Subject: Re: race in sleep.
To: None <>
From: J.T. Conklin <>
List: tech-kern
Date: 10/16/1995 17:08:42
> > I just changed libc/gen/[u]sleep.c to be less susceptible to SIGALRMs
> > coming in too late when other signal handlers are also active.
> > 
> > I also realized that the change makes another race possible:
> > a previous SIGALRM handler might now miss a signal because the sihnal mask
> > is reset earlier. I can't see a way out of this without adding one more
> > system call (to the eight which are already there as smartly pointed out
> > by th eman-page).

> Well, maybe longer term we could provide some of the system calls
> that would be needed if we did realtime signals, in this case:

Yes!  I'm in favour of this.  Realtime stuff could greatly expand the
realm of applications/installation where NetBSD would be appropriate, 
especially embedded sytems and industrial control.  ie. Why licence
VxWorks, LynxOS, etc. if NetBSD can do the job?

And as Gordon's example shows, some non-realtime userland code can be
made much simpler and less error prone.