Merge branch 'sv/format_status_error_info' into dev

* sv/format_status_error_info:
  Add support for the format_status callback to gen_event
  Extend format_status for gen_server/gen_fsm termination error logging

OTP-8630 sv/format_status_error_info

When a gen_server, gen_fsm process, or gen_event terminates abnormally,
sometimes the text representation of the process state can occupy many
lines of the error log, depending on the definition of the state term. A
mechanism to trim out parts of the state from the log has been added (using
a format_status/2 callback). See the documentation.

4 files changed, 135 insertions, 22 deletions

diff --git a/lib/stdlib/test/dummy1_h.erl b/lib/stdlib/test/dummy1_h.erl
index 4377d774a3..5b503d5984 100644
--- a/lib/stdlib/test/dummy1_h.erl
+++ b/lib/stdlib/test/dummy1_h.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 -module(dummy1_h).
@@ -21,7 +21,7 @@
 %% Test event handler for gen_event_SUITE.erl
 
 -export([init/1, handle_event/2, handle_call/2, handle_info/2,
-	 terminate/2]).
+	 terminate/2, format_status/2]).
 
 init(make_error) ->
     {error, my_error};
@@ -67,4 +67,5 @@ terminate(remove_handler, Parent) ->
 terminate(_Reason, _State) ->
     ok.
 
-
+format_status(_Opt, [_PDict, _State]) ->
+    "dummy1_h handler state".
diff --git a/lib/stdlib/test/gen_event_SUITE.erl b/lib/stdlib/test/gen_event_SUITE.erl
index 8cbffaca56..4f7de451e3 100644
--- a/lib/stdlib/test/gen_event_SUITE.erl
+++ b/lib/stdlib/test/gen_event_SUITE.erl
@@ -23,9 +23,11 @@
 -export([all/1]).
 -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]).
+	 notify/1, sync_notify/1, call/1, info/1, hibernate/1,
+	 call_format_status/1, error_format_status/1]).
 
-all(suite) -> {req, [stdlib], [start, test_all, hibernate]}.
+all(suite) -> {req, [stdlib], [start, test_all, hibernate,
+			       call_format_status, error_format_status]}.
 
 %% --------------------------------------
 %% Start an event manager.
@@ -844,3 +846,56 @@ info(Config) when is_list(Config) ->
 
     ?line ok = gen_event:stop(my_dummy_handler),
     ok.
+
+call_format_status(suite) ->
+    [];
+call_format_status(doc) ->
+    ["Test that sys:get_status/1,2 calls format_status/2"];
+call_format_status(Config) when is_list(Config) ->
+    ?line {ok, Pid} = gen_event:start({local, my_dummy_handler}),
+    %% State here intentionally differs from what we expect from format_status
+    State = self(),
+    FmtState = "dummy1_h handler state",
+    ?line ok = gen_event:add_handler(my_dummy_handler, dummy1_h, [State]),
+    ?line Status1 = sys:get_status(Pid),
+    ?line Status2 = sys:get_status(Pid, 5000),
+    ?line ok = gen_event:stop(Pid),
+    ?line {status, Pid, _, [_, _, Pid, [], Data1]} = Status1,
+    ?line HandlerInfo1 = proplists:get_value(items, Data1),
+    ?line {"Installed handlers", [{_,dummy1_h,_,FmtState,_}]} = HandlerInfo1,
+    ?line {status, Pid, _, [_, _, Pid, [], Data2]} = Status2,
+    ?line HandlerInfo2 = proplists:get_value(items, Data2),
+    ?line {"Installed handlers", [{_,dummy1_h,_,FmtState,_}]} = HandlerInfo2,
+    ok.
+
+error_format_status(suite) ->
+    [];
+error_format_status(doc) ->
+    ["Test that a handler error calls format_status/2"];
+error_format_status(Config) when is_list(Config) ->
+    ?line error_logger_forwarder:register(),
+    OldFl = process_flag(trap_exit, true),
+    State = self(),
+    ?line {ok, Pid} = gen_event:start({local, my_dummy_handler}),
+    ?line ok = gen_event:add_sup_handler(my_dummy_handler, dummy1_h, [State]),
+    ?line ok = gen_event:notify(my_dummy_handler, do_crash),
+    ?line receive
+	      {gen_event_EXIT,dummy1_h,{'EXIT',_}} -> ok
+	  after 5000 ->
+		  ?t:fail(exit_gen_event)
+	  end,
+    FmtState = "dummy1_h handler state",
+    receive
+	{error,_GroupLeader, {Pid,
+			      "** gen_event handler"++_,
+			      [dummy1_h,my_dummy_handler,do_crash,
+			       FmtState, _]}} ->
+	    ok;
+	Other ->
+	    ?line io:format("Unexpected: ~p", [Other]),
+	    ?line ?t:fail()
+    end,
+    ?t:messages_get(),
+    ?line ok = gen_event:stop(Pid),
+    process_flag(trap_exit, OldFl),
+    ok.
diff --git a/lib/stdlib/test/gen_fsm_SUITE.erl b/lib/stdlib/test/gen_fsm_SUITE.erl
index 23c1d9a193..d61eeb403b 100644
--- a/lib/stdlib/test/gen_fsm_SUITE.erl
+++ b/lib/stdlib/test/gen_fsm_SUITE.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 -module(gen_fsm_SUITE).
@@ -30,7 +30,7 @@
 
 -export([shutdown/1]).
 
--export([sys/1, sys1/1, call_format_status/1]).
+-export([sys/1, sys1/1, call_format_status/1, error_format_status/1]).
 
 -export([hibernate/1,hiber_idle/3,hiber_wakeup/3,hiber_idle/2,hiber_wakeup/2]).
 
