New POSIX semaphore functionality

Corinna Vinschen
Mon Oct 27 12:32:00 GMT 2003

On Mon, Oct 27, 2003 at 11:10:09PM +1100, Robert Collins wrote:
> On Mon, 2003-10-27 at 23:05, Corinna Vinschen wrote:
> > The only missing functionality from POSIX semaphore now is sem_unlink().
> > I don't how to implement it correctly.  The requirement is, if a process
> > has called sem_unlink(), further calls to sem_open() using the same name
> > will create a new semaphore.  Other processes, which have still a 
> > semaphore using the same name, but opened before the call to sem_unlink(),
> > are unaffected.  This isn't supported by Windows semaphores, AFAIK.
> It isn't. Back when I was working this code, I intended to do process
> shared foo via cygserver - allowing this to work.

IMHO it would be a pity to require cygserver for POSIX semaphores.
Except for sem_unlink(), every other functionality neatly matches
what is allowed by Windows.  Perhaps we should implement sem_unlink()
so that it just returns -1 and sets errno to ENOSYS for now.


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                      
Red Hat, Inc.

More information about the Cygwin-developers mailing list