PS>
  > Is there any good way to "queue" the access?
PS>

You can set a timeout for DosSetFileLocks to wait until the locks are
granted, incidentally.  DosSetFileLocks also allows "shared" and
"exclusive" locks, which can be used to implement a "multiple readers,
single writer" solution to many problems.

  > JdeBP <
___
 X MegaMail 2.10 #0:
--- Maximus/2 3.01