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Diffstat (limited to 'lib/kernel/src/kernel.erl')
| -rw-r--r-- | lib/kernel/src/kernel.erl | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/lib/kernel/src/kernel.erl b/lib/kernel/src/kernel.erl new file mode 100644 index 0000000000..92ee7b441a --- /dev/null +++ b/lib/kernel/src/kernel.erl @@ -0,0 +1,292 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1996-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% +-module(kernel). + +-behaviour(supervisor). + +%% External exports +-export([start/2, init/1, stop/1]). +-export([config_change/3]). + +%%%----------------------------------------------------------------- +%%% The kernel is the first application started. +%%% Callback functions for the kernel application. +%%%----------------------------------------------------------------- +start(_, []) -> + case supervisor:start_link({local, kernel_sup}, kernel, []) of + {ok, Pid} -> + Type = get_error_logger_type(), + error_logger:swap_handler(Type), + {ok, Pid, []}; + Error -> Error + end. + +stop(_State) -> + ok. + +%%------------------------------------------------------------------- +%% Some configuration parameters for kernel are changed +%%------------------------------------------------------------------- +config_change(Changed, New, Removed) -> + do_distribution_change(Changed, New, Removed), + do_global_groups_change(Changed, New, Removed), + ok. + +get_error_logger_type() -> + case application:get_env(kernel, error_logger) of + {ok, tty} -> tty; + {ok, {file, File}} when is_list(File) -> {logfile, File}; + {ok, false} -> false; + {ok, silent} -> silent; + undefined -> tty; % default value + {ok, Bad} -> exit({bad_config, {kernel, {error_logger, Bad}}}) + end. + +%%%----------------------------------------------------------------- +%%% The process structure in kernel is as shown in the figure. +%%% +%%% --------------- +%%% | kernel_sup (A)| +%%% --------------- +%%% | +%%% ------------------------------- +%%% | | | +%%% <std services> ------------- ------------- +%%% (file,code, | erl_dist (A)| | safe_sup (1)| +%%% rpc, ...) ------------- ------------- +%%% | | +%%% (net_kernel, (disk_log, pg2, +%%% auth, ...) ...) +%%% +%%% The rectangular boxes are supervisors. All supervisors except +%%% for kernel_safe_sup terminates the enitre erlang node if any of +%%% their children dies. Any child that can't be restarted in case +%%% of failure must be placed under one of these supervisors. Any +%%% other child must be placed under safe_sup. These children may +%%% be restarted. Be aware that if a child is restarted the old state +%%% and all data will be lost. +%%%----------------------------------------------------------------- +%%% Callback functions for the kernel_sup supervisor. +%%%----------------------------------------------------------------- + +init([]) -> + SupFlags = {one_for_all, 0, 1}, + + Config = {kernel_config, + {kernel_config, start_link, []}, + permanent, 2000, worker, [kernel_config]}, + Code = {code_server, + {code, start_link, get_code_args()}, + permanent, 2000, worker, [code]}, + File = {file_server_2, + {file_server, start_link, []}, + permanent, 2000, worker, + [file, file_server, file_io_server, prim_file]}, + StdError = {standard_error, + {standard_error, start_link, []}, + temporary, 2000, supervisor, [user_sup]}, + User = {user, + {user_sup, start, []}, + temporary, 2000, supervisor, [user_sup]}, + + case init:get_argument(mode) of + {ok, [["minimal"]]} -> + SafeSupervisor = {kernel_safe_sup, + {supervisor, start_link, + [{local, kernel_safe_sup}, ?MODULE, safe]}, + permanent, infinity, supervisor, [?MODULE]}, + {ok, {SupFlags, + [File, Code, StdError, User, + Config, SafeSupervisor]}}; + _ -> + Rpc = {rex, {rpc, start_link, []}, + permanent, 2000, worker, [rpc]}, + Global = {global_name_server, {global, start_link, []}, + permanent, 2000, worker, [global]}, + Glo_grp = {global_group, {global_group,start_link,[]}, + permanent, 2000, worker, [global_group]}, + InetDb = {inet_db, {inet_db, start_link, []}, + permanent, 2000, worker, [inet_db]}, + NetSup = {net_sup, {erl_distribution, start_link, []}, + permanent, infinity, supervisor,[erl_distribution]}, + DistAC = start_dist_ac(), + + Timer = start_timer(), + + SafeSupervisor = {kernel_safe_sup, + {supervisor, start_link, + [{local, kernel_safe_sup}, ?MODULE, safe]}, + permanent, infinity, supervisor, [?MODULE]}, + {ok, {SupFlags, + [Rpc, Global, InetDb | DistAC] ++ + [NetSup, Glo_grp, File, Code, + StdError, User, Config, SafeSupervisor] ++ Timer}} + end; +init(safe) -> + SupFlags = {one_for_one, 4, 3600}, + Boot = start_boot_server(), + DiskLog = start_disk_log(), + Pg2 = start_pg2(), + {ok, {SupFlags, Boot ++ DiskLog ++ Pg2}}. + +get_code_args() -> + case init:get_argument(nostick) of + {ok, [[]]} -> [[nostick]]; + _ -> [] + end. + +start_dist_ac() -> + Spec = [{dist_ac,{dist_ac,start_link,[]},permanent,2000,worker,[dist_ac]}], + case application:get_env(kernel, start_dist_ac) of + {ok, true} -> Spec; + {ok, false} -> []; + undefined -> + case application:get_env(kernel, distributed) of + {ok, _} -> Spec; + _ -> [] + end + end. + +start_boot_server() -> + case application:get_env(kernel, start_boot_server) of + {ok, true} -> + Args = get_boot_args(), + [{boot_server, {erl_boot_server, start_link, [Args]}, permanent, + 1000, worker, [erl_boot_server]}]; + _ -> + [] + end. + +get_boot_args() -> + case application:get_env(kernel, boot_server_slaves) of + {ok, Slaves} -> Slaves; + _ -> [] + end. + +start_disk_log() -> + case application:get_env(kernel, start_disk_log) of + {ok, true} -> + [{disk_log_server, + {disk_log_server, start_link, []}, + permanent, 2000, worker, [disk_log_server]}, + {disk_log_sup, {disk_log_sup, start_link, []}, permanent, + 1000, supervisor, [disk_log_sup]}]; + _ -> + [] + end. + +start_pg2() -> + case application:get_env(kernel, start_pg2) of + {ok, true} -> + [{pg2, {pg2, start_link, []}, permanent, 1000, worker, [pg2]}]; + _ -> + [] + end. + +start_timer() -> + case application:get_env(kernel, start_timer) of + {ok, true} -> + [{timer_server, {timer, start_link, []}, permanent, 1000, worker, + [timer]}]; + _ -> + [] + end. + +%%----------------------------------------------------------------- +%% The change of the distributed parameter is taken care of here +%%----------------------------------------------------------------- +do_distribution_change(Changed, New, Removed) -> + %% check if the distributed parameter is changed. It is not allowed + %% to make a local application to a distributed one, or vice versa. + case is_dist_changed(Changed, New, Removed) of + %%{changed, new, removed} + {false, false, false} -> + ok; + {C, false, false} -> + %% At last, update the parameter. + gen_server:call(dist_ac, {distribution_changed, C}, infinity); + {false, _, false} -> + error_logger:error_report("Distribution not changed: " + "Not allowed to add the 'distributed' " + "parameter."), + {error, {distribution_not_changed, "Not allowed to add the " + "'distributed' parameter"}}; + {false, false, _} -> + error_logger:error_report("Distribution not changed: " + "Not allowed to remove the " + "distribution parameter."), + {error, {distribution_not_changed, "Not allowed to remove the " + "'distributed' parameter"}} + end. + +%%----------------------------------------------------------------- +%% Check if distribution is changed in someway. +%%----------------------------------------------------------------- +is_dist_changed(Changed, New, Removed) -> + C = case lists:keyfind(distributed, 1, Changed) of + false -> + false; + {distributed, NewDistC} -> + NewDistC + end, + N = case lists:keyfind(distributed, 1, New) of + false -> + false; + {distributed, NewDistN} -> + NewDistN + end, + R = lists:member(distributed, Removed), + {C, N, R}. + +%%----------------------------------------------------------------- +%% The change of the global_groups parameter is taken care of here +%%----------------------------------------------------------------- +do_global_groups_change(Changed, New, Removed) -> + %% check if the global_groups parameter is changed. + case is_gg_changed(Changed, New, Removed) of + %%{changed, new, removed} + {false, false, false} -> + ok; + {C, false, false} -> + %% At last, update the parameter. + global_group:global_groups_changed(C); + {false, N, false} -> + global_group:global_groups_added(N); + {false, false, R} -> + global_group:global_groups_removed(R) + end. + +%%----------------------------------------------------------------- +%% Check if global_groups is changed in someway. +%%----------------------------------------------------------------- +is_gg_changed(Changed, New, Removed) -> + C = case lists:keyfind(global_groups, 1, Changed) of + false -> + false; + {global_groups, NewDistC} -> + NewDistC + end, + N = case lists:keyfind(global_groups, 1, New) of + false -> + false; + {global_groups, NewDistN} -> + NewDistN + end, + R = lists:member(global_groups, Removed), + {C, N, R}. |