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authorRaimo Niskanen <[email protected]>2016-05-04 14:37:35 +0200
committerRaimo Niskanen <[email protected]>2016-05-04 14:37:35 +0200
commit2a9fbb1c76334f0211214a0aee517ec03de0e487 (patch)
tree70ae785a80975a7d1750bae6da971279a1d895df
parent6a1290f534164d1a5771dba37c23124652b9f7c9 (diff)
parent1f145f8a444121fac1f15dfe4af54f2148419ac1 (diff)
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Merge branch 'raimo/polish-gen_statem/OTP-13065'
* raimo/polish-gen_statem/OTP-13065: Fix documentation Clean up terminate functions Fix callback mode after code change not used Restructure loop_* to clarify S handling
-rw-r--r--lib/stdlib/doc/src/gen_statem.xml6
-rw-r--r--lib/stdlib/src/gen_statem.erl493
-rw-r--r--lib/stdlib/test/gen_statem_SUITE.erl10
-rw-r--r--system/doc/design_principles/code_lock.diabin2955 -> 2932 bytes
-rw-r--r--system/doc/design_principles/code_lock.pngbin58823 -> 59160 bytes
-rw-r--r--system/doc/design_principles/code_lock_2.diabin2646 -> 2621 bytes
-rw-r--r--system/doc/design_principles/code_lock_2.pngbin51848 -> 48927 bytes
-rw-r--r--system/doc/design_principles/fsm.xml2
8 files changed, 279 insertions, 232 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml
index ec7f267c64..d83e17b177 100644
--- a/lib/stdlib/doc/src/gen_statem.xml
+++ b/lib/stdlib/doc/src/gen_statem.xml
@@ -396,17 +396,17 @@ handle_event(_, _, State, Data) ->
<tag><c>pid()</c><br />
<c>LocalName</c></tag>
<item>The <c>gen_statem</c> is locally registered.</item>
- <tag><c>Name, Node</c></tag>
+ <tag><c>{Name,Node}</c></tag>
<item>
The <c>gen_statem</c> is locally registered
on another node.
</item>
- <tag><c>GlobalName</c></tag>
+ <tag><c>{global,GlobalName}</c></tag>
<item>
The <c>gen_statem</c> is globally registered
in <seealso marker="kernel:global"><c>global</c></seealso>.
</item>
- <tag><c>RegMod, ViaName</c></tag>
+ <tag><c>{via,RegMod,ViaName}</c></tag>
<item>
The <c>gen_statem</c> is registered through
an alternative process registry.
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl
index f9e2e5f7d2..23bddafeed 100644
--- a/lib/stdlib/src/gen_statem.erl
+++ b/lib/stdlib/src/gen_statem.erl
@@ -97,7 +97,7 @@
%% * Postponing the current event is performed
%% iff 'postpone' is 'true'.
%% * A state timer is started iff 'timeout' is set.
- %% * Pending events are processed or if there are
+ %% * Pending events are handled or if there are
%% no pending events the server goes into receive
%% or hibernate (iff 'hibernate' is 'true')
%%
@@ -282,16 +282,6 @@ event_type(Type) ->
STACKTRACE(),
try throw(ok) catch _ -> erlang:get_stacktrace() end).
--define(
- TERMINATE(Class, Reason, Debug, S, Q),
- terminate(
- begin Class end,
- begin Reason end,
- ?STACKTRACE(),
- begin Debug end,
- begin S end,
- begin Q end)).
-
%%%==========================================================================
%%% API
@@ -300,11 +290,11 @@ event_type(Type) ->
| {'via', RegMod :: module(), Name :: term()}
| {'local', atom()}.
-type server_ref() ::
- {'global', GlobalName :: term()}
- | {'via', RegMod :: module(), ViaName :: term()}
+ pid()
| (LocalName :: atom())
| {Name :: atom(), Node :: atom()}
- | pid().
+ | {'global', GlobalName :: term()}
+ | {'via', RegMod :: module(), ViaName :: term()}.
-type debug_opt() ::
{'debug',
Dbgs ::
@@ -523,12 +513,15 @@ send(Proc, Msg) ->
ok
end.
