Subject: Re: POSIX semaphores - threads only?
To: Matthew Mondor <>
From: Andrew Doran <>
List: tech-kern
Date: 12/06/2007 16:16:47
On Thu, Dec 06, 2007 at 03:58:06PM +0000, Andrew Doran wrote:

> On Thu, Dec 06, 2007 at 10:50:44AM -0500, Matthew Mondor wrote:
> > I read in sem_init(3) man page that the implementation did not allow
> > interprocess synchronization using POSIX semaphores (or at least
> > that's what I understand from it).
> > 
> > Is this correct?
> No, the manual page is out of date. I'll see about updating it.

I was wrong. Anonymous semaphores will only be shared if the process forks,
but does not exec. If you mmap() a region and it has a semaphore then you
are out of luck.