From owner-freebsd-hackers Wed Aug 25 16:39:47 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (Postfix) with ESMTP id 0133414C49 for ; Wed, 25 Aug 1999 16:39:41 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id JAA04258; Thu, 26 Aug 1999 09:09:37 +0930 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.3/8.9.0) id JAA06222; Thu, 26 Aug 1999 09:09:33 +0930 (CST) Date: Thu, 26 Aug 1999 09:09:33 +0930 From: Greg Lehey To: Thomas David Rivers Cc: bee@wipinfo.soft.net, hackers@FreeBSD.ORG Subject: Re: Mandatory locking? Message-ID: <19990826090933.T83273@freebie.lemis.com> References: <000301beeea6$1ea898a0$88291fac@wipro.tcpn.com> <199908251005.GAA95394@lakes.dignus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: <199908251005.GAA95394@lakes.dignus.com>; from Thomas David Rivers on Wed, Aug 25, 1999 at 06:05:11AM -0400 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wednesday, 25 August 1999 at 6:05:11 -0400, Thomas David Rivers wrote: >> All the files under Tandem's NSK has mandatory locking. The file cannot be >> opened if another process has it opened. some thing like >> >> * if the file is opened for reading, any one can open it for >> reading but opening for writing gives error >> * if the file is open for writing, it can't be opened for >> read/write >> * if the process holding the file is killed, the lock is gone >> * it is possible to get the pid of the process(es) which has >> a given file open (like which process has file "xyz" open? >> kind of query). btw, is there any way to get this info now in FBSD? > > This sounds interesting... > > But - aren't there NFS issues? I mean, in stateless access to > a file - how do you know if the process holding the file is killed > if it's remote? NSK is a prorietary operating system ("NonStop Kernel", previously known as Guardian, previously known as TOS), not UNIX. There is no NFS, and there is no distinction between network access and local access: all goes over the message system. When a file is closed, its locks are released. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message