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authorAnders Svensson <[email protected]>2011-10-21 10:43:17 +0200
committerAnders Svensson <[email protected]>2011-10-21 10:43:17 +0200
commit5dc64cffb084e8abc6e5908025833481331f38de (patch)
tree43e8643b235791b81ade3caf9f3671d206a44527 /lib/diameter/src/base/diameter_reg.erl
parent1cc659425002846f4f553add9d027ca620b42a22 (diff)
parent6c048c57a4714e033f484ff79425ce847e9a43e9 (diff)
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Merge branch 'anders/diameter/make/OTP-9638'
* anders/diameter/make/OTP-9638: Dumb down release target to Solaris /usr/ucb/install Dumb down opt/release targets to make 3.80 Minor tweaks and cleanup Need absolute -pa for bootstrap build Simpler release targets for src subdirectories Use secondary expansion for src subdirectory rules One makefile for src build instead of recursion Remove app dependency on compiler to avoid forced recompilation Move diameter_exprecs to compiler directory
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+%%
+%% %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) ->
+ ?UNEXPECTED([Req, From]),
+ {reply, nok, State}.
+
+%%% ----------------------------------------------------------
+%%% # handle_cast(Request, State)
+%%% ----------------------------------------------------------
+
+handle_cast(Msg, State)->
+ ?UNEXPECTED([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) ->
+ ?UNEXPECTED([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).