-%% Here init_it/6 and enter_loop/5,6,7 functions converge
+%% Here the init_it/6 and enter_loop/5,6,7 functions converge
enter(Module, Opts, CallbackMode, 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),
- PrevState = make_ref(), % Will be discarded by loop_event_actions/9
+ P = Events = [],
+ Event = {internal,initial_state},
+ %% We enforce {postpone,false} to ensure that
+ %% our fake Event gets discarded, thought it might get logged
NewActions =
if
is_list(Actions) ->
@@ -540,15 +533,17 @@ enter(Module, Opts, CallbackMode, State, Data, Server, Actions, Parent) ->
callback_mode => CallbackMode,
module => Module,
name => Name,
- state => PrevState,
+ %% 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,
- timer => undefined,
- postponed => [],
- hibernate => false},
+ postponed => P,
+ hibernate => false,
+ timer => undefined},
+ NewDebug = sys_debug(Debug, S, State, {enter,Event,State}),
loop_event_actions(
- Parent, Debug, S, [],
- {event,undefined}, % Will be discarded thanks to {postpone,false}
- PrevState, State, Data, NewActions).
+ Parent, NewDebug, S, Events,
+ State, Data, P, Event, State, NewActions).
%%%==========================================================================
%%% gen callbacks
@@ -617,8 +612,12 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) ->
system_continue(Parent, Debug, S) ->
loop(Parent, Debug, S).
-system_terminate(Reason, _Parent, Debug, S) ->
- ?TERMINATE(exit, Reason, Debug, S, []).
+system_terminate(
+ Reason, _Parent, Debug,
+ #{state := State, data := Data, postponed := P} = S) ->
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [], State, Data, P).
system_code_change(
#{module := Module,
@@ -634,7 +633,10 @@ system_code_change(
{NewCallbackMode,NewState,NewData} ->
callback_mode(NewCallbackMode) orelse
error({callback_mode,NewCallbackMode}),
- {ok,S#{state := NewState, data := NewData}};
+ {ok,
+ S#{callback_mode := NewCallbackMode,
+ state := NewState,
+ data := NewData}};
{ok,_} = Error ->
error({case_clause,Error});
Error ->
@@ -654,7 +656,7 @@ system_replace_state(
format_status(
Opt,
[PDict,SysState,Parent,Debug,
- #{name := Name, postponed := P} = S]) ->
+ #{name := Name, postponed := P, state := State, data := Data} = S]) ->
Header = gen:format_status_header("Status for state machine", Name),
Log = sys:get_debug(log, Debug, []),
[{header,Header},
@@ -663,7 +665,7 @@ format_status(
{"Parent",Parent},
{"Logged Events",Log},
{"Postponed",P}]} |
- case format_status(Opt, PDict, S) of
+ case format_status(Opt, PDict, S, State, Data) of
L when is_list(L) -> L;
T -> [T]
end].
@@ -673,21 +675,21 @@ format_status(
%% them, not as the real erlang messages. Use trace for that.
%%---------------------------------------------------------------------------
-print_event(Dev, {in,Event}, #{name := Name}) ->
+print_event(Dev, {in,Event}, {Name,_}) ->
io:format(
Dev, "*DBG* ~p received ~s~n",
[Name,event_string(Event)]);
-print_event(Dev, {out,Reply,{To,_Tag}}, #{name := Name}) ->
+print_event(Dev, {out,Reply,{To,_Tag}}, {Name,_}) ->
io:format(
Dev, "*DBG* ~p sent ~p to ~p~n",
[Name,Reply,To]);
-print_event(Dev, {Tag,Event,NewState}, #{name := Name, state := State}) ->
+print_event(Dev, {Tag,Event,NextState}, {Name,State}) ->
StateString =
- case NewState of
+ case NextState of
State ->
io_lib:format("~p", [State]);
_ ->
- io_lib:format("~p => ~p", [State,NewState])
+ io_lib:format("~p => ~p", [State,NextState])
end,
io:format(
Dev, "*DBG* ~p ~w ~s in state ~s~n",
@@ -697,16 +699,17 @@ event_string(Event) ->
case Event of
{{call,{Pid,_Tag}},Request} ->
io_lib:format("call ~p from ~w", [Request,Pid]);
- {Tag,Content} ->
- io_lib:format("~w ~p", [Tag,Content])
+ {EventType,EventContent} ->
+ io_lib:format("~w ~p", [EventType,EventContent])
end.
