%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2009. 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(erl_distribution).
-behaviour(supervisor).
-export([start_link/0,start_link/1,init/1,start/1,stop/0]).
-define(DBG,erlang:display([?MODULE,?LINE])).
%% Called during system start-up.
start_link() ->
case catch start_p() of
{ok,Args} ->
start_link(Args);
_ ->
ignore
end.
%% Called from net_kernel:start/1 to start distribution after the
%% system has already started.
start(Args) ->
C = {net_sup_dynamic, {?MODULE,start_link,[Args]}, permanent,
1000, supervisor, [erl_distribution]},
supervisor:start_child(kernel_sup, C).
%% Stop distribution.
stop() ->
case supervisor:terminate_child(kernel_sup, net_sup_dynamic) of
ok ->
supervisor:delete_child(kernel_sup, net_sup_dynamic);
Error ->
case whereis(net_sup) of
Pid when is_pid(Pid) ->
%% Dist. started through -sname | -name flags
{error, not_allowed};
_ ->
Error
end
end.
%%%
%%% Internal helper functions.
%%%
%% Helper start function.
start_link(Args) ->
supervisor:start_link({local,net_sup}, ?MODULE, Args).
init(NetArgs) ->
Epmd =
case init:get_argument(no_epmd) of
{ok, [[]]} ->
[];
_ ->
EpmdMod = net_kernel:epmd_module(),
[{EpmdMod,{EpmdMod,start_link,[]},
permanent,2000,worker,[EpmdMod]}]
end,
Auth = {auth,{auth,start_link,[]},permanent,2000,worker,[auth]},
Kernel = {net_kernel,{net_kernel,start_link,[NetArgs]},
permanent,2000,worker,[net_kernel]},
EarlySpecs = net_kernel:protocol_childspecs(),
{ok,{{one_for_all,0,1}, EarlySpecs ++ Epmd ++ [Auth,Kernel]}}.
start_p() ->
sname(),
lname(),
false.
sname() ->
case init:get_argument(sname) of
{ok,[[Name]]} ->
throw({ok,[list_to_atom(Name),shortnames|ticktime()]});
_ ->
false
end.
lname() ->
case init:get_argument(name) of
{ok,[[Name]]} ->
throw({ok,[list_to_atom(Name),longnames|ticktime()]});
_ ->
false
end.
ticktime() ->
%% catch, in case the system was started with boot file start_old,
%% i.e. running without the application_controller.
%% Time is given in seconds. The net_kernel tick time is
%% Time/4 milliseconds.
case catch application:get_env(net_ticktime) of
{ok, Value} when is_integer(Value), Value > 0 ->
[Value * 250]; %% i.e. 1000 / 4 = 250 ms.
_ ->
[]
end.
