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Fix format_status bug for unregistered gen_event processes

Port the gen_fsm code for format_status to gen_event in order to
prevent a lists:concat([...,pid()]) crash when calling
sys:get_status/1 on an unregistered gen_event process.

Refactor format_status header code from gen_* behaviours to module gen.

Extend the format_status tests in gen_event_SUITE to cover
format_status bugs with anonymous gen_event processes.
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1 parent c752a4e commit 95ed86fc9893460751c5141ff872bdc13814a273 @archaelus archaelus committed with RaimoNiskanen Jun 12, 2010
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@@ -29,6 +29,8 @@
-export([init_it/6, init_it/7]).
+-export([format_status_header/2]).
+
-define(default_timeout, 5000).
%%-----------------------------------------------------------------
@@ -315,3 +317,10 @@ debug_options(Opts) ->
{ok, Options} -> sys:debug_options(Options);
_ -> []
end.
+
+format_status_header(TagLine, Pid) when is_pid(Pid) ->
+ lists:concat([TagLine, " ", pid_to_list(Pid)]);
+format_status_header(TagLine, RegName) when is_atom(RegName) ->
+ lists:concat([TagLine, " ", RegName]);
+format_status_header(TagLine, Name) ->
+ {TagLine, Name}.
@@ -724,7 +724,8 @@ get_modules(MSL) ->
%%-----------------------------------------------------------------
format_status(Opt, StatusData) ->
[PDict, SysState, Parent, _Debug, [ServerName, MSL, _Hib]] = StatusData,
- Header = lists:concat(["Status for event handler ", ServerName]),
+ Header = gen:format_status_header("Status for event handler",
+ ServerName),
FmtMSL = [case erlang:function_exported(Mod, format_status, 2) of
true ->
Args = [PDict, State],
View
@@ -614,15 +614,8 @@ get_msg(Msg) -> Msg.
format_status(Opt, StatusData) ->
[PDict, SysState, Parent, Debug, [Name, StateName, StateData, Mod, _Time]] =
StatusData,
- StatusHdr = "Status for state machine",
- Header = if
- is_pid(Name) ->
- lists:concat([StatusHdr, " ", pid_to_list(Name)]);
- is_atom(Name); is_list(Name) ->
- lists:concat([StatusHdr, " ", Name]);
- true ->
- {StatusHdr, Name}
- end,
+ Header = gen:format_status_header("Status for state machine",
+ Name),
Log = sys:get_debug(log, Debug, []),
DefaultStatus = [{data, [{"StateData", StateData}]}],
Specfic =
@@ -840,15 +840,8 @@ name_to_pid(Name) ->
%%-----------------------------------------------------------------
format_status(Opt, StatusData) ->
[PDict, SysState, Parent, Debug, [Name, State, Mod, _Time]] = StatusData,
- StatusHdr = "Status for generic server",
- Header = if
- is_pid(Name) ->
- lists:concat([StatusHdr, " ", pid_to_list(Name)]);
- is_atom(Name); is_list(Name) ->
- lists:concat([StatusHdr, " ", Name]);
- true ->
- {StatusHdr, Name}
- end,
+ Header = gen:format_status_header("Status for generic server",
+ Name),
Log = sys:get_debug(log, Debug, []),
DefaultStatus = [{data, [{"State", State}]}],
Specfic =
@@ -24,10 +24,12 @@
-export([start/1, test_all/1, add_handler/1, add_sup_handler/1,
delete_handler/1, swap_handler/1, swap_sup_handler/1,
notify/1, sync_notify/1, call/1, info/1, hibernate/1,
- call_format_status/1, error_format_status/1]).
+ call_format_status/1, call_format_status_anon/1,
+ error_format_status/1]).
all(suite) -> {req, [stdlib], [start, test_all, hibernate,
- call_format_status, error_format_status]}.
+ call_format_status, call_format_status_anon,
+ error_format_status]}.
%% --------------------------------------
%% Start an event manager.
@@ -868,6 +870,22 @@ call_format_status(Config) when is_list(Config) ->
?line {"Installed handlers", [{_,dummy1_h,_,FmtState,_}]} = HandlerInfo2,
ok.
+call_format_status_anon(suite) ->
+ [];
+call_format_status_anon(doc) ->
+ ["Test that sys:get_status/1,2 calls format_status/2 for anonymous gen_event processes"];
+call_format_status_anon(Config) when is_list(Config) ->
+ ?line {ok, Pid} = gen_event:start(),
+ %% The 'Name' of the gen_event process will be a pid() here, so
+ %% the next line will crash if format_status can't string-ify pids.
+ ?line Status1 = sys:get_status(Pid),
+ ?line ok = gen_event:stop(Pid),
+ Header = "Status for event handler " ++ pid_to_list(Pid),
+ ?line {status, Pid, _, [_, _, Pid, [], Data1]} = Status1,
+ ?line Header = proplists:get_value(header, Data1),
+ ok.
+
+
error_format_status(suite) ->
[];
error_format_status(doc) ->

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