-sys_debug(Debug, S, Entry) ->
+sys_debug(Debug, #{name := Name}, State, Entry) ->
case Debug of
[] ->
Debug;
_ ->
- sys:handle_debug(Debug, fun print_event/3, S, Entry)
+ sys:handle_debug(
+ Debug, fun print_event/3, {Name,State}, Entry)
end.
%%%==========================================================================
@@ -720,7 +723,7 @@ wakeup_from_hibernate(Parent, Debug, S) ->
%%% State Machine engine implementation of proc_lib/gen server
%% Server loop, consists of all loop* functions
-%% and some detours through sys and proc_lib
+%% 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) ->
@@ -749,12 +752,16 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) ->
sys:handle_system_msg(
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, Debug, S, [EXIT]);
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [EXIT], State, Data, P);
{timeout,Timer,Content} when Timer =/= undefined ->
- loop_event(Parent, Debug, S, {timeout,Content});
+ loop_receive_result(
+ Parent, Debug, S, {timeout,Content});
_ ->
%% Cancel Timer if running
case Timer of
@@ -782,30 +789,81 @@ loop_receive(Parent, Debug, #{timer := Timer} = S) ->
_ ->
{info,Msg}
end,
- loop_event(Parent, Debug, S, Event)
+ loop_receive_result(Parent, Debug, S, Event)
end
end.
-loop_event(Parent, Debug, S, Event) ->
- %% The timer field and the hibernate flag in S
- %% are now invalid and ignored until we get back to loop/3
- NewDebug = sys_debug(Debug, S, {in,Event}),
- %% Here the queue of not yet processed events is created
- loop_events(Parent, NewDebug, S, [Event], false).
-
-%% Process first the event queue, or if it is empty
-%% loop back to receive a new event
-loop_events(Parent, Debug, S, [], _Hibernate) ->
- loop(Parent, Debug, S);
+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.
+ %%
+ NewDebug = sys_debug(Debug, S, State, {in,Event}),
+ %% Here the queue of not yet handled events is 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)
+ 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).
+
+loop_event(
Parent, Debug,
#{callback_mode := CallbackMode,
- module := Module,
- state := State,
- data := Data} = S,
- [{Type,Content} = Event|Events] = Q,
- Hibernate) ->
- %% If the Hibernate flag is true here it can only be
+ module := Module} = S,
+ Events,
+ State, Data, P, {Type,Content} = Event, Hibernate) ->
+ %%
+ %% If 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
@@ -813,6 +871,7 @@ loop_events(
%% would have happened if we actually hibernated
%% and immediately was awakened
Hibernate andalso garbage_collect(),
+ %%
try
case CallbackMode of
state_functions ->
@@ -822,11 +881,11 @@ loop_events(
end of
Result ->
loop_event_result(
- Parent, Debug, S, Events, Event, Result)
+ Parent, Debug, S, Events, State, Data, P, Event, Result)
catch
Result ->
loop_event_result(
- Parent, Debug, S, Events, 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] ->
@@ -835,9 +894,11 @@ loop_events(
error,
{undef_state_function,{Module,State,Args}},
Stacktrace,
- Debug, S, Q);
+ Debug, S, [Event|Events], State, Data, P);
Stacktrace ->
- terminate(error, badarg, Stacktrace, Debug, S, Q)
+ terminate(
+ error, badarg, Stacktrace,
+ Debug, S, [Event|Events], State, Data, P)
end;
error:undef ->
%% Process an undef to check for the simple mistake
@@ -852,7 +913,7 @@ loop_events(
error,
{undef_state_function,{Module,State,Args}},
Stacktrace,
- Debug, S, Q);
+ Debug, S, [Event|Events], State, Data, P);
[{Module,handle_event,
[Type,Content,State,Data]=Args,
_}
@@ -860,86 +921,85 @@ loop_events(
when CallbackMode =:= handle_event_function ->
terminate(
error,
- {undef_state_function,
- {Module,handle_event,Args}},
+ {undef_state_function,{Module,handle_event,Args}},
Stacktrace,
- Debug, S, Q);
+ Debug, S, [Event|Events], State, Data, P);
Stacktrace ->
- terminate(error, undef, Stacktrace, Debug, S, Q)
+ terminate(
+ error, undef, Stacktrace,
+ Debug, S, [Event|Events], State, Data, P)
end;
Class:Reason ->
Stacktrace = erlang:get_stacktrace(),
- terminate(Class, Reason, Stacktrace, Debug, S, Q)
+ terminate(
+ Class, Reason, Stacktrace,
+ Debug, S, [Event|Events], State, Data, P)
end.
