[boost] Re: Smart Pointers - (many) thanks and (some)questions

From: scleary_at_[hidden]
Date: 1999-12-29 09:20:16

> > > I recall a convincing presentation to the committee
> > > that you can't trust library-based threading because
> > > optimizers might reorder operations around the library
> > > calls.  That might be what Bjarne was referring to.
> > >
> >
> > But we do have language support -- 'volatile' introduces sequence points
> > (1.9p7), so I would assume that it would be possible to write such a
library
> > that the compiler could not reorder.  Interesting, though, I never
thought
> > of this before. . .
>
> It's not optimization within the library call that hurts,
> it's optimization around the library call, so it you would
> have to put volatile in your own code to protect it from
> thread switches.  I think it's sort of like the restrictions
> on setjmp, but I hurd this talk years ago and don't recall
> the deatials.
>

Are we talking about writing a threading library?  I thought we were talking
about writing a consistent interface for existing APIs (Win32, pthreads,
etc.)

        -Steve

P.S. Gaby - why isn't 'volatile' portable?  All it means is "don't optimize
this".