[cmake-developers] New command 'file(LOCK_DIRECTORY ...)'

[Brad King]

On 10/05/2014 04:59 PM, Ruslan Baratov via cmake-developers wrote:
> So it can't be resolved without some low-level management. I'm thinking 
> about `file` command sub-option like LOCK_DIRECTORY: 
> `file(LOCK_DIRECTORY "/path/to/shared-dir")`. Does it sounds doable?

I think it is a reasonable proposal.  However, more design is needed
here, including at least the following items:

* There needs to be a way to define the scope of the lock other than
  "until cmake exits".  For example, "until current function exits".

* There needs to be a way to explicitly unlock early, or to explicitly
  release management of the lock (e.g. to pass to some other process).

* The implementation on Windows needs to be handled carefully.
  The "safe" way to delete a file there is to open it with a handle
  that is marked as delete-on-close, and then close the handle.
  That way the file is eventually deleted even if other processes
  currently have it open/locked.  I don't know if there is an
  equivalent for a directory.

Thanks,
-Brad