[erlang-questions] net_kernel garbage collection

[Michael Truog]

I don't think so.  You should be able to determine where the problem
lies with the instrument module here:
http://erlang.org/doc/man/instrument.html

You just need to feed the options "+Mim true +Mis true" to the VM before
you use it (in documentation).

Erickson, John wrote:
> I was under the impression the garbage collection was per-process.  If so, will the process death of some unrelated process somehow affect the net_kernel (erlang system) process?
>
> John
>
> -----Original Message-----
> From: Michael Truog [mailto:mjtruog@REDACTED] 
> Sent: Wednesday, September 23, 2009 3:56 PM
> To: Erickson, John
> Cc: erlang-questions@REDACTED
> Subject: Re: [erlang-questions] net_kernel garbage collection
>
> You need to spawn a short-lived process since the process death will
> trigger garbage collection.  If you want to be forceful about it, you
> can do something like the code I have attached below.
>
> Erickson, John wrote:
>   
>> Hello, I have a program that often has several gb of garbage under a process which was started from net_kernel:spawn_func and usually runs erlang:bif_return_trap.  If I manually run garbage collection on this process, it will free this memory, but I was wondering if there is anyway to reduce the amount of garbage that is generated or periodically run garbage collection automatically.
>>
>> John
>>   
>>     
> %%% -*- coding: utf-8; Mode: erlang; tab-width: 4; c-basic-offset: 4;
> indent-tabs-mode: nil -*-
> %%% ex: set softtabstop=4 tabstop=4 shiftwidth=4 expandtab
> fileencoding=utf-8:
> %%%
> %%%------------------------------------------------------------------------
> %%% @doc
> %%% Enforce immediate garbage collection on a function
> %%% @end
> %%%
> %%% BSD LICENSE
> %%%
> %%% Copyright (c) 2009, Michael Truog <mjtruog at gmail dot com>
> %%% All rights reserved.
> %%%
> %%% Redistribution and use in source and binary forms, with or without
> %%% modification, are permitted provided that the following conditions
> are met:
> %%%
> %%%     * Redistributions of source code must retain the above copyright
> %%%       notice, this list of conditions and the following disclaimer.
> %%%     * Redistributions in binary form must reproduce the above copyright
> %%%       notice, this list of conditions and the following disclaimer in
> %%%       the documentation and/or other materials provided with the
> %%%       distribution.
> %%%     * All advertising materials mentioning features or use of this
> %%%       software must display the following acknowledgment:
> %%%         This product includes software developed by Michael Truog
> %%%     * The name of the author may not be used to endorse or promote
> %%%       products derived from this software without specific prior
> %%%       written permission
> %%%
> %%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
> %%% CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
> %%% INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
> %%% OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> %%% DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
> %%% CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> %%% SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
> %%% BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
> %%% SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> %%% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
> %%% WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
> %%% NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
> %%% OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
> %%% DAMAGE.
> %%%
> %%% @author Michael Truog <mjtruog [at] gmail (dot) com>
> %%% @copyright 2009 Michael Truog
> %%% @version 0.0.1
> %%%------------------------------------------------------------------------
>
> -module(immediate_gc).
> -author('mjtruog [at] gmail (dot) com').
>
> %% external interface
> -export([sync_fun/2, sync_fun/3,
>          async_fun/2, async_fun/3]).
>
> %%%------------------------------------------------------------------------
> %%% External interface functions
> %%%------------------------------------------------------------------------
>
> %%-------------------------------------------------------------------------
> %% @doc
> %% Make a synchronous call to a function that will be
> %% garbage collected when the function returns.
> %% @end
> %%-------------------------------------------------------------------------
>
> -spec sync_fun(M :: atom(), F :: atom(), A :: list()) -> any().
>
> sync_fun(M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
>     Parent = self(),
>     Child = erlang:spawn_opt(fun() ->
>         Parent ! {self(), erlang:apply(M, F, A)},
>         erlang:garbage_collect()
>     end, [link, {fullsweep_after, 0}]),
>     receive
>         {Child, Result} -> Result
>     end.
>
> %%-------------------------------------------------------------------------
> %% @doc
> %% Make a synchronous call to an anonymous function that will be
> %% garbage collected when the function returns.
> %% @end
> %%-------------------------------------------------------------------------
>
> -spec sync_fun(F :: fun(), A :: list()) -> any().
>
> sync_fun(F, A) when is_function(F), is_list(A) ->
>     Parent = self(),
>     Child = erlang:spawn_opt(fun() ->
>         Parent ! {self(), erlang:apply(F, A)},
>         erlang:garbage_collect()
>     end, [link, {fullsweep_after, 0}]),
>     receive
>         {Child, Result} -> Result
>     end.
>
> %%-------------------------------------------------------------------------
> %% @doc
> %% Make a asynchronous call to a function that will be
> %% garbage collected when the function returns.
> %% @end
> %%-------------------------------------------------------------------------
>
> -spec async_fun(M :: atom(), F :: atom(), A :: list()) -> pid().
>
> async_fun(M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
>     erlang:spawn_opt(fun() ->
>         erlang:apply(M, F, A),
>         erlang:garbage_collect()
>     end, [link, {fullsweep_after, 0}]).
>
> %%-------------------------------------------------------------------------
> %% @doc
> %% Make a asynchronous call to an anonymous function that will be
> %% garbage collected when the function returns.
> %% @end
> %%-------------------------------------------------------------------------
>
> -spec async_fun(F :: fun(), A :: list()) -> pid().
>
> async_fun(F, A) when is_function(F), is_list(A) ->
>     erlang:spawn_opt(fun() ->
>         erlang:apply(F, A),
>         erlang:garbage_collect()
>     end, [link, {fullsweep_after, 0}]).
>
>
>
>