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Diffstat (limited to 'src/rabbit_memsup.erl')
| -rw-r--r-- | src/rabbit_memsup.erl | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/rabbit_memsup.erl b/src/rabbit_memsup.erl new file mode 100644 index 00000000..b0d57cb2 --- /dev/null +++ b/src/rabbit_memsup.erl @@ -0,0 +1,142 @@ +%% 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 Developers of the Original Code are LShift Ltd, +%% Cohesive Financial Technologies LLC, and Rabbit Technologies Ltd. +%% +%% Portions created before 22-Nov-2008 00:00:00 GMT by LShift Ltd, +%% Cohesive Financial Technologies LLC, or Rabbit Technologies Ltd +%% are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial +%% Technologies LLC, and Rabbit Technologies Ltd. +%% +%% Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift +%% Ltd. Portions created by Cohesive Financial Technologies LLC are +%% Copyright (C) 2007-2009 Cohesive Financial Technologies +%% LLC. Portions created by Rabbit Technologies Ltd are Copyright +%% (C) 2007-2009 Rabbit Technologies Ltd. +%% +%% All Rights Reserved. +%% +%% Contributor(s): ______________________________________. +%% + +-module(rabbit_memsup). + +-behaviour(gen_server). + +-export([start_link/1]). + +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + terminate/2, code_change/3]). + +-export([update/0]). + +-record(state, {memory_fraction, + timeout, + timer, + mod, + mod_state, + alarmed + }). + +-define(SERVER, memsup). %% must be the same as the standard memsup + +-define(DEFAULT_MEMORY_CHECK_INTERVAL, 1000). + +%%---------------------------------------------------------------------------- + +-ifdef(use_specs). + +-spec(start_link/1 :: (atom()) -> {'ok', pid()} | 'ignore' | {'error', any()}). +-spec(update/0 :: () -> 'ok'). + +-endif. + +%%---------------------------------------------------------------------------- + +start_link(Args) -> + gen_server:start_link({local, ?SERVER}, ?MODULE, [Args], []). + +update() -> + gen_server:cast(?SERVER, update). + +%%---------------------------------------------------------------------------- + +init([Mod]) -> + Fraction = os_mon:get_env(memsup, system_memory_high_watermark), + TRef = start_timer(?DEFAULT_MEMORY_CHECK_INTERVAL), + InitState = Mod:init(), + State = #state { memory_fraction = Fraction, + timeout = ?DEFAULT_MEMORY_CHECK_INTERVAL, + timer = TRef, + mod = Mod, + mod_state = InitState, + alarmed = false }, + {ok, internal_update(State)}. + +start_timer(Timeout) -> + {ok, TRef} = timer:apply_interval(Timeout, ?MODULE, update, []), + TRef. + +%% Export the same API as the real memsup. Note that +%% get_sysmem_high_watermark gives an int in the range 0 - 100, while +%% set_sysmem_high_watermark takes a float in the range 0.0 - 1.0. +handle_call(get_sysmem_high_watermark, _From, State) -> + {reply, trunc(100 * State#state.memory_fraction), State}; + +handle_call({set_sysmem_high_watermark, Float}, _From, State) -> + {reply, ok, State#state{memory_fraction = Float}}; + +handle_call(get_check_interval, _From, State) -> + {reply, State#state.timeout, State}; + +handle_call({set_check_interval, Timeout}, _From, State) -> + {ok, cancel} = timer:cancel(State#state.timer), + {reply, ok, State#state{timeout = Timeout, timer = start_timer(Timeout)}}; + +handle_call(get_memory_data, _From, + State = #state { mod = Mod, mod_state = ModState }) -> + {reply, Mod:get_memory_data(ModState), State}; + +handle_call(_Request, _From, State) -> + {noreply, State}. + +handle_cast(update, State) -> + {noreply, internal_update(State)}; + +handle_cast(_Request, State) -> + {noreply, State}. + +handle_info(_Info, State) -> + {noreply, State}. + +terminate(_Reason, _State) -> + ok. + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +internal_update(State = #state { memory_fraction = MemoryFraction, + alarmed = Alarmed, + mod = Mod, mod_state = ModState }) -> + ModState1 = Mod:update(ModState), + {MemTotal, MemUsed, _BigProc} = Mod:get_memory_data(ModState1), + NewAlarmed = MemUsed / MemTotal > MemoryFraction, + case {Alarmed, NewAlarmed} of + {false, true} -> + alarm_handler:set_alarm({system_memory_high_watermark, []}); + {true, false} -> + alarm_handler:clear_alarm(system_memory_high_watermark); + _ -> + ok + end, + State #state { mod_state = ModState1, alarmed = NewAlarmed }. |