From owner-svn-src-all@FreeBSD.ORG Wed Dec 9 13:54:33 2009 Return-Path: Delivered-To: svn-src-all@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E37771065670; Wed, 9 Dec 2009 13:54:33 +0000 (UTC) (envelope-from gallatin@cs.duke.edu) Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by mx1.freebsd.org (Postfix) with ESMTP id A607F8FC0A; Wed, 9 Dec 2009 13:54:33 +0000 (UTC) Received: from [172.31.193.10] (cpe-174-097-131-132.nc.res.rr.com [174.97.131.132]) (authenticated bits=0) by duke.cs.duke.edu (8.14.2/8.14.2) with ESMTP id nB9DsWia007162 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 9 Dec 2009 08:54:32 -0500 (EST) Message-ID: <4B1FAC12.6080907@cs.duke.edu> Date: Wed, 09 Dec 2009 08:54:26 -0500 From: Andrew Gallatin User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: John Baldwin References: <200912082048.nB8Km6aP099420@svn.freebsd.org> <200912081645.37356.jhb@freebsd.org> <20091208221028.GA57735@stack.nl> <200912081742.58162.jhb@freebsd.org> In-Reply-To: <200912081742.58162.jhb@freebsd.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org, Jilles Tjoelker Subject: Re: svn commit: r200274 - head/lib/libc/gen X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Dec 2009 13:54:34 -0000 John Baldwin wrote: > The fact that we don't fail attempts to use pshared outright is probably > dubious. They cannot possibly work as currently implemented aside from fork() > since the structure embeds a file descriptor and file descriptor indices are a > per-process namespace, not a global namespace. FWIW, this is what confused me. It tends to be kind of a land-mine, since programs can be ported from Linux, and appear to work at first for casual use. If we don't support pshared, we should return an error from sem_init() to make it obvious. Also, perhaps the sem_init() man page should mention sem_open(), since that seems to be the only way to really share a semaphore between processes on FreeBSD. Drew