system wide mutex

[Skip Montanaro]

On Sun, Feb 9, 2014 at 8:45 AM, Roy Smith <roy at panix.com> wrote:
> This is true of all mutexes, no?

Hmmm... You might well be right. I thought that use of the O_EXLOCK
flag in the open(2) system call would prevent other processes from
opening the file, but (at least on my Mac) it just blocks until the
first process closes the file. Perhaps there are some other flags you
can use to cause the second open(2) call to error out.

Skip