Re: [jamboost] Library order

From: Vladimir Prus (ghost_at_[hidden])
Date: 2004-02-02 08:08:57

Hi Jürgen,

> On Monday 02 February 2004 10:12, Vladimir Prus wrote:
> > > Shall I run some profiling ?
> >
> > If that's not too much inconvenience, then I'd appreciate seeing the
> > profile.
>
> Running bjam -d+10 ?

Yep.

>
> > > Is is possible to make library-ordering a customizable feature ?
> > > Like <hardcode-dll-paths> maybe ?
> >
> > Another approach is to rewrite the ordering code in C. Currently, we
> > run graph algorithm in jam code, and jam was never meant for that.
>
> Well, I'd like to have a mechanism to disable this completely. I fear
> that my legacy projects will suffer from an increase in startup time no
> matter how fast the algorithm will be. And this is simply due to the
> fact that library organisation went out amok some years ago. And
> unfortunately I'm not in the position to get that changed in the near
> future.

Let's first look at profile. Rewriting in C can very easily increase 
performance by an order of magnitude, and in case of library order, the 
speenup may be even greater.

> I've got severe acceptance problems from my co-workers because the
> startup-time is way too high for them. One proposal was to disable
> scanning system includes (#include <>) in order to get a much smaller
> dependency graph.

I'm not sure this will help. The performance is still high on my priority 
list, so after I finish a bunch of changes I'm working on, I'll turn to 
optimization again. Watch out for my call for profiles ;-)

> > > You only need to order libraries
> > > when doing static linking. But for this to work, we need the
> > > "order-sensitive" properties for system libraries, because these
> > > must be ordered, too.
> >
> > Well, you can declare "searched libraries" and set order between
> > them.
>
> Oh, it seems it should take a deeper look at the docs ;-)

Maybe ;-)

- Volodya