Boost logo

Boost :

From: Iain K. Hanson (iain.hanson_at_[hidden])
Date: 2003-08-28 08:48:19

On Thu, 2003-08-28 at 09:00, Geurt Vos wrote:
> >
> > > [ this is about whether <threading>single or <threading>multi ]
> > > [ should be the default jam option for building boost. Single ]
> > > [ is currently the default ]
> >
> > (**) I think I want to hear one or two other opinions before we decide
> > this decision was wrong. People seemed pretty well convinced it was
> > right once upon a time.
> >
> I think the decision was wrong. I think neither makes
> sense as default. I mean, it depends on the application
> whether single or multi threading is required. So why
> not build single _and_ multi threaded libs. Just like
> the default build results in 'debug' and 'release' libs.
I disagree. Most applications are single threaded and it takes a very
conscious choice and a lot of thought to go multi threaded. You have to
set compiler flags for MT, you have to link against special versions of
the standard C libs. You have to remember that most implementations of
the standard C++ libs are not thread safe in the sense they do not use
mutexes. You also have to remember to use re-entrant versions of
functions. These are not things that can or should be defaulted IMHO.

MT also has a cost in both space and time. One that is completely
unnecessary for single threaded programs.

It is neither a gotcha nor surprising that the default boost build is
single threaded even though boost has a threads library. My Linux box
comes with pthreads and my Windows box has threads but the default
builds on both are single threaded.

I suspect that only someone new to threads would be surprised by this
and it should probably be in the threads FAQ.

my 2p worth


Boost list run by bdawes at, gregod at, cpdaniel at, john at