emqx/apps/emqx_machine/src/emqx_machine_terminator.erl

118 lines
3.2 KiB
Erlang

%%--------------------------------------------------------------------
%% Copyright (c) 2021-2023 EMQ Technologies Co., Ltd. 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.
%%--------------------------------------------------------------------
-module(emqx_machine_terminator).
-behaviour(gen_server).
-export([
start_link/0,
graceful/0,
graceful_wait/0,
is_running/0
]).
-export([
init/1,
format_status/2,
handle_cast/2,
handle_call/3,
handle_info/2,
terminate/2,
code_change/3
]).
-include_lib("emqx/include/logger.hrl").
-define(TERMINATOR, ?MODULE).
-define(DO_IT, graceful_shutdown).
%% @doc This API is called to shutdown the Erlang VM by RPC call from remote shell node.
%% The shutdown of apps is delegated to a to a process instead of doing it in the RPC spawned
%% process which has a remote group leader.
start_link() ->
{ok, _} = gen_server:start_link({local, ?TERMINATOR}, ?MODULE, [], []).
is_running() -> is_pid(whereis(?TERMINATOR)).
%% @doc Call `emqx_machine_terminator' to stop applications
%% then call init:stop() stop beam.
graceful() ->
try
_ = gen_server:call(?TERMINATOR, ?DO_IT, infinity)
catch
_:_ ->
%% failed to notify terminator, probably due to not started yet
%% or node is going down, either case, the caller
%% should issue a shutdown to be sure
%% NOTE: not exit_loop here because we do not want to
%% block erl_signal_server
?ELOG("Shutdown before node is ready?~n", []),
init:stop()
end,
ok.
%% @doc Shutdown the Erlang VM and wait indefinitely.
graceful_wait() ->
ok = graceful(),
exit_loop().
exit_loop() ->
timer:sleep(100),
init:stop(),
exit_loop().
init(_) ->
ok = emqx_machine_signal_handler:start(),
{ok, #{}}.
handle_info(_, State) ->
{noreply, State}.
handle_cast(_Cast, State) ->
{noreply, State}.
handle_call(?DO_IT, _From, State) ->
try
%% stop port apps before stopping other apps.
emqx_machine_boot:stop_port_apps(),
emqx_machine_boot:stop_apps()
catch
C:E:St ->
Apps = [element(1, A) || A <- application:which_applications()],
?SLOG(error, #{
msg => "failed_to_stop_apps",
exception => C,
reason => E,
stacktrace => St,
remaining_apps => Apps
})
after
init:stop()
end,
{reply, ok, State};
handle_call(_Call, _From, State) ->
{noreply, State}.
format_status(_Opt, [_Pdict, _S]) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
terminate(_Args, _State) ->
ok.