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authorRaimo Niskanen <[email protected]>2016-02-16 10:51:39 +0100
committerRaimo Niskanen <[email protected]>2016-02-16 11:02:22 +0100
commit3815de0c7337058991066454c246587c0dbaa664 (patch)
tree57ee28e46cb622c6b0110c524ea00443b65db433 /lib/stdlib/src/gen_statem.erl
parenta07f6e35c3adb6e1536a63cc8137f48f64e2f6f7 (diff)
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Change to {next_state,...} and {stop,...} return format
Diffstat (limited to 'lib/stdlib/src/gen_statem.erl')
-rw-r--r--lib/stdlib/src/gen_statem.erl103
1 files changed, 67 insertions, 36 deletions
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl
index 9bb5ed013b..7c3cd8c2f3 100644
--- a/lib/stdlib/src/gen_statem.erl
+++ b/lib/stdlib/src/gen_statem.erl
@@ -74,14 +74,13 @@
{'retry', Retry :: boolean()} |
'hibernate' | % Hibernate the server instead of going into receive
{'hibernate', Hibernate :: boolean()} |
+ (Timeout :: timeout()) | % {timeout,Timeout}
{'timeout', % Generate a ('timeout', Msg, ...) event after Time
Time :: timeout(), Msg :: term()}.
-type state_operation() ::
%% These can occur multiple times and are executed in order
%% of appearence in the state_op() list
- {'reply', % Reply to a client
- Client :: client(), Reply :: term()} |
- {'stop', Reason :: term()} | % Stop the server
+ reply_operation() |
{'insert_event', % Insert event as the next to handle
EventType :: event_type(),
EventContent :: term()} |
@@ -95,6 +94,9 @@
MonitorRef :: reference()} |
{'unlink', % Unlink and clean up mess(ages)
Id :: pid() | port()}.
+-type reply_operation() ::
+ {'reply', % Reply to a client
+ Client :: client(), Reply :: term()}.
%% The state machine init function. It is called only once and
%% the server is not running until this function has returned
@@ -122,12 +124,20 @@
PrevState :: state(),
State :: state(), % Current state
StateData :: state_data()) ->
- [state_op()] | % {State,StateData,[state_op()]}
- {} | % {State,StateData,[]}
- {NewStateData :: state_data()} | % {State,NewStateData,[retry]}
- {NewState :: state(),
- NewStateData :: state_data()} | % {NewState,NewStateData,[]}
- {NewState :: state(), NewStateData :: state_data(), [state_op()]}.
+ {stop, % Stop the server
+ Reason :: term(),
+ NewStateData :: state_data()} |
+ {stop, % Stop the server
+ Reason :: term(),
+ [reply_operation()] | reply_operation(),
+ NewStateData :: state_data()} |
+ {next_state, % {next_state,NewState,NewStateData,[]}
+ NewState :: state(),
+ NewStateData :: state_data()} |
+ {next_state, % State transition, maybe to the same state
+ NewState :: state(),
+ NewStateData :: state_data(),
+ [state_op()] | state_op()}.
%% Clean up before the server terminates.
-callback terminate(
@@ -679,35 +689,42 @@ loop_events(
terminate(Class, Reason, Stacktrace, Debug, S, Q)
end.
-%% Interprete all callback return value variants
-loop_event_result(
- Parent, Debug,
- #{state := State, state_data := StateData} = S,
- Events, Event, Result) ->
+%% Interpret all callback return value variants
+loop_event_result(Parent, Debug, S, Events, Event, Result) ->
case Result of
- {} -> % Ignore
- loop_event_state_ops(
- Parent, Debug, S, Events, Event,
- State, StateData, []);
- {NewStateData} -> % Retry
- loop_event_state_ops(
- Parent, Debug, S, Events, Event,
- State, NewStateData, [retry]);
- {NewState,NewStateData} -> % Consume
+ {stop,Reason,NewStateData} ->
+ terminate(
+ Reason, Debug,
+ S#{state_data := NewStateData},
+ [Event|Events]);
+ {stop,Reason,Reply,NewStateData} ->
+ NewS = S#{state_data := NewStateData},
+ Q = [Event|Events],
+ Replies =
+ if
+ is_list(Reply) ->
+ Reply;
+ true ->
+ [Reply]
+ end,
+ BadReplies =
+ reply_then_terminate(Reason, Debug, NewS, Q, Replies),
+ %% Since it returned Replies was bad
+ terminate(
+ {bad_return_value,{stop,Reason,BadReplies,NewStateData}},
+ Debug, NewS, Q);
+ {next_state,NewState,NewStateData} ->
loop_event_state_ops(
Parent, Debug, S, Events, Event,
NewState, NewStateData, []);
- {NewState,NewStateData,StateOps} when is_list(StateOps) ->
+ {next_state,NewState,NewStateData,StateOps}
+ when is_list(StateOps) ->
loop_event_state_ops(
Parent, Debug, S, Events, Event,
NewState, NewStateData, StateOps);
- StateOps when is_list(StateOps) -> % Stay in state
- loop_event_state_ops(
- Parent, Debug, S, Events, Event,
- State, StateData, StateOps);
- BadReturn ->
+ _ ->
terminate(
- {bad_return_value,BadReturn}, Debug, S, [Event|Events])
+ {bad_return_value,Result}, Debug, S, [Event|Events])
end.
loop_event_state_ops(
@@ -750,7 +767,8 @@ loop_event_state_ops(
%% Pretend the timeout has just been received
{undefined,Q3 ++ [{timeout,Msg}]};
{timeout,Time,Msg} ->
- {erlang:start_timer(Time, self(), Msg),Q3}
+ {erlang:start_timer(Time, self(), Msg),
+ Q3}
end,
loop_events(
Parent, NewDebug,
@@ -820,11 +838,8 @@ process_state_operations([], Debug, _S, Q, P) ->
process_state_operations([Operation|Operations] = OOs, Debug, S, Q, P) ->
case Operation of
{reply,{_To,_Tag}=Client,Reply} ->
- reply(Client, Reply),
- NewDebug = sys_debug(Debug, S, {out,Reply,Client}),
+ NewDebug = do_reply(Debug, S, Client, Reply),
process_state_operations(Operations, NewDebug, S, Q, P);
- {stop,Reason} ->
- [Reason,Debug];
{insert_event,Type,Content} ->
case event_type(Type) of
true ->
@@ -854,6 +869,22 @@ process_state_operations([Operation|Operations] = OOs, Debug, S, Q, P) ->
end
end.
+reply_then_terminate(Reason, Debug, S, Q, []) ->
+ terminate(Reason, Debug, S, Q);
+reply_then_terminate(Reason, Debug, S, Q, [R|Rs] = RRs) ->
+ case R of
+ {reply,{_To,_Tag}=Client,Reply} ->
+ NewDebug = do_reply(Debug, S, Client, Reply),
+ reply_then_terminate(Reason, NewDebug, S, Q, Rs);
+ _ ->
+ RRs % bad_return_value
+ end.
+
+do_reply(Debug, S, Client, Reply) ->
+ reply(Client, Reply),
+ sys_debug(Debug, S, {out,Reply,Client}).
+
+
%% Remove oldest matching event from the queue(s)
remove_event(RemoveFun, Q, P) ->
try
@@ -928,7 +959,7 @@ remove_fun({unlink,Id}) ->
end
catch
Class:Reason ->
- {Class,Reason,erlang:get_stacktrace()}
+ [Class,Reason,erlang:get_stacktrace()]
end;
remove_fun(_) ->
undefined.