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Article #2839Re: more on locks
From: Henry J. Cobb
Date: Fri, 24 Sep 1993 12:18
Date: Fri, 24 Sep 1993 12:18
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1589 bytes
Thanks, OK I won't mess with the policy of global database locking. But unless there is something else I've overlooked, I'll add a section to filopen() (protected by a #ifndef NO_ATOMIC_CREATION (I hope that nothing is really that broken)). I'll check for spec == "atomic" and do an open() with O_WRONLY | O_CREAT | O_EXCL followed by an fdopen() for lockfile itself. Then I'll change the ...WriteLock functions to atomically create the lockfile, or remove it, etc. Also I'd like to set a special protocol in the client/server setup to request a break of the lock. All of the OS'es I am aware of have some procedure for atomic file creation, and I know of no other IPC which is common to all of them. If this is a problem under say VMS or MVS or Novell or Appleshare, etc., please let me know. -- Henry J. Cobb hcobb@fly2.berkeley.edu SFB Tyrant
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f6d40,55885d0bd44c2676 X-Google-Attributes: gidf6d40,public X-Google-ArrivalTime: 1993-09-24 12:59:47 PST Path: arc1-ca.pugleaf.net!gmd.de!xlink.net!sol.ctr.columbia.edu!howland.reston.ans.net!agate!fly2.berkeley.edu!hcobb From: hcobb@fly2.berkeley.edu (Henry J. Cobb) Newsgroups: bionet.software.acedb Subject: Re: more on locks Date: 24 Sep 93 12:18:39 Organization: University of California, Berkeley Lines: 22 Distribution: bionet Message-ID: <HCOBB.93Sep24121839@fly2.berkeley.edu> References: <1993Sep23.214236.3664@gserv1.dl.ac.uk> NNTP-Posting-Host: fly2.berkeley.edu In-reply-to: rd@uk.ac.cam.mrc-lmb's message of Thu, 23 Sep 1993 21:35:09 GMT