%% Interpret all callback return variants
loop_event_result(
- Parent, Debug,
- #{state := State, data := Data} = S,
- Events, Event, Result) ->
- %% From now until we loop back to the loop_events/4
- %% the state and data fields in S are old
+ Parent, Debug, S, Events, State, Data, P, Event, Result) ->
case Result of
stop ->
- ?TERMINATE(exit, normal, Debug, S, [Event|Events]);
+ terminate(
+ exit, normal, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P);
{stop,Reason} ->
- ?TERMINATE(exit, Reason, Debug, S, [Event|Events]);
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P);
{stop,Reason,NewData} ->
- NewS = S#{data := NewData},
- Q = [Event|Events],
- ?TERMINATE(exit, Reason, Debug, NewS, Q);
+ terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
{stop_and_reply,Reason,Replies} ->
Q = [Event|Events],
- [Class,NewReason,Stacktrace,NewDebug] =
- reply_then_terminate(
- exit, Reason, ?STACKTRACE(), Debug, S, Q, Replies),
- %% Since we got back here Replies was bad
- terminate(Class, NewReason, Stacktrace, NewDebug, S, Q);
+ reply_then_terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, Q, State, Data, P, Replies);
{stop_and_reply,Reason,Replies,NewData} ->
- NewS = S#{data := NewData},
Q = [Event|Events],
- [Class,NewReason,Stacktrace,NewDebug] =
- reply_then_terminate(
- exit, Reason, ?STACKTRACE(), Debug, NewS, Q, Replies),
- %% Since we got back here Replies was bad
- terminate(Class, NewReason, Stacktrace, NewDebug, NewS, Q);
+ reply_then_terminate(
+ exit, Reason, ?STACKTRACE(),
+ Debug, S, Q, State, NewData, P, Replies);
{next_state,NextState,NewData} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, []);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, []);
{next_state,NextState,NewData,Actions} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions);
{keep_state,NewData} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, NewData, []);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, State, []);
{keep_state,NewData,Actions} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, NewData, Actions);
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, State, Actions);
keep_state_and_data ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, Data, []);
+ Parent, Debug, S, Events,
+ State, Data, P, Event, State, []);
{keep_state_and_data,Actions} ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, State, Data, Actions);
+ Parent, Debug, S, Events,
+ State, Data, P, Event, State, Actions);
_ ->
- ?TERMINATE(
- error, {bad_return_value,Result}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_return_value,Result}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, Data, P)
end.
loop_event_actions(
- Parent, Debug, S, Events, Event, State, NextState, NewData, Actions) ->
- Postpone = false, % Shall we postpone this event, true or false
+ Parent, Debug, S, Events, State, NewData, P, Event, NextState, Actions) ->
+ Postpone = false, % Shall we postpone this event; boolean()
Hibernate = false,
Timeout = undefined,
NextEvents = [],
loop_event_actions(
- Parent, Debug, S, Events, Event, State, NextState, NewData,
+ Parent, Debug, S, Events, State, NewData, P, Event, NextState,
if
is_list(Actions) ->
Actions;
@@ -948,97 +1008,103 @@ loop_event_actions(
end,
Postpone, Hibernate, Timeout, NextEvents).
