Re: performance/garbage collection

From: David Abrahams (dave_at_[hidden])
Date: 2003-11-20 08:02:38

Vladimir Prus <ghost_at_[hidden]> writes:

> [moving to jamboost]
>
> Rene Rivera wrote:

>> >We maybe oughta try throwing the Boehm collector at it. But remember
>> >that it also interns all strings, so any strings that are duplicated
>> >get shared. I'm not sure how that would balance out.
>>
>> Hmm, it might be worth trying out. bjam already tries to implement a fairly
>> bad garbage collector... bad enough that the freeing collection part of it
>> is disabled ;-) So at minimum it just reuses equal strings.
>
> I thought about it previously and considered adding garbage collection to bjam 
> a non-trivial excersice. Sufficiently non-trivial so that I decided I won't 
> do it. Of course, it would be nice to have, but as far as V2 is concerned, I 
> suspect that I might rewrite all performance-critical parts in C soon ;-)
>
> Besides, according to profiler, the most time-consuming part is the hash 
> lookup. I'm not sure how faster it will become with gc.

You'd eliminate some of those. Recall that every time you form a new
string bjam does a hash lookup to intern it.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com