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authorRaimo Niskanen <[email protected]>2016-04-21 15:58:52 +0200
committerRaimo Niskanen <[email protected]>2016-04-21 15:58:52 +0200
commit26b3c7d60d52d8a7be006b06d856bb0f7276e77a (patch)
tree82fe6796d1139babe79073d7c4e392d7d7a5dc90 /lib/stdlib/src
parent2977fbc6b658b0d664f7d3b36ecf8ca9e897aaa3 (diff)
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Modify code_change/4 to return CallbackMode
Also move check of non-atom states in callback mode state_functions to where the state function is called. This gives homogenous diagnostics for state functions, code_change/4 and system_replace_state StateFun. Irregularities pointed out by James Fish.
Diffstat (limited to 'lib/stdlib/src')
-rw-r--r--lib/stdlib/src/gen_statem.erl60
1 files changed, 31 insertions, 29 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl
index b3a149a569..c85c521d8e 100644
--- a/lib/stdlib/src/gen_statem.erl
+++ b/lib/stdlib/src/gen_statem.erl
@@ -219,7 +219,9 @@
OldState :: state(),
OldData :: data(),
Extra :: term()) ->
- {ok, NewState :: state(), NewData :: data()}.
+ {NewCallbackMode :: callback_mode(),
+ NewState :: state(),
+ NewData :: data()}.
%% Format the callback module state in some sensible that is
%% often condensed way. For StatusOption =:= 'normal' the perferred
@@ -491,17 +493,10 @@ enter_loop(Module, Opts, CallbackMode, State, Data, Server_or_Actions) ->
Actions :: [action()] | action()) ->
no_return().
enter_loop(Module, Opts, CallbackMode, State, Data, Server, Actions) ->
- case is_atom(Module) andalso callback_mode(CallbackMode) of
- true ->
- Parent = gen:get_parent(),
- enter(
- Module, Opts, CallbackMode, State, Data, Server,
- Actions, Parent);
- false ->
- error(
- badarg,
- [Module,Opts,CallbackMode,State,Data,Server,Actions])
- end.
+ 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).
%%---------------------------------------------------------------------------
%% API helpers
@@ -580,15 +575,13 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) ->
case Result of
{CallbackMode,State,Data} ->
case callback_mode(CallbackMode) of
- true
- when CallbackMode =:= state_functions, is_atom(State);
- CallbackMode =/= state_functions ->
+ true ->
proc_lib:init_ack(Starter, {ok,self()}),
enter(
Module, Opts, CallbackMode, State, Data,
ServerRef, [], Parent);
false ->
- Error = {bad_return_value,Result},
+ Error = {callback_mode,CallbackMode},
proc_lib:init_ack(Starter, {error,Error}),
exit(Error)
end;
@@ -600,7 +593,7 @@ init_result(Starter, Parent, ServerRef, Module, Result, Opts) ->
Module, Opts, CallbackMode, State, Data,
ServerRef, Actions, Parent);
false ->
- Error = {bad_return_value,Result},
+ Error = {callback_mode,CallbackMode},
proc_lib:init_ack(Starter, {error,Error}),
exit(Error)
end;
@@ -638,11 +631,12 @@ system_code_change(
Result -> Result
end
of
- {ok,NewState,NewData} ->
- {ok,
- S#{
- state := NewState,
- data := NewData}};
+ {NewCallbackMode,NewState,NewData} ->
+ callback_mode(NewCallbackMode) orelse
+ error({callback_mode,NewCallbackMode}),
+ {ok,S#{state := NewState, data := NewData}};
+ {ok,_} = Error ->
+ error({case_clause,Error});
Error ->
Error
end.
@@ -825,6 +819,18 @@ loop_events(
Result ->
loop_event_result(
Parent, Debug, S, Events, 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, Q);
+ Stacktrace ->
+ terminate(error, badarg, Stacktrace, Debug, S, Q)
+ end;
error:undef ->
%% Process an undef to check for the simple mistake
%% of calling a nonexistent state function
@@ -861,7 +867,7 @@ loop_events(
%% Interpret all callback return variants
loop_event_result(
Parent, Debug,
- #{callback_mode := CallbackMode, state := State, data := Data} = S,
+ #{state := State, data := Data} = S,
Events, Event, Result) ->
case Result of
stop ->
@@ -887,15 +893,11 @@ loop_event_result(
exit, Reason, ?STACKTRACE(), Debug, NewS, Q, Replies),
%% Since we got back here Replies was bad
terminate(Class, NewReason, Stacktrace, NewDebug, NewS, Q);
- {next_state,NextState,NewData}
- when CallbackMode =:= state_functions, is_atom(NextState);
- CallbackMode =/= state_functions ->
+ {next_state,NextState,NewData} ->
loop_event_actions(
Parent, Debug, S, Events, Event,
State, NextState, NewData, []);
- {next_state,NextState,NewData,Actions}
- when CallbackMode =:= state_functions, is_atom(NextState);
- CallbackMode =/= state_functions ->
+ {next_state,NextState,NewData,Actions} ->
loop_event_actions(
Parent, Debug, S, Events, Event,
State, NextState, NewData, Actions);