%%
-%% Process all action()s
+%% Process all actions
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, [Action|Actions],
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, [Action|Actions],
Postpone, Hibernate, Timeout, NextEvents) ->
case Action of
%% Actual actions
{reply,From,Reply} ->
case from(From) of
true ->
- NewDebug = do_reply(Debug, S, From, Reply),
+ NewDebug = do_reply(Debug, S, State, From, Reply),
loop_event_actions(
- Parent, NewDebug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, NewDebug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, Timeout, NextEvents);
false ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events])
+ 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, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, Timeout,
[{Type,Content}|NextEvents]);
false ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P)
end;
%% Actions that set options
{postpone,NewPostpone} when is_boolean(NewPostpone) ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
NewPostpone, Hibernate, Timeout, NextEvents);
{postpone,_} ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events]);
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
postpone ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, 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, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, NewHibernate, Timeout, NextEvents);
{hibernate,_} ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events]);
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P);
hibernate ->
loop_event_actions(
- Parent, Debug, S, Events, Event,
- State, NextState, NewData, 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, Event,
- State, NextState, NewData, 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, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, NewTimeout, NextEvents);
{timeout,_,_} ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events]);
+ 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, Event,
- State, NextState, NewData, 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, Event,
- State, NextState, NewData, Actions,
+ Parent, Debug, S, Events,
+ State, NewData, P, Event, NextState, Actions,
Postpone, Hibernate, NewTimeout, NextEvents);
_ ->
- ?TERMINATE(
- error, {bad_action,Action}, Debug, S, [Event|Events])
+ terminate(
+ error, {bad_action,Action}, ?STACKTRACE(),
+ Debug, S, [Event|Events], State, NewData, P)
end;
%%
%% End of actions list
loop_event_actions(
- Parent, Debug, #{postponed := P0} = S, Events, Event,
- State, NextState, NewData, [],
+ Parent, Debug, S, Events,
+ State, NewData, P0, Event, NextState, [],
Postpone, Hibernate, Timeout, NextEvents) ->
%%
%% All options have been collected and next_events are buffered.
@@ -1059,89 +1125,62 @@ loop_event_actions(
{lists:reverse(P1, Events),[]}
end,
%% Place next events first in queue
- Q3 = lists:reverse(NextEvents, Q2),
+ Q = lists:reverse(NextEvents, Q2),
%%
NewDebug =
sys_debug(
- Debug, S,
+ Debug, S, State,
case Postpone of
true ->
{postpone,Event,NextState};
false ->
{consume,Event,NextState}
end),
- %% Have a peek on the event queue so we can avoid starting
- %% the state timer unless we have to
- {Q,Timer} =
- case Timeout of
- undefined ->
- %% No state timeout has been requested
- {Q3,undefined};
- {timeout,Time,EventContent} ->
- %% A state timeout has been requested
- case Q3 of
- [] when Time =:= 0 ->
- %% Immediate timeout - simulate it
- %% so we do not get the timeout message
- %% after any received event
- {[{timeout,EventContent}],undefined};
- [] ->
- %% Actually start a timer
- {Q3,erlang:start_timer(Time, self(), EventContent)};
- _ ->
- %% Do not start a timer since any queued
- %% event cancels the state timer so we pretend
- %% that the timer has been started and cancelled
- {Q3,undefined}
- end
- end,
- %% Loop to top of event queue loop; process next event
loop_events(
- Parent, NewDebug,
- S#{
- state := NextState,
- data := NewData,
- timer := Timer,
- postponed := P,
- hibernate := Hibernate},
- Q, Hibernate).
+ Parent, NewDebug, S, Q, NextState, NewData, P, Hibernate, Timeout).
%%---------------------------------------------------------------------------
%% Server helpers
-reply_then_terminate(Class, Reason, Stacktrace, Debug, S, Q, Replies) ->
+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, Replies);
+ Class, Reason, Stacktrace,
+ Debug, S, Q, State, Data, P, Replies);
true ->
do_reply_then_terminate(
- Class, Reason, Stacktrace, Debug, S, Q, [Replies])
+ Class, Reason, Stacktrace,
+ Debug, S, Q, State, Data, P, [Replies])
end.
