[racket-dev] the preferences file under Windows

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Thu Jan 13 17:36:49 EST 2011

At Thu, 13 Jan 2011 17:29:15 -0500, Eli Barzilay wrote:
> 30 minutes ago, Matthew Flatt wrote:
> > 
> > Unfortunately (again), the lock file has to exist alongside the data
> > file, and our existing preferences files are not accompanied by lock
> > files. It's no good assuming that you don't need the lock if there's
> > no lock file present, because the lock file might get created in
> > between the time that you try to use the lock file and the time that
> > you try to open the preferences file.
> Why not always use such a lock file, creating it if it's not there --
> and then you can open it once per process, and lock/unlock it for each
> read/write of the actual file.  Does this fail somehow?

That's a good idea. It's a little bit of option 1, in that a reader
will sometimes need to write a file --- but only in the transitional
case of dealing with an existing preference file without a lock file.

Posted on the dev mailing list.