Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 22 Nov 1999 19:57:56 -0800 (PST)
From:      Julian Elischer <julian@whistle.com>
To:        Chuck Robey <chuckr@picnic.mat.net>
Cc:        Nate Williams <nate@mt.sri.com>, "Daniel M. Eischen" <eischen@vigrid.com>, freebsd-arch@freebsd.org
Subject:   Re: Threads
Message-ID:  <Pine.BSF.4.10.9911221953140.9392-100000@current1.whistle.com>
In-Reply-To: <Pine.BSF.4.10.9911221929070.20163-100000@picnic.mat.net>

next in thread | previous in thread | raw e-mail | index | archive | help


On Mon, 22 Nov 1999, Chuck Robey wrote:

> On Sat, 20 Nov 1999, Julian Elischer wrote:
> 
> > 
> > 
> > On Sat, 20 Nov 1999, Nate Williams wrote:
> > 
> > > > New calls must be able to return and say 
> > > > "hey it's not me returnuing, but actually a new KSE, "
> > > 
> > > Not only that, but you need a way for it to be 'aborted' out and have it
> > > cleanup as it goes.  I suspect that this will require re-writing a large
> > > number of syscalls with threading in mind, and leaving the 'old' calls
> > > in place will allow more flexibility as things change.
> > > 
> > > I could envision the 'old' calls going away at some point as the new
> > > calls get completely fleshed out and tested, to be replaced with simple
> > > wrappers for the threaded calls.
> > > 
> > 
> > Maybe in the libraries, but we will need to keep the old syscalls in the
> > kernel effectively forever. (for old binaries) It's not much of a cost..
> > (look at linux emulation).
> 
> If I can ask one question, how will we cover things like errno, which
> we'll want to be in thread-specific storage, but not on the stack (I
> think)?
> 
I think the usual errno hack is just fine..
we've already cleaned out other occurances of errno from a lot of code.

#define errno (*threadspecific->errnum)
or
#define errno (errnum[thread_ID])

Actually there is no reason errno can't be on your local stack, in th
einitial frame, as long as you have a way to reference it.

> 
> ----------------------------------------------------------------------------
> Chuck Robey                | Interests include C programming, Electronics,
> 213 Lakeside Dr. Apt. T-1  | communications, and signal processing.
> Greenbelt, MD 20770        | I run picnic.mat.net: FreeBSD-current(i386) and
> (301) 220-2114             |       jaunt.mat.net : FreeBSD-current(Alpha)
> ----------------------------------------------------------------------------
> 
> 





To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-arch" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.10.9911221953140.9392-100000>