From owner-freebsd-arch@FreeBSD.ORG Mon Dec 13 22:39:16 2004 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 69C8216A4CE for ; Mon, 13 Dec 2004 22:39:16 +0000 (GMT) Received: from zircon.seattle.wa.us (dsl231-043-165.sea1.dsl.speakeasy.net [216.231.43.165]) by mx1.FreeBSD.org (Postfix) with SMTP id 0BF7043D5F for ; Mon, 13 Dec 2004 22:39:16 +0000 (GMT) (envelope-from joe@zircon.seattle.wa.us) Received: (qmail 64836 invoked from network); 13 Dec 2004 22:39:51 -0000 Received: from localhost (HELO localhost.zircon.seattle.wa.us) (127.0.0.1) by localhost with SMTP; 13 Dec 2004 22:39:51 -0000 From: Joe Kelsey To: Julian Elischer In-Reply-To: <41BE15EE.5060704@elischer.org> References: <1102975803.30309.196.camel@zircon.zircon.seattle.wa.us> <41BE15EE.5060704@elischer.org> Content-Type: text/plain Date: Mon, 13 Dec 2004 14:39:51 -0800 Message-Id: <1102977591.30309.203.camel@zircon.zircon.seattle.wa.us> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit cc: arch@freebsd.org Subject: Re: Fixing Posix semaphores X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Dec 2004 22:39:16 -0000 On Mon, 2004-12-13 at 14:21 -0800, Julian Elischer wrote: > > Joe Kelsey wrote: > > >I have a desire to fix posix semaphores in at least 5.3. The current > >implementation doesn't actually follow the "spirit" of the standard, > >even though it technically qualifies in a somewhat degraded sense. I > >refer to the fact that the current implementation treats posix > >semaphores as completely contained inside the kernel and essentially > >divorced from the filesystem. The true "spirit" of the standard places > >the semaphores directly in the file system, similar to named pipes. > >However the current implementation treats the supplied "name" as a > >14-character identifier, required to begin with a slash and contain no > >other slashes. Pretty weak. > > > >Well, in order to fix this, we need to add file system code and come up > >with a new type. I currently have some time to spend on something like > >this and am willing to put in whatever effort it takes. Does anyone > >want to add their own ideas or requirements? > > > >I currently run 5.3, but I suppose I could think about running current > >at some point in the future. > > > > I don't think that the spirit is to do what you suggest. > I have always interpretted it to be a separate namespace. > does the posix "mknod" definition mention how to make a semaphore? POSIX does not define or allow use of mknod to create a named semaphore. Only sem_open() can create a named semaphore. The "spirit", as implemented in other OS', clearly indicates the use of file system names, not the restricted 14-character name used by FreeBSD. For instance, Solaris uses file system names. /Joe