Problem with VMS_SUPPORT.C

[COLLOT Jean-Yves]

John Malmberg wrote:
> Unfortunately this is the wrong thing to do when their are multiple 
> users accessing the file.  If one of them modifies the file on purpose, 
> that modification date gets lost.

Yes, that is true. 

> Either pure RMS or ACP calls need to be used, or an extension is needed 
> for the C RTL.  The extension would be to allow XABs to be added on to a 
> file open request.

I do not understand what you mean by this. Currently, the Samba routine that
restores the modification date after a Read/write open and no changes of the
file uses an ACP call, but it's probably not your point. In my
understanding, the problem happens when :
- Samba opens a file in read/write mode
- Somebody else (let's name him X) opens the file in read/write mode too.
Note that X is not another Samba, because the Samba locks would prevent
that.
- X modifies the file and closes it : the modif date is changed, for a good
reason,
- Samba then closes the file, with no changes done, and restores the
original modif date, and that's bad.

The best idea I have is to check, just before restoring the date, that the
modif date is still identical to the one we got at open time, but even this
is not 100% sure. You have probably a better idea, so please tell me.