Rainbows! Rack HTTP server user/dev discussion
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From: Eric Wong <normalperson-rMlxZR9MS24@public.gmane.org>
To: Alexandre Riveira
	<alexandre-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org>
Cc: rainbows-talk@rubyforge.org
Subject: Re: background threads
Date: Mon, 18 Jun 2012 22:53:24 +0000	[thread overview]
Message-ID: <20120618225324.GD3151@dcvr.yhbt.net> (raw)
In-Reply-To: <4FDF85C2.1030900-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org>

Alexandre Riveira <alexandre-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org> wrote:
> Em 18-06-2012 22:42, Eric Wong escreveu:
> >If you only want one background thread for all workers, it
> >probably is best to just use a separate daemon independent of the
> >Rainbows! server.
> I want only one worker to run a background thread. I would like to
> ensure that only one worker thread will be in the background. Sure
> ... using rainbows :)

It's a bad idea, I think...

You can use process-shared locks Ruby provides File#flock.
It's also possible to get fcntl()-based locking to work with pack().

Maybe there's extensions to share locks with multiple processes
(e.g. POSIX semaphores, database-based locks in Redis/MySQL/Postgres).

...Or even use a really ugly method of using TCPServer to bind to a
pre-determined port (and bailing on Errno::EADDRINUSE) (no need to
accept connections on the TCPServer, just keep the object around
so it doesn't get close(2)-ed on GC.

But really, I think this type of background thread is a bad idea
for Rainbows! (or any HTTP server).
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      parent reply	other threads:[~2012-06-18 22:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-18 18:32 background threads Alexandre Riveira
     [not found] ` <4FDF7420.7030300-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org>
2012-06-18 21:55   ` Eric Wong
     [not found]     ` <20120618215550.GA31162-yBiyF41qdooeIZ0/mPfg9Q@public.gmane.org>
2012-06-18 19:08       ` Alexandre Riveira
     [not found]         ` <4FDF7CA0.6030103-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org>
2012-06-18 22:21           ` Eric Wong
2012-06-18 19:26       ` Alexandre Riveira
     [not found]     ` <4FDF81A5.6080605@objectdata.com.br>
     [not found]       ` <4FDF81A5.6080605-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org>
2012-06-18 22:42         ` Eric Wong
     [not found]           ` <4FDF85C2.1030900@objectdata.com.br>
     [not found]             ` <4FDF85C2.1030900-VwDbj2YsoUp0ZRtCdD4y8VAUjnlXr6A1@public.gmane.org>
2012-06-18 22:53               ` Eric Wong [this message]

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