%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2017. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(error_logger).
-export([start/0,start_link/0,format/2,error_msg/1,error_msg/2,error_report/1,
error_report/2,info_report/1,info_report/2,warning_report/1,
warning_report/2,error_info/1,
info_msg/1,info_msg/2,warning_msg/1,warning_msg/2,
logfile/1,tty/1,swap_handler/1,
add_report_handler/1,add_report_handler/2,
delete_report_handler/1]).
-export([init/1,
handle_event/2, handle_call/2, handle_info/2,
terminate/2]).
-export([get_format_depth/0, limit_term/1]).
-define(buffer_size, 10).
%%-----------------------------------------------------------------
%% Types used in this file
%%-----------------------------------------------------------------
-type msg_tag() :: 'error' | 'error_report'
| 'info' | 'info_msg' | 'info_report'
| 'warning_msg' | 'warning_report'.
-type state() :: {non_neg_integer(), non_neg_integer(), [term()]}.
%%% BIF
-export([warning_map/0]).
-spec warning_map() -> Tag when
Tag :: error | warning | info.
warning_map() ->
erlang:nif_error(undef).
%%% End of BIF
%%-----------------------------------------------------------------
-spec start() -> {'ok', pid()} | {'error', any()}.
start() ->
case gen_event:start({local, error_logger}) of
{ok, Pid} ->
simple_logger(?buffer_size),
{ok, Pid};
Error -> Error
end.
-spec start_link() -> {'ok', pid()} | {'error', any()}.
start_link() ->
case gen_event:start_link({local, error_logger}) of
{ok, Pid} ->
simple_logger(?buffer_size),
{ok, Pid};
Error -> Error
end.
%%-----------------------------------------------------------------
%% These two simple old functions generate events tagged 'error'
%% Used for simple messages; error or information.
%%-----------------------------------------------------------------
-spec error_msg(Format) -> 'ok' when
Format :: string().
error_msg(Format) ->
error_msg(Format,[]).
-spec error_msg(Format, Data) -> 'ok' when
Format :: string(),
Data :: list().
error_msg(Format, Args) ->
notify({error, group_leader(), {self(), Format, Args}}).
-spec format(Format, Data) -> 'ok' when
Format :: string(),
Data :: list().
format(Format, Args) ->
notify({error, group_leader(), {self(), Format, Args}}).
%%-----------------------------------------------------------------
%% This functions should be used for error reports. Events
%% are tagged 'error_report'.
%% The 'std_error' error_report type can always be used.
%%-----------------------------------------------------------------
-type report() ::
[{Tag :: term(), Data :: term()} | term()] | string() | term().
-spec error_report(Report) -> 'ok' when
Report :: report().
error_report(Report) ->
error_report(std_error, Report).
-spec error_report(Type, Report) -> 'ok' when
Type :: term(),
Report :: report().
error_report(Type, Report) ->
notify({error_report, group_leader(), {self(), Type, Report}}).
%%-----------------------------------------------------------------
%% This function should be used for warning reports.
%% These might be mapped to error reports or info reports,
%% depending on emulator flags. Events that ore not mapped
%% are tagged 'info_report'.
%% The 'std_warning' info_report type can always be used and is
%% mapped to std_info or std_error accordingly.
%%-----------------------------------------------------------------
-spec warning_report(Report) -> 'ok' when
Report :: report().
warning_report(Report) ->
warning_report(std_warning, Report).
-spec warning_report(Type, Report) -> 'ok' when
Type :: any(),
Report :: report().
warning_report(Type, Report) ->
{Tag, NType} = case error_logger:warning_map() of
info ->
if
Type =:= std_warning ->
{info_report, std_info};
true ->
{info_report, Type}
end;
warning ->
{warning_report, Type};
error ->
if
Type =:= std_warning ->
{error_report, std_error};
true ->
{error_report, Type}
end
end,
notify({Tag, group_leader(), {self(), NType, Report}}).
%%-----------------------------------------------------------------
%% This function provides similar functions as error_msg for
%% warning messages, like warning report it might get mapped to
%% other types of reports.
%%-----------------------------------------------------------------
-spec warning_msg(Format) -> 'ok' when
Format :: string().
warning_msg(Format) ->
warning_msg(Format,[]).
-spec warning_msg(Format, Data) -> 'ok' when
Format :: string(),
Data :: list().
warning_msg(Format, Args) ->
Tag = case error_logger:warning_map() of
warning ->
warning_msg;
info ->
info_msg;
error ->
error
end,
notify({Tag, group_leader(), {self(), Format, Args}}).
%%-----------------------------------------------------------------
%% This function should be used for information reports. Events
%% are tagged 'info_report'.
%% The 'std_info' info_report type can always be used.
%%-----------------------------------------------------------------
-spec info_report(Report) -> 'ok' when
Report :: report().
info_report(Report) ->
info_report(std_info, Report).
-spec info_report(Type, Report) -> 'ok' when
Type :: any(),
Report :: report().
info_report(Type, Report) ->
notify({info_report, group_leader(), {self(), Type, Report}}).
%%-----------------------------------------------------------------
%% This function provides similar functions as error_msg for
%% information messages.
