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-rw-r--r--lib/stdlib/src/gen_statem.erl260
1 files changed, 153 insertions, 107 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl
index c02e6a1a19..3b3477b282 100644
--- a/lib/stdlib/src/gen_statem.erl
+++ b/lib/stdlib/src/gen_statem.erl
@@ -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
@@ -63,8 +63,8 @@
{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 functios
+ term(). % For handle_event/4 callback function
-type state_name() :: atom().
@@ -174,28 +174,33 @@
%% 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()} |
+ {ok, state(), data()} |
+ {ok, state(), data(), [action()] | action()} |
'ignore' |
{'stop', Reason :: term()}.
-%% Example state callback for callback_mode() =:= state_functions
-%% state name 'state_name'.
+%% This callback shall return the callback mode of the callback module.
%%
-%% In this mode all states has to be type state_name() i.e atom().
+%% 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().
+
+%% Example state callback for StateName = 'state_name'
+%% when callback_mode() =:= state_functions.
+%%
+%% 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(),
EventContent :: term(),
Data :: data()) ->
state_function_result().
%%
-%% 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(),
EventContent :: term(),
@@ -219,9 +224,7 @@
OldState :: state(),
OldData :: data(),
Extra :: term()) ->
- {CallbackMode :: callback_mode(),
- NewState :: state(),
- NewData :: data()} |
+ {ok, NewState :: state(), NewData :: data()} |
(Reason :: term()).
%% Format the callback module state in some sensible that is
@@ -240,10 +243,13 @@
[init/1, % One may use enter_loop/5,6,7 instead
format_status/2, % Has got a default implementation
%%
- 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) ->
@@ -451,43 +457,35 @@ 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
@@ -515,7 +513,7 @@ 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),
@@ -531,7 +529,7 @@ enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) ->
[Actions,{postpone,false}]
end,
S = #{
- callback_mode => CallbackMode,
+ callback_mode => undefined,
module => Module,
name => Name,
%% All fields below will be replaced according to the arguments to
@@ -559,9 +557,15 @@ 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},
+ [], [], undefined),
+ erlang:raise(Class, Reason, Stacktrace)
end.
%%---------------------------------------------------------------------------
@@ -569,30 +573,12 @@ 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}),
@@ -602,8 +588,14 @@ 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},
+ [], [], undefined),
exit(Error)
end.
@@ -631,11 +623,9 @@ system_code_change(
Result -> Result
end
of
- {CallbackMode,NewState,NewData} ->
- callback_mode(CallbackMode) orelse
- error({callback_mode,CallbackMode}),
+ {ok,NewState,NewData} ->
{ok,
- S#{callback_mode := CallbackMode,
+ S#{callback_mode := undefined,
state := NewState,
data := NewData}};
{ok,_} = Error ->
@@ -676,14 +666,14 @@ 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 received ~s~n",
- [Name,event_string(Event)]);
-print_event(Dev, {out,Reply,{To,_Tag}}, {Name,_}) ->
+ 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 sent ~p to ~p~n",
- [Name,Reply,To]);
+ Dev, "*DBG* ~p send ~p to ~p from state ~p~n",
+ [Name,Reply,To,State]);
print_event(Dev, {Tag,Event,NextState}, {Name,State}) ->
StateString =
case NextState of
@@ -875,22 +865,36 @@ loop_event(
%%
try
case CallbackMode of
+ undefined ->
+ Module:callback_mode();
state_functions ->
- Module:State(Type, Content, Data);
+ erlang:apply(Module, State, [Type,Content,Data]);
handle_event_function ->
Module:handle_event(Type, Content, State, Data)
- end of
+ end
+ of
+ Result when CallbackMode =:= undefined ->
+ loop_event_callback_mode(
+ Parent, Debug, S, Events, State, Data, P, Event, Result);
Result ->
loop_event_result(
Parent, Debug, S, Events, State, Data, P, Event, Result)
catch
+ Result when CallbackMode =:= undefined ->
+ loop_event_callback_mode(
+ Parent, Debug, S, Events, State, Data, P, Event, Result);
Result ->
loop_event_result(
Parent, Debug, S, Events, State, Data, P, Event, Result);
- error:badarg when CallbackMode =:= state_functions ->
+ error:badarg ->
case erlang:get_stacktrace() of
- [{erlang,apply,[Module,State,_],_}|Stacktrace] ->
- Args = [Type,Content,Data],
+ [{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
terminate(
error,
{undef_state_function,{Module,State,Args}},
@@ -902,24 +906,29 @@ loop_event(
Debug, S, [Event|Events], State, Data, P)
end;
error:undef ->
- %% Process an undef to check for the simple mistake
+ %% 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,
- _}
+ [{Module,callback_mode,[]=Args,_}
+ |Stacktrace]
+ when CallbackMode =:= undefined ->
+ terminate(
+ error,
+ {undef_callback,{Module,callback_mode,Args}},
+ Stacktrace,
+ Debug, S, [Event|Events], State, Data, P);
+ [{Module,State,[Type,Content,Data]=Args,_}
|Stacktrace]
- when CallbackMode =:= state_functions ->
+ 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,
- _}
+ [{Module,handle_event,[Type,Content,State,Data]=Args,_}
|Stacktrace]
- when CallbackMode =:= handle_event_function ->
+ when CallbackMode =:= handle_event_function ->
terminate(
error,
{undef_state_function,{Module,handle_event,Args}},
@@ -937,6 +946,25 @@ loop_event(
Debug, S, [Event|Events], State, Data, P)
end.
