more on locks
Bradley K. Sherman
bks at s27w007.pswfs.gov
Sat Sep 25 11:57:08 EST 1993
In article <HCOBB.93Sep24121839 at fly2.berkeley.edu> hcobb at fly2.berkeley.edu (Henry J. Cobb) writes:
> I'll check for spec == "atomic" and do an open() with O_WRONLY |
>O_CREAT | O_EXCL followed by an fdopen() for lockfile itself.
> 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.
There was a nasty problem with NFS and SunOS 3.x where calls such
as this (open (...O_CREAT...)) appeared to succeed but which did
not preempt similar calls from other workstations. This was
caused by local file caching. I do not know if this feature of
Sun/NFS interaction has been fixed in subsequent releases, or
whether it plagues other NFS implementations.
Bradley K. Sherman P.O. Box 245
Computer Scientist Berkeley, CA, 94701
Dendrome Project 510-559-6437 FAX: 510-559-6440
Institute of Forest Genetics Internet: bks at s27w007.pswfs.gov
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