From owner-freebsd-arch Fri Jan 11 13:20:19 2002 Delivered-To: freebsd-arch@freebsd.org Received: from pcnet1.pcnet.com (pcnet1.pcnet.com [204.213.232.3]) by hub.freebsd.org (Postfix) with ESMTP id 0FA3137B419 for ; Fri, 11 Jan 2002 13:20:16 -0800 (PST) Received: (from eischen@localhost) by pcnet1.pcnet.com (8.12.1/8.12.1) id g0BLJ6pb021474; Fri, 11 Jan 2002 16:19:06 -0500 (EST) Date: Fri, 11 Jan 2002 16:19:06 -0500 (EST) From: Daniel Eischen To: Terry Lambert Cc: Nate Williams , Bruce Evans , Dan Eischen , Peter Wemm , Archie Cobbs , Alfred Perlstein , arch@FreeBSD.ORG Subject: Re: Request for review: getcontext, setcontext, etc In-Reply-To: <3C3F500E.A1736EC0@mindspring.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, 11 Jan 2002, Terry Lambert wrote: > Nate Williams wrote: > > > > I'm not saying any more, since I have made negative progress attempting > > > > to explain this. > > > > > > In other words, SIGFPE is about as trappable as SIGBUS or SIGILL, > > > and means about the same thing: an unrecoverable fault. > > > > It correctly works in single threaded programs in FreeBSD 2.2, but not > > in 4.4. > > I think this is the code that was ripped out which made the 386 > happy. > > > > > If you think about it a little, since you can't guarantee delivery > > > of signals to particular threads anyway, it makes sense that SIGFPE > > > would not be useful under any circumstances in threaded programs, > > > no matter how you sliced it. I don't want to comment on how FPU exceptions can or do occur, or whether FreeBSD is broken in this regard. Just to clarify about how POSIX defines signals being delivered to threads though... SIGILL, SIGBUS, SIGFPE, etc, are synchronous signals and should be delivered to the current thread (as long as they are unmasked). I admit to being somewhat confused by what Bruce wrote also, but if we can comply with the above, that would be a good thing. -- Dan Eischen To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message