%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2017. 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(mnesia_event).
-behaviour(gen_event).
%-behaviour(mnesia_event).
%% gen_event callback interface
-export([init/1,
handle_event/2,
handle_call/2,
handle_info/2,
terminate/2,
code_change/3]).
-record(state, {nodes = [],
dumped_core = false, %% only dump fatal core once
args}).
%%%----------------------------------------------------------------
%%% Callback functions from gen_server
%%%----------------------------------------------------------------
%%-----------------------------------------------------------------
%% init(Args) ->
%% {ok, State} | Error
%%-----------------------------------------------------------------
init(Args) ->
{ok, #state{args = Args}}.
%%-----------------------------------------------------------------
%% handle_event(Event, State) ->
%% {ok, NewState} | remove_handler |
%% {swap_handler, Args1, State1, Mod2, Args2}
%%-----------------------------------------------------------------
handle_event(Event, State) ->
handle_any_event(Event, State).
%%-----------------------------------------------------------------
%% handle_info(Msg, State) ->
%% {ok, NewState} | remove_handler |
%% {swap_handler, Args1, State1, Mod2, Args2}
%%-----------------------------------------------------------------
handle_info(Msg, State) ->
{ok, _} = handle_any_event(Msg, State),
{ok, State}.
%%-----------------------------------------------------------------
%% handle_call(Event, State) ->
%% {ok, Reply, NewState} | {remove_handler, Reply} |
%% {swap_handler, Reply, Args1, State1, Mod2, Args2}
%%-----------------------------------------------------------------
handle_call(Msg, State) ->
Reply = ok,
{ok, NewState} = handle_any_event(Msg, State),
{ok, Reply, NewState}.
%%-----------------------------------------------------------------
%% terminate(Reason, State) ->
%% AnyVal
%%-----------------------------------------------------------------
terminate(_Reason, _State) ->
ok.
%%----------------------------------------------------------------------
%% Func: code_change/3
%% Purpose: Upgrade process when its code is to be changed
%% Returns: {ok, NewState}
%%----------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%-----------------------------------------------------------------
%% Internal functions
%%-----------------------------------------------------------------
handle_any_event({mnesia_system_event, Event}, State) ->
handle_system_event(Event, State);
handle_any_event({mnesia_table_event, Event}, State) ->
handle_table_event(Event, State);
handle_any_event(Msg, State) ->
report_error("~p got unexpected event: ~p~n", [?MODULE, Msg]),
{ok, State}.
handle_table_event({Oper, Record, TransId}, State) ->
report_info("~p performed by ~p on record:~n\t~p~n",
[Oper, TransId, Record]),
{ok, State}.
handle_system_event({mnesia_checkpoint_activated, _Checkpoint}, State) ->
{ok, State};
handle_system_event({mnesia_checkpoint_deactivated, Checkpoint}, State) ->
report_error("Checkpoint '~p' has been deactivated, last table copy deleted.\n",[Checkpoint]),
{ok, State};
handle_system_event({mnesia_up, Node}, State) ->
Nodes = [Node | State#state.nodes],
{ok, State#state{nodes = Nodes}};
handle_system_event({mnesia_down, Node}, State) ->
case mnesia:system_info(fallback_activated) andalso Node =/= node() of
true ->
case mnesia_monitor:get_env(fallback_error_function) of
{mnesia, lkill} ->
Msg = "A fallback is installed and Mnesia "
"must be restarted. Forcing shutdown "
