callback_mode := CallbackMode, + state_enter := StateEnter}, Q, P, FmtData) -> {FixedReason,FixedStacktrace} = case Stacktrace of @@ -1237,6 +1631,13 @@ error_info( end; _ -> {Reason,Stacktrace} end, + CBMode = + case StateEnter of + true -> + [CallbackMode,state_enter]; + false -> + CallbackMode + end, error_logger:format( "** State machine ~p terminating~n" ++ case Q of @@ -1263,8 +1664,9 @@ error_info( [] -> []; [Event|_] -> [Event] end] ++ - [FmtData,Class,FixedReason, - CallbackMode] ++ + [FmtData, + Class,FixedReason, + CBMode] ++ case Q of [_|[_|_] = Events] -> [Events]; _ -> [] @@ -1276,13 +1678,13 @@ error_info( case FixedStacktrace of [] -> []; _ -> [FixedStacktrace] - end), - sys:print_log(Debug), - ok. + end). %% Call Module:format_status/2 or return a default value -format_status(Opt, PDict, #{module := Module}, State, Data) -> +format_status( + Opt, PDict, + #{module := Module, state := State, data := Data}) -> case erlang:function_exported(Module, format_status, 2) of true -> try Module:format_status(Opt, [PDict,State,Data]) @@ -1291,7 +1693,7 @@ format_status(Opt, PDict, #{module := Module}, State, Data) -> _:_ -> format_status_default( Opt, State, - "Module:format_status/2 crashed") + atom_to_list(Module) ++ ":format_status/2 crashed") end; false -> format_status_default(Opt, State, Data) @@ -1299,10 +1701,35 @@ format_status(Opt, PDict, #{module := Module}, State, Data) -> %% The default Module:format_status/2 format_status_default(Opt, State, Data) -> - SSD = {State,Data}, + StateData = {State,Data}, case Opt of terminate -> - SSD; + StateData; _ -> - [{data,[{"State",SSD}]}] + [{data,[{"State",StateData}]}] + end. + +listify(Item) when is_list(Item) -> + Item; +listify(Item) -> + [Item]. + +%% Cancel timer if running, otherwise no op +%% +%% 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(TimerType, TimerTypes),CancelTimers + 1}; + #{} -> + {TimerTypes,CancelTimers} end. + +cancel_timer(TimerRef) -> + ok = erlang:cancel_timer(TimerRef, [{async,true}]). |