@@ -305,7 +305,7 @@ shutdown(Config) when is_list(Config) ->
     ok.
 
 
-sys(suite) -> [sys1, call_format_status].
+sys(suite) -> [sys1, call_format_status, error_format_status].
 
 sys1(Config) when is_list(Config) ->
     ?line {ok, Pid} = 
@@ -324,6 +324,27 @@ call_format_status(Config) when is_list(Config) ->
     ?line [format_status_called | _] = lists:reverse(Data),
     ?line stop_it(Pid).
 
+error_format_status(Config) when is_list(Config) ->
+    ?line error_logger_forwarder:register(),
+    OldFl = process_flag(trap_exit, true),
+    StateData = "called format_status",
+    ?line {ok, Pid} = gen_fsm:start(gen_fsm_SUITE, {state_data, StateData}, []),
+    %% bad return value in the gen_fsm loop
+    ?line {'EXIT',{{bad_return_value, badreturn},_}} =
+	(catch gen_fsm:sync_send_event(Pid, badreturn)),
+    receive
+	{error,_GroupLeader,{Pid,
+			     "** State machine"++_,
+			     [Pid,{_,_,badreturn},idle,StateData,_]}} ->
+	    ok;
+	Other ->
+	    ?line io:format("Unexpected: ~p", [Other]),
+	    ?line ?t:fail()
+    end,
+    ?t:messages_get(),
+    process_flag(trap_exit, OldFl),
+    ok.
+
 
 %% Hibernation
 hibernate(suite) -> [];
@@ -704,6 +725,8 @@ init(hiber) ->
     {ok, hiber_idle, []};
 init(hiber_now) ->
     {ok, hiber_idle, [], hibernate};
+init({state_data, StateData}) ->
+    {ok, idle, StateData};
 init(_) ->
     {ok, idle, state_data}.
 
@@ -844,5 +867,7 @@ handle_sync_event(stop_shutdown_reason, _From, _State, Data) ->
 handle_sync_event({get, _Pid}, _From, State, Data) ->
     {reply, {state, State, Data}, State, Data}.
 
-format_status(_Opt, [_Pdict, _StateData]) ->
+format_status(terminate, [_Pdict, StateData]) ->
+    StateData;
+format_status(normal, [_Pdict, _StateData]) ->
     [format_status_called].
diff --git a/lib/stdlib/test/gen_server_SUITE.erl b/lib/stdlib/test/gen_server_SUITE.erl
index 0f60c2c4ee..0966734c89 100644
--- a/lib/stdlib/test/gen_server_SUITE.erl
+++ b/lib/stdlib/test/gen_server_SUITE.erl
@@ -31,7 +31,7 @@
 	 spec_init_local_registered_parent/1, 
 	 spec_init_global_registered_parent/1,
 	 otp_5854/1, hibernate/1, otp_7669/1, call_format_status/1,
-	 call_with_huge_message_queue/1
+	 error_format_status/1, call_with_huge_message_queue/1
 	]).
 
 % spawn export
@@ -52,7 +52,8 @@ all(suite) ->
      call_remote_n2, call_remote_n3, spec_init,
      spec_init_local_registered_parent,
      spec_init_global_registered_parent,
-     otp_5854, hibernate, otp_7669, call_format_status,
+     otp_5854, hibernate, otp_7669,
+     call_format_status, error_format_status,
      call_with_huge_message_queue].
 
 -define(default_timeout, ?t:minutes(1)).
@@ -897,7 +898,7 @@ call_format_status(doc) ->
     ["Test that sys:get_status/1,2 calls format_status/2"];
 call_format_status(Config) when is_list(Config) ->
     ?line {ok, Pid} = gen_server:start_link({local, call_format_status},
-                                            gen_server_SUITE, [], []),
+					    ?MODULE, [], []),
     ?line Status1 = sys:get_status(call_format_status),
     ?line {status, Pid, _Mod, [_PDict, running, _Parent, _, Data1]} = Status1,
     ?line [format_status_called | _] = lists:reverse(Data1),
@@ -906,6 +907,35 @@ call_format_status(Config) when is_list(Config) ->
     ?line [format_status_called | _] = lists:reverse(Data2),
     ok.
 
+%% Verify that error termination correctly calls our format_status/2 fun
+%%
+error_format_status(suite) ->
+    [];
+error_format_status(doc) ->
+    ["Test that an error termination calls format_status/2"];
+error_format_status(Config) when is_list(Config) ->
+    ?line error_logger_forwarder:register(),
+    OldFl = process_flag(trap_exit, true),
+    State = "called format_status",
+    ?line {ok, Pid} = gen_server:start_link(?MODULE, {state, State}, []),
+    ?line {'EXIT',{crashed,_}} = (catch gen_server:call(Pid, crash)),
+    receive
+	{'EXIT', Pid, crashed} ->
+	    ok
+    end,
+    receive
+	{error,_GroupLeader,{Pid,
+			     "** Generic server"++_,
+			     [Pid,crash,State,crashed]}} ->
+	    ok;
+	Other ->
+	    ?line io:format("Unexpected: ~p", [Other]),
+	    ?line ?t:fail()
+    end,
+    ?t:messages_get(),
+    process_flag(trap_exit, OldFl),
+    ok.
+
 %% Test that the time for a huge message queue is not
 %% significantly slower than with an empty message queue.
 call_with_huge_message_queue(Config) when is_list(Config) ->
@@ -1105,5 +1135,7 @@ terminate({From, stopped_info}, _State) ->
 terminate(_Reason, _State) ->
     ok.
 
-format_status(_Opt, [_PDict, _State]) ->
-    [format_status_called].
+format_status(terminate, [_PDict, State]) ->
+    State;
+format_status(normal, [_PDict, _State]) ->
+    format_status_called.