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Diffstat (limited to 'src/pmon.erl')
-rw-r--r-- | src/pmon.erl | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/pmon.erl b/src/pmon.erl new file mode 100644 index 00000000..45786577 --- /dev/null +++ b/src/pmon.erl @@ -0,0 +1,64 @@ +%% The contents of this file are subject to the Mozilla Public License +%% Version 1.1 (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.mozilla.org/MPL/ +%% +%% 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. +%% +%% The Original Code is RabbitMQ. +%% +%% The Initial Developer of the Original Code is VMware, Inc. +%% Copyright (c) 2011-2012 VMware, Inc. All rights reserved. +%% + +-module(pmon). + +-export([new/0, monitor/2, monitor_all/2, demonitor/2, is_monitored/2, erase/2, + monitored/1, is_empty/1]). + +-ifdef(use_specs). + +%%---------------------------------------------------------------------------- + +-export_type([?MODULE/0]). + +-opaque(?MODULE() :: dict()). + +-spec(new/0 :: () -> ?MODULE()). +-spec(monitor/2 :: (pid(), ?MODULE()) -> ?MODULE()). +-spec(monitor_all/2 :: ([pid()], ?MODULE()) -> ?MODULE()). +-spec(demonitor/2 :: (pid(), ?MODULE()) -> ?MODULE()). +-spec(is_monitored/2 :: (pid(), ?MODULE()) -> boolean()). +-spec(erase/2 :: (pid(), ?MODULE()) -> ?MODULE()). +-spec(monitored/1 :: (?MODULE()) -> [pid()]). +-spec(is_empty/1 :: (?MODULE()) -> boolean()). + +-endif. + +new() -> dict:new(). + +monitor(Pid, M) -> + case dict:is_key(Pid, M) of + true -> M; + false -> dict:store(Pid, erlang:monitor(process, Pid), M) + end. + +monitor_all(Pids, M) -> lists:foldl(fun monitor/2, M, Pids). + +demonitor(Pid, M) -> + case dict:find(Pid, M) of + {ok, MRef} -> erlang:demonitor(MRef), + dict:erase(Pid, M); + error -> M + end. + +is_monitored(Pid, M) -> dict:is_key(Pid, M). + +erase(Pid, M) -> dict:erase(Pid, M). + +monitored(M) -> dict:fetch_keys(M). + +is_empty(M) -> dict:size(M) == 0. |