"after mnesia_down from ~p...~n",
report_fatal(Msg, [Node], nocore, State#state.dumped_core),
catch exit(whereis(mnesia_monitor), fatal),
{ok, State};
{UserMod, UserFunc} ->
Msg = "Warning: A fallback is installed and Mnesia got mnesia_down "
"from ~p. ~n",
report_info(Msg, [Node]),
case catch apply(UserMod, UserFunc, [Node]) of
{'EXIT', {undef, _Reason}} ->
%% Backward compatibility
apply(UserMod, UserFunc, []);
{'EXIT', Reason} ->
exit(Reason);
_ ->
ok
end,
Nodes = lists:delete(Node, State#state.nodes),
{ok, State#state{nodes = Nodes}}
end;
false ->
Nodes = lists:delete(Node, State#state.nodes),
{ok, State#state{nodes = Nodes}}
end;
handle_system_event({mnesia_overload, Details}, State) ->
report_warning("Mnesia is overloaded: ~w~n", [Details]),
{ok, State};
handle_system_event({mnesia_info, Format, Args}, State) ->
report_info(Format, Args),
{ok, State};
handle_system_event({mnesia_warning, Format, Args}, State) ->
report_warning(Format, Args),
{ok, State};
handle_system_event({mnesia_error, Format, Args}, State) ->
report_error(Format, Args),
{ok, State};
handle_system_event({mnesia_fatal, Format, Args, BinaryCore}, State) ->
report_fatal(Format, Args, BinaryCore, State#state.dumped_core),
{ok, State#state{dumped_core = true}};
handle_system_event({inconsistent_database, Reason, Node}, State) ->
report_error("mnesia_event got {inconsistent_database, ~w, ~w}~n",
[Reason, Node]),
{ok, State};
handle_system_event({mnesia_user, Event}, State) ->
report_info("User event: ~p~n", [Event]),
{ok, State};
handle_system_event(Msg, State) ->
report_error("mnesia_event got unexpected system event: ~p~n", [Msg]),
{ok, State}.
report_info(Format0, Args0) ->
Format = "Mnesia(~p): " ++ Format0,
Args = [node() | Args0],
case global:whereis_name(mnesia_global_logger) of
undefined ->
io:format(Format, Args);
Pid ->
io:format(Pid, Format, Args)
end.
report_warning(Format0, Args0) ->
Format = "Mnesia(~p): ** WARNING ** " ++ Format0,
Args = [node() | Args0],
case erlang:function_exported(error_logger, warning_msg, 2) of
true ->
error_logger:warning_msg(Format, Args);
false ->
error_logger:format(Format, Args)
end,
case global:whereis_name(mnesia_global_logger) of
undefined ->
ok;
Pid ->
io:format(Pid, Format, Args)
end.
report_error(Format0, Args0) ->
Format = "Mnesia(~p): ** ERROR ** " ++ Format0,
Args = [node() | Args0],
error_logger:format(Format, Args),
case global:whereis_name(mnesia_global_logger) of
undefined ->
ok;
Pid ->
io:format(Pid, Format, Args)
end.
report_fatal(Format, Args, BinaryCore, CoreDumped) ->
UseDir = mnesia_monitor:use_dir(),
CoreDir = mnesia_monitor:get_env(core_dir),
if
is_list(CoreDir),CoreDumped == false, is_binary(BinaryCore) ->
core_file(CoreDir,BinaryCore,Format,Args);
(UseDir == true),CoreDumped == false, is_binary(BinaryCore) ->
core_file(CoreDir,BinaryCore,Format,Args);
true ->
report_error("(ignoring core) ** FATAL ** " ++ Format, Args)
end.
core_file(CoreDir,BinaryCore,Format,Args) ->
Integers = tuple_to_list(erlang:timestamp()),
Fun = fun(I) when I < 10 -> ["_0",I];
(I) -> ["_",I]
end,
List = lists:append([Fun(I) || I <- Integers]),
CoreFile = if is_list(CoreDir) ->
filename:absname(lists:concat(["MnesiaCore.", node()] ++ List),
CoreDir);
true ->
filename:absname(lists:concat(["MnesiaCore.", node()] ++ List))
end,
case file:write_file(CoreFile, BinaryCore) of
ok ->
report_error("(core dumped to file: ~p)~n ** FATAL ** " ++ Format,
[CoreFile] ++ Args);
{error, Reason} ->
report_error("(could not write core file: ~p)~n ** FATAL ** " ++ Format,
[Reason] ++ Args)
end.
