[alt.religion.computers] Ambiguity in definition of setjmp/longjmp makes them much less useful

brnstnd@kramden.acf.nyu.edu (Dan Bernstein) (10/10/90)

In article <:_A6T46@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes:
> I think it reasonable not to guarantee longjmp behaviour from within
> signals. In fact, calling longjmp from within signals is evil. The only
> thing you should do within a signal routine is set a flag... anything
> else is a bug waiting to happen.

Correct.

> Of course, you need to do this in BSD, but BSD is buggier than a dog pound.

Say what? I've written large BSD applications that don't do anything
inside signal handlers other than set flags. Where's this ``need'' you
talk about? And if you're going to insist that BSD is buggier than SysV,
how about some proof?

---Dan

brnstnd@kramden.acf.nyu.edu (Dan Bernstein) (10/10/90)

In article <G2B6:ND@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes:
> > Say what? I've written large BSD applications that don't do anything
> > inside signal handlers other than set flags. Where's this ``need'' you
> > talk about?
> To use an alarm to break a read. In system V you can do that just by setting
> a flag. In BSD you have to longjmp out.

Oh... Catch up to 4.3, where this has been fixed (in fact giving the
programmer the choice of what to do). You're right, BSD 4.2 can be quite
annoying at times.

> > And if you're going to insist that BSD is buggier than SysV,
> > how about some proof?
> I didn't say that. I said BSD is buggier than a dog pound.

Exactly. And vague statements like ``System V shows fewer signs of
feeping creaturism'' don't convince anyone that BSD is buggier than
System V.

---Dan

peter@ficc.ferranti.com (Peter da Silva) (10/10/90)

In article <18744:Oct1004:11:5190@kramden.acf.nyu.edu> brnstnd@kramden.acf.nyu.edu (Dan Bernstein) writes:
> Exactly. And vague statements like ``System V shows fewer signs of
> feeping creaturism'' don't convince anyone that BSD is buggier than
> System V.

Well, that's really great! I'm totally happy with that, and I'm glad we
could have this interchange.

I still haven't said BSD is buggier than System V. I'm saying that System
V seems better integrated and I personally trust it more. The bugs are
weirder in BSD, if you like. I wish they'd both dry up and blow away so
we could start over, but it won't happen...
-- 
Peter da Silva.   `-_-'
+1 713 274 5180.   'U`
peter@ferranti.com