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%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2018. 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(kernel_config).
-behaviour(gen_server).
%% External exports
-export([start_link/0]).
%% Internal exports
-export([init/1, handle_info/2, terminate/2, send_timeout/2]).
-export([handle_call/3, handle_cast/2, code_change/3]).
%%%-----------------------------------------------------------------
%%% This module implements a process that configures the kernel
%%% application.
%%% Its purpose is that in the init phase waits for other nodes at startup,
%%% if specified.
%%%-----------------------------------------------------------------
start_link() -> gen_server:start_link(kernel_config, [], []).
%%-----------------------------------------------------------------
%% Callback functions from gen_server
%%-----------------------------------------------------------------
-spec init([]) -> {'ok', []} | {'stop', term()}.
init([]) ->
process_flag(trap_exit, true),
case sync_nodes() of
ok ->
case whereis(dist_ac) of
DAC when is_pid(DAC) ->
DAC ! {go, self()},
receive
dist_ac_took_control ->
ok
end;
_ ->
ok
end,
{ok, []};
{error, Error} ->
{stop, Error}
end.
-spec handle_info(term(), State) -> {'noreply', State}.
handle_info(_, State) ->
{noreply, State}.
-spec terminate(term(), term()) -> 'ok'.
terminate(_Reason, _State) ->
ok.
-spec handle_call(term(), term(), State) -> {'reply', 'ok', State}.
handle_call('__not_used', _From, State) ->
{reply, ok, State}.
-spec handle_cast(term(), State) -> {'noreply', State}.
handle_cast('__not_used', State) ->
{noreply, State}.
-spec code_change(term(), State, term()) -> {'ok', State}.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%-----------------------------------------------------------------
%% Internal functions
%%-----------------------------------------------------------------
sync_nodes() ->
case catch get_sync_data() of
{error, Reason} = Error ->
error_logger:format("~tp", [Reason]),
Error;
{infinity, MandatoryNodes, OptionalNodes} ->
case wait_nodes(MandatoryNodes, OptionalNodes) of
ok ->
% sync(),
ok;
Error ->
Error
end;
{Timeout, MandatoryNodes, OptionalNodes} ->
spawn_link(kernel_config, send_timeout, [Timeout, self()]),
case wait_nodes(MandatoryNodes, OptionalNodes) of
ok ->
% sync(),
ok;
Error ->
Error
end;
undefined -> ok
end.
send_timeout(Timeout, Pid) ->
receive
after Timeout -> Pid ! timeout
end.
wait_nodes(Mandatory, Optional) ->
ok = net_kernel:monitor_nodes(true),
lists:foreach(fun(Node) ->
case net_adm:ping(Node) of
pong -> self() ! {nodeup, Node};
_ -> ok
end
end,
Mandatory ++ Optional),
R = rec_nodes(Mandatory, Optional),
ok = net_kernel:monitor_nodes(false),
R.
rec_nodes([], []) -> ok;
rec_nodes(Mandatory, Optional) ->
receive
{nodeup, Node} -> check_up(Node, Mandatory, Optional);
timeout when Mandatory =:= [] -> ok;
timeout -> {error, {mandatory_nodes_down, Mandatory}}
end.
check_up(Node, Mandatory, Optional) ->
case lists:member(Node, Mandatory) of
true ->
rec_nodes(lists:delete(Node, Mandatory), Optional);
false ->
case lists:member(Node, Optional) of
true ->
rec_nodes(Mandatory, lists:delete(Node, Optional));
false ->
rec_nodes(Mandatory, Optional)
end
end.
%% Syncs standard servers
%sync() ->
% global:sync().
get_sync_data() ->
Timeout = get_sync_timeout(),
MandatoryNodes = get_sync_mandatory_nodes(),
OptionalNodes = get_sync_optional_nodes(),
{Timeout, MandatoryNodes, OptionalNodes}.
get_sync_timeout() ->
case application:get_env(sync_nodes_timeout) of
{ok, Timeout} when is_integer(Timeout), Timeout > 0 -> Timeout;
{ok, infinity} -> infinity;
undefined -> throw(undefined);
{ok, Else} -> throw({error, {badopt, {sync_nodes_timeout, Else}}})
end.
get_sync_mandatory_nodes() ->
case application:get_env(sync_nodes_mandatory) of
{ok, Nodes} when is_list(Nodes) -> Nodes;
undefined -> [];
{ok, Else} -> throw({error, {badopt, {sync_nodes_mandatory, Else}}})
end.
get_sync_optional_nodes() ->
case application:get_env(sync_nodes_optional) of
{ok, Nodes} when is_list(Nodes) -> Nodes;
undefined -> [];
{ok, Else} -> throw({error, {badopt, {sync_nodes_optional, Else}}})
end.
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