CGAL users discussion list

[Marc Glisse <>]

On Tue, 1 May 2012, Philipp Moeller wrote:

> Another approach I have been pondering is to simply throw all our ref
> counted objects into shared_ptr.

That is a possibility, but the interface is far from a perfect match, 
especially if you take all the variants we have in cgal into account.

> At least the boost version uses atomic counters on most platforms

The standard libraries that come with gcc, llvm and visual studio all do.

> This might have some drawbacks I don't see yet. At least
> boost::shared_ptr is known to have some performance deficiencies
> compared to vendor implementations.

shared_ptr has heavier functionalities than a simple reference-counted 
structure which makes it unavoidably slower. The boost library might be 
particularly bad, I don't know, but the last time I looked (possibly 
2009), if I remember correctly, it was orders of magnitude slower than 
anything else I tried, for this use. Or maybe that was gcc's placeholder 
atomic implementation (they have a real one now)? Well, boost certainly 
wasn't among the faster alternatives.

It is certainly worth reevaluating today, if someone has time...

--
Marc Glisse