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author | Anders Svensson <[email protected]> | 2011-05-18 18:58:01 +0200 |
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committer | Anders Svensson <[email protected]> | 2011-05-18 18:58:01 +0200 |
commit | 1756ed583f24ba2206a0f573635a6fa3cdea5c54 (patch) | |
tree | c762a6e700f09fb580f8c9945fd6886ecc2c9923 /lib/diameter/src/app/diameter_reg.erl | |
parent | e993da4426a76bb172290a10999267d3023120d5 (diff) | |
parent | 3c15ff32e89e401b4dde2b8acc9699be2614b996 (diff) | |
download | otp-1756ed583f24ba2206a0f573635a6fa3cdea5c54.tar.gz otp-1756ed583f24ba2206a0f573635a6fa3cdea5c54.tar.bz2 otp-1756ed583f24ba2206a0f573635a6fa3cdea5c54.zip |
Merge branch 'anders/diameter_import/OTP-9321' into dev
* anders/diameter_import/OTP-9321:
Initial commit of the diameter application.
Diffstat (limited to 'lib/diameter/src/app/diameter_reg.erl')
-rw-r--r-- | lib/diameter/src/app/diameter_reg.erl | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/lib/diameter/src/app/diameter_reg.erl b/lib/diameter/src/app/diameter_reg.erl new file mode 100644 index 0000000000..8e5f34c2c3 --- /dev/null +++ b/lib/diameter/src/app/diameter_reg.erl @@ -0,0 +1,331 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2010-2011. 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% +%% + +%% +%% The module implements a simple term -> pid registry. +%% + +-module(diameter_reg). +-compile({no_auto_import, [monitor/2]}). + +-behaviour(gen_server). + +-export([add/1, + add_new/1, + del/1, + repl/2, + match/1]). + +-export([start_link/0]). + +%% gen_server callbacks +-export([init/1, + terminate/2, + handle_call/3, + handle_cast/2, + handle_info/2, + code_change/3]). + +%% test +-export([pids/0, + terms/0]). + +%% debug +-export([state/0, + uptime/0]). + +-include("diameter_internal.hrl"). + +-define(SERVER, ?MODULE). +-define(TABLE, ?MODULE). + +%% Table entry used to keep from starting more than one monitor on the +%% same process. This isn't a problem but there's no point in starting +%% multiple monitors if we can avoid it. Note that we can't have a 2-tuple +%% keyed on Pid since a registered term can be anything. Want the entry +%% keyed on Pid so that lookup is fast. +-define(MONITOR(Pid, MRef), {Pid, monitor, MRef}). + +%% Table entry containing the Term -> Pid mapping. +-define(MAPPING(Term, Pid), {Term, Pid}). + +-record(state, {id = now()}). + +%%% ---------------------------------------------------------- +%%% # add(T) +%%% +%%% Input: Term = term() +%%% +%%% Output: true +%%% +%%% Description: Associate the specified term with self(). The list of pids +%%% having this or other assocations can be retrieved using +%%% match/1. +%%% +%%% An association is removed when the calling process dies +%%% or as a result of calling del/1. Adding the same term +%%% more than once is equivalent to adding it exactly once. +%%% +%%% Note that since match/1 takes a pattern as argument, +%%% specifying a term that contains match variables is +%%% probably not a good idea +%%% ---------------------------------------------------------- + +-spec add(any()) + -> true. + +add(T) -> + call({add, fun ets:insert/2, T, self()}). + +%%% ---------------------------------------------------------- +%%% # add_new(T) +%%% +%%% Input: T = term() +%%% +%%% Output: true | false +%%% +%%% Description: Like add/1 but only one process is allowed to have the +%%% the association, false being returned if an association +%%% already exists. +%%% ---------------------------------------------------------- + +-spec add_new(any()) + -> boolean(). + +add_new(T) -> + call({add, fun insert_new/2, T, self()}). + +%%% ---------------------------------------------------------- +%%% # repl(T, NewT) +%%% +%%% Input: T, NewT = term() +%%% +%%% Output: true | false +%%% +%%% Description: Like add/1 but only replace an existing association on T, +%%% false being returned if it doesn't exist. +%%% ---------------------------------------------------------- + +-spec repl(any(), any()) + -> boolean(). + +repl(T, U) -> + call({repl, T, U, self()}). + +%%% ---------------------------------------------------------- +%%% # del(Term) +%%% +%%% Input: Term = term() +%%% +%%% Output: true +%%% +%%% Description: Remove any existing association of Term with self(). +%%% ---------------------------------------------------------- + +-spec del(any()) + -> true. + +del(T) -> + call({del, T, self()}). + +%%% ---------------------------------------------------------- +%%% # match(Pat) +%%% +%%% Input: Pat = pattern in the sense of ets:match_object/2. +%%% +%%% Output: list of {Term, Pid} +%%% +%%% Description: Return the list of associations whose Term, as specified +%%% to add/1 or add_new/1, matches the specified pattern. +%%% +%%% Note that there's no guarantee that the returned processes +%%% are still alive. (Although one that isn't will soon have +%%% its associations removed.) +%%% ---------------------------------------------------------- + +-spec match(tuple()) + -> [{term(), pid()}]. + +match(Pat) -> + ets:match_object(?TABLE, ?MAPPING(Pat, '_')). + +%% --------------------------------------------------------- +%% EXPORTED INTERNAL FUNCTIONS +%% --------------------------------------------------------- + +start_link() -> + ServerName = {local, ?SERVER}, + Options = [{spawn_opt, diameter_lib:spawn_opts(server, [])}], + gen_server:start_link(ServerName, ?MODULE, [], Options). + +state() -> + call(state). + +uptime() -> + call(uptime). + +%% pids/0 +%% +%% Output: list of {Pid, [Term, ...]} + +pids() -> + to_list(fun swap/1). + +to_list(Fun) -> + ets:foldl(fun(T,A) -> acc(Fun, T, A) end, orddict:new(), ?TABLE). + +acc(Fun, ?MAPPING(Term, Pid), Dict) -> + append(Fun({Term, Pid}), Dict); +acc(_, _, Dict) -> + Dict. + +append({K,V}, Dict) -> + orddict:append(K, V, Dict). + +id(T) -> T. + +%% terms/0 +%% +%% Output: list of {Term, [Pid, ...]} + +terms() -> + to_list(fun id/1). + +swap({X,Y}) -> {Y,X}. + +%%% ---------------------------------------------------------- +%%% # init(Role) +%%% +%%% Output: {ok, State} +%%% ---------------------------------------------------------- + +init(_) -> + ets:new(?TABLE, [bag, named_table]), + {ok, #state{}}. + +%%% ---------------------------------------------------------- +%%% # handle_call(Request, From, State) +%%% ---------------------------------------------------------- + +handle_call({add, Fun, Key, Pid}, _, State) -> + B = Fun(?TABLE, {Key, Pid}), + monitor(B andalso no_monitor(Pid), Pid), + {reply, B, State}; + +handle_call({del, Key, Pid}, _, State) -> + {reply, ets:delete_object(?TABLE, ?MAPPING(Key, Pid)), State}; + +handle_call({repl, T, U, Pid}, _, State) -> + MatchSpec = [{?MAPPING('$1', Pid), + [{'=:=', '$1', {const, T}}], + ['$_']}], + {reply, repl(ets:select(?TABLE, MatchSpec), U, Pid), State}; + +handle_call(state, _, State) -> + {reply, State, State}; + +handle_call(uptime, _, #state{id = Time} = State) -> + {reply, diameter_lib:now_diff(Time), State}; + +handle_call(_Req, _From, State) -> + {reply, nok, State}. + +%%% ---------------------------------------------------------- +%%% # handle_cast(Request, State) +%%% ---------------------------------------------------------- + +handle_cast(Msg, State)-> + warning_msg("received unexpected message:~n~w", [Msg]), + {noreply, State}. + +%%% ---------------------------------------------------------- +%%% # handle_info(Request, State) +%%% ---------------------------------------------------------- + +handle_info({'DOWN', MRef, process, Pid, _}, State) -> + ets:delete_object(?TABLE, ?MONITOR(Pid, MRef)), + ets:match_delete(?TABLE, ?MAPPING('_', Pid)), + {noreply, State}; + +handle_info(Info, State) -> + warning_msg("received unknown info:~n~w", [Info]), + {noreply, State}. + +%%% ---------------------------------------------------------- +%%% # terminate(Reason, State) +%%% ---------------------------------------------------------- + +terminate(_Reason, _State)-> + ok. + +%%% ---------------------------------------------------------- +%%% # code_change(OldVsn, State, Extra) +%%% ---------------------------------------------------------- + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%% --------------------------------------------------------- +%% INTERNAL FUNCTIONS +%% --------------------------------------------------------- + +monitor(true, Pid) -> + ets:insert(?TABLE, ?MONITOR(Pid, erlang:monitor(process, Pid))); +monitor(false, _) -> + ok. + +%% Do we need a monitor for the specified Pid? +no_monitor(Pid) -> + [] == ets:match_object(?TABLE, ?MONITOR(Pid, '_')). + +%% insert_new/2 + +insert_new(?TABLE, {Key, _} = T) -> + flush(ets:lookup(?TABLE, Key)), + ets:insert_new(?TABLE, T). + +%% Remove any processes that are dead but for which we may not have +%% received 'DOWN' yet. This is to ensure that add_new can be used +%% to register a unique name each time a process restarts. +flush(List) -> + lists:foreach(fun({_,P} = T) -> + del(erlang:is_process_alive(P), T) + end, + List). + +del(Alive, T) -> + Alive orelse ets:delete_object(?TABLE, T). + +%% repl/3 + +repl([?MAPPING(_, Pid) = M], Key, Pid) -> + ets:delete_object(?TABLE, M), + true = ets:insert(?TABLE, ?MAPPING(Key, Pid)); +repl([], _, _) -> + false. + +%% call/1 + +call(Request) -> + gen_server:call(?SERVER, Request, infinity). + +%% warning_msg/2 + +warning_msg(F, A) -> + ?diameter_warning("~p: " ++ F, [?MODULE | A]). |