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Diffstat (limited to 'lib/kernel/src/global_search.erl')
| -rw-r--r-- | lib/kernel/src/global_search.erl | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/lib/kernel/src/global_search.erl b/lib/kernel/src/global_search.erl new file mode 100644 index 0000000000..b723e18a1b --- /dev/null +++ b/lib/kernel/src/global_search.erl @@ -0,0 +1,279 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1998-2009. 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(global_search). + +%% Search for globally registered names in the global groups. +%% This is a help module to the global_group.erl + + +%% External exports +-export([start/2]). +-export([init_send/1]). +-export([init_whereis/1]). +-export([init_names/1]). + + +%% ONLY for test purpose +-export([send_test/1]). +-export([whereis_test/1]). +-export([names_test/1]). + + + + +%%%==================================================================================== +%%% The search is done in a process separate from the global_group process +%%%==================================================================================== +start(Flag, Arg) -> + case Flag of + send -> + spawn_link(?MODULE, init_send, [Arg]); + whereis -> + spawn_link(?MODULE, init_whereis, [Arg]); + names -> + spawn_link(?MODULE, init_names, [Arg]); + %% ONLY for test suites, tests what happens when this process exits. + send_test -> + spawn_link(?MODULE, send_test, [Arg]); + whereis_test -> + spawn_link(?MODULE, whereis_test, [Arg]); + names_test -> + spawn_link(?MODULE, names_test, [Arg]) + end. + + +%%%==================================================================================== +%%%==================================================================================== +%%%==================================================================================== +%%% Search after a registered global Name anywhere (any), in a specified group or +%%% in a specified node. +%%% Return the result to the global_group process in own node and wait for +%%% this process to be killed. +%%%==================================================================================== +%%%==================================================================================== +%%%==================================================================================== + +init_send({any, NodesList, Name, Msg, From}) -> + case whereis_any_loop(NodesList, Name) of + undefined -> + Res = {badarg,{Name, Msg}}, + gen_server:cast(global_group, {send_res, Res, Name, Msg, self(), From}); + Pid -> + gen_server:cast(global_group, {send_res, Pid, Name, Msg, self(), From}) + end, + end_loop(); +init_send({group, Nodes, Name, Msg, From}) -> + case whereis_group_loop(Nodes, Name) of + group_down -> + Res = {badarg,{Name, Msg}}, + gen_server:cast(global_group, {send_res, Res, Name, Msg, self(), From}); + undefined -> + Res = {badarg,{Name, Msg}}, + gen_server:cast(global_group, {send_res, Res, Name, Msg, self(), From}); + Pid -> + gen_server:cast(global_group, {send_res, Pid, Name, Msg, self(), From}) + end, + end_loop(); +init_send({node, Node, Name, Msg, From}) -> + case whereis_check_node(Node, Name) of + node_down -> + Res = {badarg,{Name, Msg}}, + gen_server:cast(global_group, {send_res, Res, Name, Msg, self(), From}); + undefined -> + Res = {badarg,{Name, Msg}}, + gen_server:cast(global_group, {send_res, Res, Name, Msg, self(), From}); + Pid -> + gen_server:cast(global_group, {send_res, Pid, Name, Msg, self(), From}) + end, + end_loop(). + + +%%%==================================================================================== +%%%==================================================================================== +%%%==================================================================================== +%%% Search after a registered global Name anywhere (any), in a specified group or +%%% in a specified node. +%%% Return the result to the global_group process in own node and wait for +%%% this process to be killed. +%%%==================================================================================== +%%%==================================================================================== +%%%==================================================================================== + +init_whereis({any, NodesList, Name, From}) -> + R = whereis_any_loop(NodesList, Name), + gen_server:cast(global_group, {find_name_res, R, self(), From}), + end_loop(); +init_whereis({group, Nodes, Name, From}) -> + case whereis_group_loop(Nodes, Name) of + group_down -> + gen_server:cast(global_group, {find_name_res, undefined, self(), From}); + R -> + gen_server:cast(global_group, {find_name_res, R, self(), From}) + end, + end_loop(); +init_whereis({node, Node, Name, From}) -> + case whereis_check_node(Node, Name) of + node_down -> + gen_server:cast(global_group, {find_name_res, undefined, self(), From}); + R -> + gen_server:cast(global_group, {find_name_res, R, self(), From}) + end, + end_loop(). + + +%%%==================================================================================== +%%%==================================================================================== +%%%==================================================================================== +%%% Get the registered names, in a specified group or in a specified node. +%%% Return the result to the global_group process in own node and wait for +%%% this process to be killed. +%%%==================================================================================== +%%%==================================================================================== +%%%==================================================================================== +init_names({group, Nodes, From}) -> + case names_group_loop(Nodes) of + group_down -> + gen_server:cast(global_group, {registered_names_res, [], self(), From}); + R -> + gen_server:cast(global_group, {registered_names_res, R, self(), From}) + end, + end_loop(); +init_names({node, Node, From}) -> + case names_check_node(Node) of + node_down -> + gen_server:cast(global_group, {registered_names_res, [], self(), From}); + R -> + gen_server:cast(global_group, {registered_names_res, R, self(), From}) + end, + end_loop(). + +%%%==================================================================================== +%%% Wait for the kill message. +%%%==================================================================================== + +-spec end_loop() -> no_return(). + +end_loop() -> + receive + kill -> + exit(normal) + end. + +%%%==================================================================================== +%%% Search for the globally registered name in the whole known world. +%%%==================================================================================== +whereis_any_loop([], _Name) -> + undefined; +whereis_any_loop([{_Group_name, Nodes}|T], Name) -> + case whereis_group_loop(Nodes, Name) of + group_down -> + whereis_any_loop(T, Name); + undefined -> + whereis_any_loop(T, Name); + R -> + R + end. + +%%%==================================================================================== +%%% Search for the globally registered name in a specified global group. +%%%==================================================================================== +whereis_group_loop([], _Name) -> + group_down; +whereis_group_loop([Node|T], Name) -> + case whereis_check_node(Node, Name) of + node_down -> + whereis_group_loop(T, Name); + R -> + R + end. +%%%==================================================================================== +%%% Search for the globally registered name on a specified node. +%%%==================================================================================== +whereis_check_node(Node, Name) -> + case net_adm:ping(Node) of + pang -> + node_down; + pong -> + monitor_node(Node, true), + gen_server:cast({global_group, Node},{find_name, self(), Name}), + receive + {nodedown, Node} -> + node_down; + {find_name_res, Result} -> + monitor_node(Node, false), + Result + end + end. + + + + +%%%==================================================================================== +%%% Search for all globally registered name in a specified global group. +%%%==================================================================================== +names_group_loop([]) -> + group_down; +names_group_loop([Node|T]) -> + case names_check_node(Node) of + node_down -> + names_group_loop(T); + R -> + R + end. +%%%==================================================================================== +%%% Search for all globally registered name on a specified node. +%%%==================================================================================== +names_check_node(Node) -> + case net_adm:ping(Node) of + pang -> + node_down; + pong -> + monitor_node(Node, true), + gen_server:cast({global_group, Node},{registered_names, self()}), + receive + {nodedown, Node} -> + node_down; + {registered_names_res, Result} -> + monitor_node(Node, false), + Result + end + end. + + + + + + +%%%==================================================================================== +%%% Test what happens when this process exits. +%%%==================================================================================== +send_test(_Args) -> + timer:sleep(5000), + exit(testing_exit). + +whereis_test(_Args) -> + timer:sleep(5000), + exit(testing_exit). + +names_test(_Args) -> + timer:sleep(5000), + exit(testing_exit). + + + |