%%
-do_reply_then_terminate(Class, Reason, Stacktrace, Debug, S, Q, []) ->
- terminate(Class, Reason, Stacktrace, Debug, S, Q);
do_reply_then_terminate(
- Class, Reason, Stacktrace, Debug, S, Q, [R|Rs]) ->
+ Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, []) ->
+ terminate(Class, Reason, Stacktrace, Debug, S, Q, State, Data, P);
+do_reply_then_terminate(
+ Class, Reason, Stacktrace, Debug, S, Q, State, Data, P, [R|Rs]) ->
case R of
{reply,{_To,_Tag}=From,Reply} ->
- NewDebug = do_reply(Debug, S, From, Reply),
+ NewDebug = do_reply(Debug, S, State, From, Reply),
do_reply_then_terminate(
- Class, Reason, Stacktrace, NewDebug, S, Q, Rs);
+ Class, Reason, Stacktrace,
+ NewDebug, S, Q, State, Data, P, Rs);
_ ->
- [error,{bad_action,R},?STACKTRACE(),Debug]
+ terminate(
+ error, {bad_action,R}, ?STACKTRACE(),
+ Debug, S, Q, State, Data, P)
end.
-do_reply(Debug, S, From, Reply) ->
+do_reply(Debug, S, State, From, Reply) ->
reply(From, Reply),
- sys_debug(Debug, S, {out,Reply,From}).
+ sys_debug(Debug, S, State, {out,Reply,From}).
terminate(
- Class, Reason, Stacktrace, Debug,
- #{module := Module,
- state := State, data := Data} = S,
- Q) ->
+ Class, Reason, Stacktrace,
+ Debug, #{module := Module} = S, Q, State, Data, P) ->
try Module:terminate(Reason, State, Data) of
_ -> ok
catch
@@ -1149,8 +1188,8 @@ terminate(
C:R ->
ST = erlang:get_stacktrace(),
error_info(
- C, R, ST, Debug, S, Q,
- format_status(terminate, get(), S)),
+ C, R, ST, Debug, S, Q, P,
+ format_status(terminate, get(), S, State, Data)),
erlang:raise(C, R, ST)
end,
case Reason of
@@ -1159,8 +1198,8 @@ terminate(
{shutdown,_} -> ok;
_ ->
error_info(
- Class, Reason, Stacktrace, Debug, S, Q,
- format_status(terminate, get(), S))
+ Class, Reason, Stacktrace, Debug, S, Q, P,
+ format_status(terminate, get(), S, State, Data))
end,
case Stacktrace of
[] ->
@@ -1171,9 +1210,8 @@ terminate(
error_info(
Class, Reason, Stacktrace, Debug,
- #{name := Name, callback_mode := CallbackMode,
- state := State, postponed := P},
- Q, FmtData) ->
+ #{name := Name, callback_mode := CallbackMode},
+ Q, P, FmtData) ->
{FixedReason,FixedStacktrace} =
case Stacktrace of
[{M,F,Args,_}|ST]
@@ -1202,46 +1240,49 @@ error_info(
error_logger:format(
"** State machine ~p terminating~n" ++
case Q of
- [] ->
- "";
- _ ->
- "** Last event = ~p~n"
+ [] -> "";
+ _ -> "** Last event = ~p~n"
end ++
- "** When Server state = ~p~n" ++
+ "** When server state = ~p~n" ++
"** Reason for termination = ~w:~p~n" ++
- "** State = ~p~n" ++
"** Callback mode = ~p~n" ++
- "** Queued/Postponed = ~w/~w~n" ++
+ case Q of
+ [_,_|_] -> "** Queued = ~p~n";
+ _ -> ""
+ end ++
+ case P of
+ [] -> "";
+ _ -> "** Postponed = ~p~n"
+ end ++
case FixedStacktrace of
- [] ->
- "";
- _ ->
- "** Stacktrace =~n"
- "** ~p~n"
+ [] -> "";
+ _ -> "** Stacktrace =~n** ~p~n"
end,
[Name |
case Q of
- [] ->
- [];
- [Event|_] ->
- [Event]
+ [] -> [];
+ [Event|_] -> [Event]
end] ++
[FmtData,Class,FixedReason,
- State,CallbackMode,length(Q),length(P)] ++
+ CallbackMode] ++
+ case Q of
+ [_|[_|_] = Events] -> [Events];
+ _ -> []
+ end ++
+ case P of
+ [] -> [];
+ _ -> [P]
+ end ++
case FixedStacktrace of
- [] ->
- [];
- _ ->
- [FixedStacktrace]
+ [] -> [];
+ _ -> [FixedStacktrace]
end),
sys:print_log(Debug),
ok.