%%-----------------------------------------------------------------
-spec info_msg(Format) -> 'ok' when
Format :: string().
info_msg(Format) ->
info_msg(Format,[]).
-spec info_msg(Format, Data) -> 'ok' when
Format :: string(),
Data :: list().
info_msg(Format, Args) ->
notify({info_msg, group_leader(), {self(), Format, Args}}).
%%-----------------------------------------------------------------
%% Used by the init process. Events are tagged 'info'.
%%-----------------------------------------------------------------
-spec error_info(Error :: any()) -> 'ok'.
error_info(Error) ->
notify({info, group_leader(), {self(), Error, []}}).
-spec notify({msg_tag(), pid(), {pid(), any(), any()}}) -> 'ok'.
notify(Msg) ->
gen_event:notify(error_logger, Msg).
-type swap_handler_type() :: 'false' | 'silent' | 'tty' | {'logfile', string()}.
-spec swap_handler(Type :: swap_handler_type()) -> any().
swap_handler(tty) ->
R = gen_event:swap_handler(error_logger, {error_logger, swap},
{error_logger_tty_h, []}),
ok = simple_logger(),
R;
swap_handler({logfile, File}) ->
R = gen_event:swap_handler(error_logger, {error_logger, swap},
{error_logger_file_h, File}),
ok = simple_logger(),
R;
swap_handler(silent) ->
_ = gen_event:delete_handler(error_logger, error_logger, delete),
ok = simple_logger();
swap_handler(false) ->
ok. % keep primitive event handler as-is
-spec add_report_handler(Handler) -> any() when
Handler :: module().
add_report_handler(Module) when is_atom(Module) ->
gen_event:add_handler(error_logger, Module, []).
-spec add_report_handler(Handler, Args) -> Result when
Handler :: module(),
Args :: gen_event:handler_args(),
Result :: gen_event:add_handler_ret().
add_report_handler(Module, Args) when is_atom(Module) ->
gen_event:add_handler(error_logger, Module, Args).
-spec delete_report_handler(Handler) -> Result when
Handler :: module(),
Result :: gen_event:del_handler_ret().
delete_report_handler(Module) when is_atom(Module) ->
gen_event:delete_handler(error_logger, Module, []).
%% Start the lowest level error_logger handler with Buffer.
simple_logger(Buffer_size) when is_integer(Buffer_size) ->
gen_event:add_handler(error_logger, error_logger, Buffer_size).
%% Start the lowest level error_logger handler without Buffer.
simple_logger() ->
gen_event:add_handler(error_logger, error_logger, []).
%% Log all errors to File for all eternity
-type open_error() :: file:posix() | badarg | system_limit.
-spec logfile(Request :: {open, Filename}) -> ok | {error, OpenReason} when
Filename ::file:name(),
OpenReason :: allready_have_logfile | open_error()
; (Request :: close) -> ok | {error, CloseReason} when
CloseReason :: module_not_found
; (Request :: filename) -> Filename | {error, FilenameReason} when
Filename :: file:name(),
FilenameReason :: no_log_file.
logfile({open, File}) ->
case lists:member(error_logger_file_h,
gen_event:which_handlers(error_logger)) of
true ->
{error, allready_have_logfile};
_ ->
gen_event:add_handler(error_logger, error_logger_file_h, File)
end;
logfile(close) ->
case gen_event:delete_handler(error_logger, error_logger_file_h, normal) of
{error,Reason} ->
{error,Reason};
_ ->
ok
end;
logfile(filename) ->
case gen_event:call(error_logger, error_logger_file_h, filename) of
{error,_} ->
{error, no_log_file};
Val ->
Val
end.
%% Possibly turn off all tty printouts, maybe we only want the errors
%% to go to a file
-spec tty(Flag) -> 'ok' when
Flag :: boolean().
tty(true) ->
Hs = gen_event:which_handlers(error_logger),
case lists:member(error_logger_tty_h, Hs) of
false ->
gen_event:add_handler(error_logger, error_logger_tty_h, []);
true ->
ignore
end,
ok;
tty(false) ->
gen_event:delete_handler(error_logger, error_logger_tty_h, []),
ok.
%%% ---------------------------------------------------
%%% This is the default error_logger handler.
%%% ---------------------------------------------------
-spec init(term()) -> {'ok', state() | []}.
init(Max) when is_integer(Max) ->
{ok, {Max, 0, []}};
%% This one is called if someone took over from us, and now wants to
%% go back.
init({go_back, _PostState}) ->
{ok, {?buffer_size, 0, []}};
init(_) ->
%% The error logger process may receive a huge amount of
%% messages. Make sure that they are stored off heap to
%% avoid exessive GCs.
process_flag(message_queue_data, off_heap),
{ok, []}.
-spec handle_event(term(), state()) -> {'ok', state()}.
handle_event({Type, GL, Msg}, State) when node(GL) =/= node() ->
gen_event:notify({error_logger, node(GL)},{Type, GL, Msg}),
%% handle_event2({Type, GL, Msg}, State); %% Shall we do something
{ok, State}; %% at this node too ???
handle_event({info_report, _, {_, Type, _}}, State) when Type =/= std_info ->
{ok, State}; %% Ignore other info reports here
handle_event(Event, State) ->
handle_event2(Event, State).
