Re: [boost] shifted_ptr<> w/ lock mechanism

From: Peter Dimov (pdimov_at_[hidden])
Date: 2003-01-29 16:13:31

From: "David Abrahams" <dave_at_[hidden]>
> "Philippe A. Bouchard" <philippeb_at_[hidden]> writes:
>
> > Lock mechanism was added to shifted_ptr<>:
> > http://groups.yahoo.com/group/boost/files/shifted_ptr.zip
> >
> > Benchmarks are also updated.  Still shifted_ptr<> is using less memory
and
> > twice faster for reconstruction time.
>
> Almost.
>
> > Notes:
> > - The first memory map report is not precise (shifted_ptr<U>).
> > - The reports were reordered (shifted_ptr<U>, shifted_ptr<T> &
> > shared_ptr<T>).
> >
> > I believe there is not that much left to do besides optimizations.
>
> Have you tried a comparison against a shared_ptr using an optimized
> count allocator?

One easy way to estimate the impact of an optimized allocator is to #define
BOOST_SP_USE_STD_ALLOCATOR, to make shared_ptr use std::allocator. On SGI
derived STLs, std::allocator is usually faster than plain new.