At 09:12 AM 1/30/2003, Peter Dimov wrote: >From: "Greg Colvin" <[EMAIL PROTECTED]> >> At 06:23 AM 1/30/2003, Peter Dimov wrote: >> > >> >To be fair, a factor of two improvement cannot just be shrugged off. But >one >> >point to keep in mind is that >> > >> >shared_ptr<X> px(new X); >> > >> >performs two allocations. We can optimize the count allocation until >we're >> >blue in the face but in a real project the whole expression will probably >> >remain a bottleneck; so it's likely that X will acquire a class-specific >> >operator new. And a X with a class-specific new can no longer be used >with >> >shifted_ptr. >> >> I read a paper yesterday from the latest OOPSLA proceedings >> that argued that a class-specific new is almost never a win >> compared to a high-quality general purpose allocator like >> LEA. > >This is the argument I've been using every time the question of adding an optimized >count allocator to shared_ptr came up.
The counter-argument is that the allocators supplied by many vendors are nowhere near as good as LEA. So it might be a good idea to optionally use boost::pool in shared_ptr. And it would be a good Boost project to provide a high-quality replacement operator new. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