-spec handle_info(term(), state()) -> {'ok', state()}.
handle_info({emulator, GL, Chars}, State) when node(GL) =/= node() ->
{error_logger, node(GL)} ! {emulator, GL, add_node(Chars,self())},
{ok, State};
handle_info({emulator, GL, Chars}, State) ->
handle_event2({emulator, GL, Chars}, State);
handle_info(_, State) ->
{ok, State}.
-spec handle_call(term(), state()) -> {'ok', {'error', 'bad_query'}, state()}.
handle_call(_Query, State) -> {ok, {error, bad_query}, State}.
-spec terminate(term(), state()) -> {'error_logger', [term()]}.
terminate(swap, {_, 0, Buff}) ->
{error_logger, Buff};
terminate(swap, {_, Lost, Buff}) ->
Myevent = {info, group_leader(), {self(), {lost_messages, Lost}, []}},
{error_logger, [tag_event(Myevent)|Buff]};
terminate(_, _) ->
{error_logger, []}.
handle_event2(Event, {1, Lost, Buff}) ->
display(tag_event(Event)),
{ok, {1, Lost+1, Buff}};
handle_event2(Event, {N, Lost, Buff}) ->
Tagged = tag_event(Event),
display(Tagged),
{ok, {N-1, Lost, [Tagged|Buff]}};
handle_event2(_, State) ->
{ok, State}.
tag_event(Event) ->
{erlang:localtime(), Event}.
display({Tag,{error,_,{_,Format,Args}}}) ->
display2(Tag,Format,Args);
display({Tag,{error_report,_,{_,Type,Report}}}) ->
display2(Tag,Type,Report);
display({Tag,{info_report,_,{_,Type,Report}}}) ->
display2(Tag,Type,Report);
display({Tag,{info,_,{_,Error,_}}}) ->
display2(Tag,Error,[]);
display({Tag,{info_msg,_,{_,Format,Args}}}) ->
display2(Tag,Format,Args);
display({Tag,{warning_report,_,{_,Type,Report}}}) ->
display2(Tag,Type,Report);
display({Tag,{warning_msg,_,{_,Format,Args}}}) ->
display2(Tag,Format,Args);
display({Tag,{emulator,_,Chars}}) ->
display2(Tag,Chars,[]).
add_node(X, Pid) when is_atom(X) ->
add_node(atom_to_list(X), Pid);
add_node(X, Pid) ->
lists:concat([X,"** at node ",node(Pid)," **~n"]).
%% Can't do io_lib:format
display2({{_Y,_Mo,_D},{_H,_Mi,_S}} = Date, F, A) ->
display_date(Date),
display3(string_p(F), F, A).
display_date({{Y,Mo,D},{H,Mi,S}}) ->
erlang:display_string(
integer_to_list(Y) ++ "-" ++
two_digits(Mo) ++ "-" ++
two_digits(D) ++ " " ++
two_digits(H) ++ ":" ++
two_digits(Mi) ++ ":" ++
two_digits(S) ++ " ").
two_digits(N) when 0 =< N, N =< 9 ->
[$0, $0 + N];
two_digits(N) ->
integer_to_list(N).
display3(true, F, A) ->
%% Format string with arguments
erlang:display_string(F ++ "\n"),
[begin
erlang:display_string("\t"),
erlang:display(Arg)
end || Arg <- A],
ok;
display3(false, Atom, A) when is_atom(Atom) ->
%% The widest atom seems to be 'supervisor_report' at 17.
ColumnWidth = 20,
AtomString = atom_to_list(Atom),
AtomLength = length(AtomString),
Padding = lists:duplicate(ColumnWidth - AtomLength, $\s),
erlang:display_string(AtomString ++ Padding),
display4(A);
display3(_, F, A) ->
erlang:display({F, A}).
display4([A, []]) ->
%% Not sure why crash reports look like this.
display4(A);
display4(A = [_|_]) ->
case lists:all(fun({Key,_Value}) -> is_atom(Key); (_) -> false end, A) of
true ->
erlang:display_string("\n"),
lists:foreach(
fun({Key, Value}) ->
erlang:display_string(
" " ++
atom_to_list(Key) ++
": "),
erlang:display(Value)
end, A);
false ->
erlang:display(A)
end;
display4(A) ->
erlang:display(A).
string_p(Term) when is_list(Term) ->
string_p1(lists:flatten(Term));
string_p(_Term) ->
false.
string_p1([]) ->
false;
string_p1(FlatList) ->
io_lib:printable_list(FlatList).
-spec limit_term(term()) -> term().
limit_term(Term) ->
case get_format_depth() of
unlimited -> Term;
D -> io_lib:limit_term(Term, D)
end.
-spec get_format_depth() -> 'unlimited' | pos_integer().
get_format_depth() ->
case application:get_env(kernel, error_logger_format_depth) of
{ok, Depth} when is_integer(Depth) ->
max(10, Depth);
undefined ->
unlimited
end.
