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Diffstat (limited to 'lib/diameter/src/base/diameter_stats.erl')
-rw-r--r-- | lib/diameter/src/base/diameter_stats.erl | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/lib/diameter/src/base/diameter_stats.erl b/lib/diameter/src/base/diameter_stats.erl new file mode 100644 index 0000000000..71479afa95 --- /dev/null +++ b/lib/diameter/src/base/diameter_stats.erl @@ -0,0 +1,342 @@ +%% +%% %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% +%% + +%% +%% Statistics collector. +%% + +-module(diameter_stats). +-compile({no_auto_import, [monitor/2]}). + +-behaviour(gen_server). + +-export([reg/1, reg/2, + incr/1, incr/2, incr/3, + read/1, + flush/0, flush/1]). + +%% supervisor callback +-export([start_link/0]). + +%% gen_server callbacks +-export([init/1, + terminate/2, + handle_call/3, + handle_cast/2, + handle_info/2, + code_change/3]). + +%% debug +-export([state/0, + uptime/0]). + +-include("diameter_internal.hrl"). + +%% ets table containing stats. reg(Pid, Ref) inserts a {Pid, Ref}, +%% incr(Counter, X, N) updates the counter keyed at {Counter, X}, and +%% Pid death causes counters keyed on {Counter, Pid} to be deleted and +%% added to those keyed on {Counter, Ref}. +-define(TABLE, ?MODULE). + +%% Name of registered server. +-define(SERVER, ?MODULE). + +%% Entries in the table. +-define(REC(Key, Value), {Key, Value}). + +%% Server state. +-record(state, {id = now()}). + +-type counter() :: any(). +-type contrib() :: any(). + +%%% --------------------------------------------------------------------------- +%%% # reg(Pid, Contrib) +%%% +%%% Description: Register a process as a contributor of statistics +%%% associated with a specified term. Statistics can be +%%% contributed by specifying either Pid or Contrib as +%%% the second argument to incr/3. Statistics contributed +%%% by Pid are folded into the corresponding entry for +%%% Contrib when the process dies. +%%% +%%% Contrib can be any term but should not be a pid +%%% passed as the first argument to reg/2. Subsequent +%%% registrations for the same Pid overwrite the association +%%% --------------------------------------------------------------------------- + +-spec reg(pid(), contrib()) + -> true. + +reg(Pid, Contrib) + when is_pid(Pid) -> + call({reg, Pid, Contrib}). + +-spec reg(contrib()) + -> true. + +reg(Ref) -> + reg(self(), Ref). + +%%% --------------------------------------------------------------------------- +%%% # incr(Counter, Contrib, N) +%%% +%%% Description: Increment a counter for the specified contributor. +%%% +%%% Contrib will typically be an argument passed to reg/2 +%%% but there's nothing that requires this. In particular, +%%% if Contrib is a pid that hasn't been registered then +%%% counters are unaffected by the death of the process. +%%% --------------------------------------------------------------------------- + +-spec incr(counter(), contrib(), integer()) + -> integer(). + +incr(Ctr, Contrib, N) -> + update_counter({Ctr, Contrib}, N). + +incr(Ctr, N) + when is_integer(N) -> + incr(Ctr, self(), N); + +incr(Ctr, Contrib) -> + incr(Ctr, Contrib, 1). + +incr(Ctr) -> + incr(Ctr, self(), 1). + +%%% --------------------------------------------------------------------------- +%%% # read(Contribs) +%%% +%%% Description: Retrieve counters for the specified contributors. +%%% --------------------------------------------------------------------------- + +-spec read([contrib()]) + -> [{contrib(), [{counter(), integer()}]}]. + +read(Contribs) -> + lists:foldl(fun(?REC({T,C}, N), D) -> orddict:append(C, {T,N}, D) end, + orddict:new(), + ets:select(?TABLE, [{?REC({'_', '$1'}, '_'), + [?ORCOND([{'=:=', '$1', {const, C}} + || C <- Contribs])], + ['$_']}])). + +%%% --------------------------------------------------------------------------- +%%% # flush(Contrib) +%%% +%%% Description: Retrieve and delete statistics for the specified +%%% contributor. +%%% +%%% If Contrib is a pid registered