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diff --git a/lib/kernel/src/logger_simple.erl b/lib/kernel/src/logger_simple.erl
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+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 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(logger_simple).
+
+-export([adding_handler/2, removing_handler/1, log/2]).
+-export([get_buffer/0]).
+
+%% This module implements a simple handler for logger. It is the
+%% default used during system start.
+
+%%%-----------------------------------------------------------------
+%%% API
+get_buffer() ->
+ case whereis(?MODULE) of
+ undefined ->
+ {error,noproc};
+ Pid ->
+ Ref = erlang:monitor(process,Pid),
+ Pid ! {get_buffer,self()},
+ receive
+ {buffer,Buffer} ->
+ erlang:demonitor(Ref,[flush]),
+ {ok,Buffer};
+ {'DOWN',Ref,process,Pid,Reason} ->
+ {error,Reason}
+ end
+ end.
+
+%%%-----------------------------------------------------------------
+%%% Logger callback
+
+adding_handler(?MODULE,Config) ->
+ Me = self(),
+ case whereis(?MODULE) of
+ undefined ->
+ {Pid,Ref} = spawn_opt(fun() -> init(Me,Config) end,
+ [link,monitor,{message_queue_data,off_heap}]),
+ receive
+ {'DOWN',Ref,process,Pid,Reason} ->
+ {error,Reason};
+ {Pid,started} ->
+ erlang:demonitor(Ref),
+ {ok,Config}
+ end;
+ _ ->
+ {error,{handler_process_name_already_exists,?MODULE}}
+ end.
+
+removing_handler(?MODULE) ->
+ case whereis(?MODULE) of
+ undefined ->
+ ok;
+ Pid ->
+ Ref = erlang:monitor(process,Pid),
+ unlink(Pid),
+ Pid ! stop,
+ receive {'DOWN',Ref,process,Pid,_} ->
+ ok
+ end
+ end.
+
+log(#{meta:=#{error_logger:=#{tag:=info_report,type:=Type}}},_Config)
+ when Type=/=std_info ->
+ %% Skip info reports that are not 'std_info' (ref simple logger in
+ %% error_logger)
+ ok;
+log(#{msg:=_,meta:=#{time:=_}}=Log,_Config) ->
+ _ = case whereis(?MODULE) of
+ undefined ->
+ %% Is the node on the way down? Real emergency?
+ %% Log directly from client just to get it out
+ do_log(
+ #{level=>error,
+ msg=>{report,{error,simple_handler_process_dead}},
+ meta=>#{time=>erlang:monotonic_time(microsecond)}}),
+ do_log(Log);
+ _ ->
+ ?MODULE ! {log,Log}
+ end,
+ ok;
+log(_,_) ->
+ %% Unexpected log.
+ %% We don't want to crash the simple logger, so ignore this.
+ ok.
+
+%%%-----------------------------------------------------------------
+%%% Process
+init(Starter,Config) ->
+ register(?MODULE,self()),
+ Starter ! {self(),started},
+ BufferSize =
+ case Config of
+ #{?MODULE:=#{buffer:=true}} ->
+ 10;
+ _ ->
+ infinity
+ end,
+ loop(#{buffer_size=>BufferSize,dropped=>0,buffer=>[]},infinity).
+
+loop(Buffer,Timeout) ->
+ receive
+ stop ->
+ ok;
+ {get_buffer,From} ->
+ loop(Buffer#{send_to=>From},0);
+ {log,#{msg:=_,meta:=#{time:=_}}=Log} ->
+ do_log(Log),
+ loop(update_buffer(Buffer,Log),Timeout);
+ _ ->
+ %% Unexpected message - flush it!
+ loop(Buffer,Timeout)
+ after Timeout ->
+ #{dropped:=D,buffer:=B,send_to:=Pid} = Buffer,
+ LogList = lists:reverse(B) ++ drop_msg(D),
+ Pid ! {buffer,LogList},
+ loop(Buffer#{buffer_size=>infinity,
+ dropped=>0,
+ buffer=>[],
+ send_to=>false},
+ infinity)
+ end.
+
+update_buffer(#{buffer_size:=infinity}=Buffer,_Log) ->
+ Buffer;
+update_buffer(#{buffer_size:=0,dropped:=D}=Buffer,_Log) ->
+ Buffer#{dropped=>D+1};
+update_buffer(#{buffer_size:=S,buffer:=B}=Buffer,Log) ->
+ Buffer#{buffer_size=>S-1,buffer=>[Log|B]}.
+
+drop_msg(0) ->
+ [];
+drop_msg(N) ->
+ [#{level=>info,
+ msg=>{"Simple handler buffer full, dropped ~w messages",[N]},
+ meta=>#{time=>erlang:monotonic_time(microsecond)}}].
+
+%%%-----------------------------------------------------------------
+%%% Internal
+
+%% Can't do io_lib:format
+
+do_log(#{msg:={report,Report},
+ meta:=#{time:=T,error_logger:=#{type:=Type}}}) ->
+ display_date(T),
+ display_report(Type,Report);
+do_log(#{msg:=Msg,meta:=#{time:=T}}) ->
+ %% Maybe buffer event - if next handler shall be able to
+ %% re-display it
+ display_date(T),
+ display(Msg).
+
+display_date(Timestamp0) when is_integer(Timestamp0) ->
+ Timestamp = Timestamp0 + erlang:time_offset(microsecond),
+ Micro = Timestamp rem 1000000,
+ Sec = Timestamp div 1000000,
+ {{Y,Mo,D},{H,Mi,S}} = erlang:universaltime_to_localtime(
+ erlang:posixtime_to_universaltime(Sec)),
+ erlang:display_string(
+ integer_to_list(Y) ++ "-" ++
+ pad(Mo,2) ++ "-" ++
+ pad(D,2) ++ " " ++
+ pad(H,2) ++ ":" ++
+ pad(Mi,2) ++ ":" ++
+ pad(S,2) ++ "." ++
+ pad(Micro,6) ++ " ").
+
+pad(Int,Size) when is_integer(Int) ->
+ pad(integer_to_list(Int),Size);
+pad(Str,Size) when length(Str)==Size ->
+ Str;
+pad(Str,Size) ->
+ pad([$0|Str],Size).
+
+display({string,Chardata}) ->
+ try unicode:characters_to_list(Chardata) of
+ String -> erlang:display_string(String), erlang:display_string("\n")
+ catch _:_ -> erlang:display(Chardata)
+ end;
+display({report,Report}) when is_map(Report) ->
+ display_report(maps:to_list(Report));
+display({report,Report}) ->
+ display_report(Report);
+display({F, A}) when is_list(F), is_list(A) ->
+ erlang:display_string(F ++ "\n"),
+ [begin
+ erlang:display_string("\t"),
+ erlang:display(Arg)
+ end || Arg <- A],
+ ok.
+
+display_report(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),
+ display_report(A);
+display_report(F, A) ->
+ erlang:display({F, A}).
+
+display_report([A, []]) ->
+ %% Special case for crash reports when process has no links
+ display_report(A);
+display_report(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;
+display_report(A) ->
+ erlang:display(A).