Re: Rename atomicity

[Assar Westerlund]

Mike Castle <address@hidden> writes:
> On Sun, Mar 04, 2001 at 06:32:25AM +0100, Jim Meyering wrote:
> > Do you know of a system on which such a use of rename is _not_ atomic?
> 
> NT.  (NT will happily rename() across disks, hardly an atomic operation).

What rename() is that?  It's not the one in their posix library I
assume?  Is there a rename function in any of the ordinary set of libraries.

> Some earlier implementations of Linux.

Any version that is still in use?

> I believe some implementations of Solaris (for performance reasons, rename
> was not made atomic).

Could you give pointers to the information on which renames() aren't
atomic on what versions of Linux and Solaris?

I think testing for this at configure time is rather error-prone and
something that's best not done.  So, I have to wonder why is this
information needed and where is it used.  If you're writing code that
depends on this and that has to be able to run on systems where you
cannot guarantee that rename isn't atomic, atomicity has to be
accomplished in some other way.

Derek: what did you want this for?  CVS?  And have you escaped on
vacation yet? :-)

/assar