On Sat, May 10, 2003 at 02:29:54AM -0400, Chris Friesen wrote:

> I see two immediate uses for this.  One would be to enable a "watcher" 
> process which can do useful things on the death of processes which 
> registered with it (logging, respawning, notifying other processes,
> etc).  

Do it from user space, kill(pid, 0), check for ESRCH. I might see the
benefit of a new system call if it was synchronous (wait() semantics),
but since signal delivery is asynch anyway.... 

> The second would be to enable mutual 
> suicide pacts between processes. (I'm not sure when I would use this, but 
> it sounds kind of fun.)

Same thing, kill(pid, 0).

> Anyone have any opinions on this?  

There's already a well established way to do what you want (get
non-immediate notification of process death). What benefit would your
approach give? 
-- 
Muli Ben-Yehuda
http://www.mulix.org