+%% Interpret callback_mode() result
+loop_event_callback_mode(
+ Parent, Debug, S, Events, State, Data, P, Event, CallbackMode) ->
+ case callback_mode(CallbackMode) of
+ true ->
+ Hibernate = false, % We have already GC:ed recently
+ loop_event(
+ Parent, Debug,
+ S#{callback_mode := CallbackMode},
+ Events,
+ State, Data, P, Event, Hibernate);
+ false ->
+ terminate(
+ error,
+ {bad_return_from_callback_mode,CallbackMode},
+ ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P)
+ end.
+
%% Interpret all callback return variants
loop_event_result(
Parent, Debug, S, Events, State, Data, P, Event, Result) ->
@@ -989,7 +1017,9 @@ loop_event_result(
State, Data, P, Event, State, Actions);
_ ->
terminate(
- error, {bad_return_value,Result}, ?STACKTRACE(),
+ error,
+ {bad_return_from_state_function,Result},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, Data, P)
end.
@@ -1026,20 +1056,26 @@ loop_event_actions(
Postpone, Hibernate, Timeout, NextEvents);
false ->
terminate(
- error, {bad_action,Action}, ?STACKTRACE(),
+ error,
+ {bad_action_from_state_function,Action},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, NewData, P)
end;
{next_event,Type,Content} ->
case event_type(Type) of
true ->
+ NewDebug =
+ sys_debug(Debug, S, State, {in,{Type,Content}}),
loop_event_actions(
- Parent, Debug, S, Events,
+ Parent, NewDebug, S, Events,
State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, Timeout,
[{Type,Content}|NextEvents]);
false ->
terminate(
- error, {bad_action,Action}, ?STACKTRACE(),
+ error,
+ {bad_action_from_state_function,Action},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, NewData, P)
end;
%% Actions that set options
@@ -1050,7 +1086,9 @@ loop_event_actions(
NewPostpone, Hibernate, Timeout, NextEvents);
{postpone,_} ->
terminate(
- error, {bad_action,Action}, ?STACKTRACE(),
+ error,
+ {bad_action_from_state_function,Action},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, NewData, P);
postpone ->
loop_event_actions(
@@ -1064,7 +1102,9 @@ loop_event_actions(
Postpone, NewHibernate, Timeout, NextEvents);
{hibernate,_} ->
terminate(
- error, {bad_action,Action}, ?STACKTRACE(),
+ error,
+ {bad_action_from_state_function,Action},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, NewData, P);
hibernate ->
loop_event_actions(
@@ -1083,7 +1123,9 @@ loop_event_actions(
Postpone, Hibernate, NewTimeout, NextEvents);
{timeout,_,_} ->
terminate(
- error, {bad_action,Action}, ?STACKTRACE(),
+ error,
+ {bad_action_from_state_function,Action},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, NewData, P);
infinity -> % Clear timer - it will never trigger
loop_event_actions(
@@ -1098,7 +1140,9 @@ loop_event_actions(
Postpone, Hibernate, NewTimeout, NextEvents);
_ ->
terminate(
- error, {bad_action,Action}, ?STACKTRACE(),
+ error,
+ {bad_action_from_state_function,Action},
+ ?STACKTRACE(),
Debug, S, [Event|Events], State, NewData, P)
end;
%%
@@ -1170,7 +1214,9 @@ do_reply_then_terminate(
NewDebug, S, Q, State, Data, P, Rs);
_ ->
terminate(
- error, {bad_action,R}, ?STACKTRACE(),
+ error,
+ {bad_reply_action_from_state_function,R},
+ ?STACKTRACE(),
Debug, S, Q, State, Data, P)
end.
@@ -1189,8 +1235,9 @@ terminate(
C:R ->
ST = erlang:get_stacktrace(),
error_info(
- C, R, ST, Debug, S, Q, P,
+ C, R, ST, S, Q, P,
format_status(terminate, get(), S, State, Data)),
+ sys:print_log(Debug),
erlang:raise(C, R, ST)
end,
case Reason of
@@ -1199,8 +1246,9 @@ terminate(
{shutdown,_} -> ok;
_ ->
error_info(
- Class, Reason, Stacktrace, Debug, S, Q, P,
- format_status(terminate, get(), S, State, Data))
+ Class, Reason, Stacktrace, S, Q, P,
+ format_status(terminate, get(), S, State, Data)),
+ sys:print_log(Debug)
end,
case Stacktrace of
[] ->
@@ -1210,7 +1258,7 @@ terminate(
end.
error_info(
- Class, Reason, Stacktrace, Debug,
+ Class, Reason, Stacktrace,
#{name := Name, callback_mode := CallbackMode},
Q, P, FmtData) ->
{FixedReason,FixedStacktrace} =
@@ -1277,9 +1325,7 @@ error_info(
case FixedStacktrace of
[] -> [];
_ -> [FixedStacktrace]
- end),
- sys:print_log(Debug),
- ok.
+ end).
%% Call Module:format_status/2 or return a default value
@@ -1292,7 +1338,7 @@ 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)
@@ -1300,10 +1346,10 @@ 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.
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-09 04:43:28 +0000