Date: Thu, 26 Aug 1999 09:09:33 +0930 From: Greg Lehey <grog@lemis.com> To: Thomas David Rivers <rivers@dignus.com> Cc: bee@wipinfo.soft.net, hackers@FreeBSD.ORG Subject: Re: Mandatory locking? Message-ID: <19990826090933.T83273@freebie.lemis.com> In-Reply-To: <199908251005.GAA95394@lakes.dignus.com>; from Thomas David Rivers on Wed, Aug 25, 1999 at 06:05:11AM -0400 References: <000301beeea6$1ea898a0$88291fac@wipro.tcpn.com> <199908251005.GAA95394@lakes.dignus.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19990826090933.T83273>