%% Call Module:format_status/2 or return a default value
-format_status(
- Opt, PDict,
- #{module := Module, state := State, data := Data}) ->
+format_status(Opt, PDict, #{module := Module}, State, Data) ->
case erlang:function_exported(Module, format_status, 2) of
true ->
try Module:format_status(Opt, [PDict,State,Data])
diff --git a/lib/stdlib/test/gen_statem_SUITE.erl b/lib/stdlib/test/gen_statem_SUITE.erl
index 3deb5fd986..364314f91b 100644
--- a/lib/stdlib/test/gen_statem_SUITE.erl
+++ b/lib/stdlib/test/gen_statem_SUITE.erl
@@ -634,12 +634,14 @@ sys1(Config) ->
stop_it(Pid).
code_change(Config) ->
+ Mode = handle_event_function,
{ok,Pid} = gen_statem:start(?MODULE, start_arg(Config, []), []),
{idle,data} = sys:get_state(Pid),
sys:suspend(Pid),
- sys:change_code(Pid, ?MODULE, old_vsn, state_functions),
+ sys:change_code(Pid, ?MODULE, old_vsn, Mode),
sys:resume(Pid),
- {idle,{old_vsn,data,state_functions}} = sys:get_state(Pid),
+ {idle,{old_vsn,data,Mode}} = sys:get_state(Pid),
+ Mode = gen_statem:call(Pid, get_callback_mode),
stop_it(Pid).
call_format_status(Config) ->
@@ -1478,6 +1480,8 @@ next_events(Type, Content, Data) ->
end.
+handle_common_events({call,From}, get_callback_mode, _, _) ->
+ {keep_state_and_data,{reply,From,state_functions}};
handle_common_events({call,From}, get, State, Data) ->
{keep_state,Data,
[{reply,From,{state,State,Data}}]};
@@ -1501,6 +1505,8 @@ handle_common_events(cast, {'alive?',Pid}, _, Data) ->
handle_common_events(_, _, _, _) ->
undefined.
+handle_event({call,From}, get_callback_mode, _, _) ->
+ {keep_state_and_data,{reply,From,handle_event_function}};
%% Wrapper state machine that uses a map state machine spec
handle_event(
Type, Event, State, [Data|Machine])
diff --git a/system/doc/design_principles/code_lock.dia b/system/doc/design_principles/code_lock.dia
index bed6d8ee86..8e6ff8a898 100644
--- a/system/doc/design_principles/code_lock.dia
+++ b/system/doc/design_principles/code_lock.dia
Binary files differ
diff --git a/system/doc/design_principles/code_lock.png b/system/doc/design_principles/code_lock.png
index e40f0320aa..745fd91920 100644
--- a/system/doc/design_principles/code_lock.png
+++ b/system/doc/design_principles/code_lock.png
Binary files differ
diff --git a/system/doc/design_principles/code_lock_2.dia b/system/doc/design_principles/code_lock_2.dia
index 4e82a9e1d6..142909a2f5 100644
--- a/system/doc/design_principles/code_lock_2.dia
+++ b/system/doc/design_principles/code_lock_2.dia
Binary files differ
diff --git a/system/doc/design_principles/code_lock_2.png b/system/doc/design_principles/code_lock_2.png
index 138fbdef6c..ecf7b0d799 100644
--- a/system/doc/design_principles/code_lock_2.png
+++ b/system/doc/design_principles/code_lock_2.png
Binary files differ
diff --git a/system/doc/design_principles/fsm.xml b/system/doc/design_principles/fsm.xml
index 3468f93ae0..4f2b75e6e8 100644
--- a/system/doc/design_principles/fsm.xml
+++ b/system/doc/design_principles/fsm.xml
@@ -33,7 +33,7 @@
<note>
<p>
There is a new behaviour
- <seealso marker="gen_statem"><c>gen_statem</c></seealso>
+ <seealso marker="statem"><c>gen_statem</c></seealso>
that is intended to replace <c>gen_fsm</c> for new code.
It has the same features and add some really useful.
This module will not be removed for the foreseeable future