[Info-vax] CRTL and RMS vs SSIO

[Vitaly Pustovetov]

суббота, 9 октября 2021 г. в 21:02:59 UTC+3, Dave Froble:
> On 10/9/2021 12:47 PM, Stephen Hoffman wrote: 
> 
> > C and DLM already implement range locking on OpenVMS.
> I'd really like to see the documentation and how to use it.

"File Locking
The C RTL supports byte-range file locking using the F_GETLK, F_SETLK, and F_SETLKW
commands of the fcntl function, as defined in the X/Open specification. Byte-range file locking is
supported across OpenVMS clusters. You can only use offsets that fit into 32-bit unsigned integers.
When a shared lock is set on a segment of a file, other processes on the cluster are able to set shared
locks on that segment or a portion of it. A shared lock prevents any other process from setting
an exclusive lock on any portion of the protected area. A request for a shared lock fails if the file
descriptor was not opened with read access....."(c)VSI C Run-Time Library Reference Manual