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From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: Re: getenv_r
Date: Thu, 5 Mar 2015 01:41:33 +0100	[thread overview]
Message-ID: <20150305004133.GI16260@port70.net> (raw)
In-Reply-To: <20150304230920.GA21838@wilbur.25thandClement.com>

* William Ahern <william@25thandClement.com> [2015-03-04 15:09:20 -0800]:
> I noticed that getenv is not thread-safe. Would there be any interest in
> accepting a patch to implement getenv_r (a NetBSD function) and internal
> locking? Other than leaving getenv, setenv, and putenv unsafe in threaded
> environments, the only other alternative is the ugliness that glibc,
> Solaris, and some others implement, which is basically to leak environ
> memory.

getenv is thread-safe if the environ is not modified

in a multi-threaded application environ modification
is unsafe and problematic even if you do the locks:
different threads may want different value for an env
var and when you read an env var you cannot know if
it is up to date when you want to use it.

does netbsd use getenv_r somewhere to solve some issue?


  reply	other threads:[~2015-03-05  0:41 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-04 23:09 getenv_r William Ahern
2015-03-05  0:41 ` Szabolcs Nagy [this message]
2015-03-05  1:34   ` getenv_r William Ahern
2015-03-05  2:44     ` getenv_r Rich Felker
2015-03-05  8:59     ` getenv_r Szabolcs Nagy

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