with reg/2 then statistics +%%% for both and its associated contributor are retrieved. +%%% --------------------------------------------------------------------------- + +-spec flush(contrib()) + -> [{counter(), integer()}]. + +flush(Contrib) -> + try + call({flush, Contrib}) + catch + exit: _ -> + [] + end. + +flush() -> + flush(self()). + +%%% --------------------------------------------------------- +%%% EXPORTED INTERNAL FUNCTIONS +%%% --------------------------------------------------------- + +start_link() -> + ServerName = {local, ?SERVER}, + Module = ?MODULE, + Args = [], + Options = [{spawn_opt, diameter_lib:spawn_opts(server, [])}], + gen_server:start_link(ServerName, Module, Args, Options). + +state() -> + call(state). + +uptime() -> + call(uptime). + +%%% ---------------------------------------------------------- +%%% # init(_) +%%% +%%% Output: {ok, State} +%%% ---------------------------------------------------------- + +init([]) -> + ets:new(?TABLE, [named_table, ordered_set, public]), + {ok, #state{}}. + +%% ---------------------------------------------------------- +%% handle_call(Request, From, State) +%% ---------------------------------------------------------- + +handle_call(state, _, State) -> + {reply, State, State}; + +handle_call(uptime, _, #state{id = Time} = State) -> + {reply, diameter_lib:now_diff(Time), State}; + +handle_call({reg, Pid, Contrib}, _From, State) -> + monitor(not ets:member(?TABLE, Pid), Pid), + {reply, insert(?REC(Pid, Contrib)), State}; + +handle_call({flush, Contrib}, _From, State) -> + {reply, fetch(Contrib), State}; + +handle_call(Req, From, State) -> + ?UNEXPECTED([Req, From]), + {reply, nok, State}. + +%% ---------------------------------------------------------- +%% handle_cast(Request, State) +%% ---------------------------------------------------------- + +handle_cast({incr, Rec}, State) -> + update_counter(Rec), + {noreply, State}; + +handle_cast(Msg, State) -> + ?UNEXPECTED([Msg]), + {noreply, State}. + +%% ---------------------------------------------------------- +%% handle_info(Request, State) +%% ---------------------------------------------------------- + +handle_info({'DOWN', _MRef, process, Pid, _}, State) -> + down(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/2 + +monitor(true, Pid) -> + erlang:monitor(process, Pid); +monitor(false = No, _) -> + No. + +%% down/1 + +down(Pid) -> + L = ets:match_object(?TABLE, ?REC({'_', Pid}, '_')), + [?REC(_, Ref) = T] = lookup(Pid), + fold(Ref, L), + delete_object(T), + delete(L). + +%% Fold Pid-based entries into Ref-based ones. +fold(Ref, L) -> + lists:foreach(fun(?REC({K, _}, V)) -> update_counter({{K, Ref}, V}) end, + L). + +delete(Objs) -> + lists:foreach(fun delete_object/1, Objs). + +%% fetch/1 + +fetch(X) -> + MatchSpec = [{?REC({'_', '$1'}, '_'), + [?ORCOND([{'==', '$1', {const, T}} || T <- [X | ref(X)]])], + ['$_']}], + L = ets:select(?TABLE, MatchSpec), + delete(L), + D = lists:foldl(fun sum/2, dict:new(), L), + dict:to_list(D). + +sum({{Ctr, _}, N}, Dict) -> + dict:update(Ctr, fun(V) -> V+N end, N, Dict). + +ref(Pid) + when is_pid(Pid) -> + ets:select(?TABLE, [{?REC(Pid, '$1'), [], ['$1']}]); +ref(_) -> + []. + +%% update_counter/2 +%% +%% From an arbitrary request process. Cast to the server process to +%% insert a new element if the counter doesn't exists so that two +%% processes don't do so simultaneously. + +update_counter(Key, N) -> + try + ets:update_counter(?TABLE, Key, N) + catch + error: badarg -> + cast({incr, ?REC(Key, N)}) + end. + +%% update_counter/1 +%% +%% From the server process. + +update_counter(?REC(Key, N) = T) -> + try + ets:update_counter(?TABLE, Key, N) + catch + error: badarg -> + insert(T) + end. + +insert(T) -> + ets:insert(?TABLE, T). + +lookup(Key) -> + ets:lookup(?TABLE, Key). + +delete_object(T) -> + ets:delete_object(?TABLE, T). + +%% cast/1 + +cast(Msg) -> + gen_server:cast(?SERVER, Msg). + +%% call/1 + +call(Request) -> + gen_server:call(?SERVER, Request, infinity). |