Re: Locking *STMFs in the IFS

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

> Can anybody advise me on how to, from an OS/400-native application, get an
> exclusive lock on a stream file?

open() API with the O_SHARE_NONE flag will give you an "exclusive" lock on
the file itself (as opposed to a lock on a range of bytes within the file)


> For a while, I was looking at the locking functions of the "fcntl()"
> UNIX-type API, but then I noticed that they (1) only produce advisory,
> rather than mandatory, locks, and (2) don't persist while the file isn't
> open.

The DosSetFileLocks() API should, in theory, give you a manditory lock on
a stream file.  I haven't tried it myself.

As far as I know there is no way to set a lock that will persist after the
file is closed.  I suppose you could move the stream file to a temporary
directory while you want it to be "in use" and move it back when you're
done...

But there's nothing that's exactly equivalent to ALCOBJ as far as I know.