From 223163d5b9366ed429d587a24058163e6832ea50 Mon Sep 17 00:00:00 2001
From: Feng Lee <feng@emqx.io>
Date: Fri, 1 Nov 2019 08:00:35 +0800
Subject: [PATCH] Remove the 'emqx_oom' module

---
 src/emqx_oom.erl | 97 ------------------------------------------------
 1 file changed, 97 deletions(-)
 delete mode 100644 src/emqx_oom.erl

diff --git a/src/emqx_oom.erl b/src/emqx_oom.erl
deleted file mode 100644
index efc0a4c69..000000000
--- a/src/emqx_oom.erl
+++ /dev/null
@@ -1,97 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2019 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
-%%--------------------------------------------------------------------
-%% @doc OOM (Out Of Memory) monitor for the channel process.
-%% @end
-%%--------------------------------------------------------------------
-
--module(emqx_oom).
-
--include("types.hrl").
-
--export([ init/1
-        , check/1
-        , info/1
-        ]).
-
--export_type([opts/0, oom_policy/0]).
-
--type(opts() :: #{message_queue_len => non_neg_integer(),
-                  max_heap_size => non_neg_integer()
-                 }).
-
--opaque(oom_policy() :: {oom_policy, opts()}).
-
--type(reason() :: message_queue_too_long|proc_heap_too_large).
-
--define(DISABLED, 0).
-
-%% @doc Init the OOM policy.
--spec(init(opts()) -> oom_policy()).
-init(#{message_queue_len := MaxQLen,
-       max_heap_size := MaxHeapSizeInBytes}) ->
-    MaxHeapSize = MaxHeapSizeInBytes div erlang:system_info(wordsize),
-    %% If set to zero, the limit is disabled.
-    _ = erlang:process_flag(max_heap_size, #{size => MaxHeapSize,
-                                             kill => false,
-                                             error_logger => true
-                                            }),
-    {oom_policy, #{message_queue_len => MaxQLen,
-                   max_heap_size => MaxHeapSize
-                  }}.
-
-%% @doc Check self() process status against channel process management policy,
-%% return `ok | {shutdown, Reason}' accordingly.
-%% `ok': There is nothing out of the ordinary.
-%% `shutdown': Some numbers (message queue length hit the limit),
-%%             hence shutdown for greater good (system stability).
--spec(check(oom_policy()) -> ok | {shutdown, reason()}).
-check({oom_policy, #{message_queue_len := MaxQLen,
-                     max_heap_size := MaxHeapSize}}) ->
-    Qlength = proc_info(message_queue_len),
-    HeapSize = proc_info(total_heap_size),
-    do_check([{fun() -> is_exceeded(Qlength, MaxQLen) end,
-               {shutdown, message_queue_too_long}},
-              {fun() -> is_exceeded(HeapSize, MaxHeapSize) end,
-               {shutdown, proc_heap_too_large}}]).
-
-do_check([]) -> ok;
-do_check([{Pred, Result} | Rest]) ->
-    case Pred() of
-        true -> Result;
-        false -> do_check(Rest)
-    end.
-
--spec(info(oom_policy()) -> opts()).
-info({oom_policy, Opts}) -> Opts.
-
--compile({inline,
-          [ is_exceeded/2
-          , is_enabled/1
-          , proc_info/1
-          ]}).
-
-is_exceeded(Val, Max) ->
-    is_enabled(Max) andalso Val > Max.
-
-is_enabled(Max) ->
-    is_integer(Max) andalso Max > ?DISABLED.
-
-proc_info(Key) ->
-    {Key, Value} = erlang:process_info(self(), Key),
-    Value.
-