Subj : Re: STL Containers w/ Virtually Zero-Overhead Lock-Free Reads...
To   : (Usenet)
From : Maciej Sobczak
Date : Tue Sep 20 2005 09:03 pm

David Abrahams wrote:

>>>Perhaps I should create a demo virtually 
>>>zero-overhead container class...
>>
>>Please do, it would be a perfect feasibility study.
>>
>>But be careful to implement the existing interface exactly and 
>>completely, especially the guarantees about iterators lifetime and 
>>validity - this will be needed to actually apply some algorithms to it.
> 
> I could be missing something important, but it seems to me that if you
> want to "actually apply some algorithms to it" then a lock-free
> container is of little use, since you get synchronization at the wrong
> level of granularity.

That's exactly the point. STL containers do not exist in a vacuum, but 
are part of something bigger (well, STL) and their design is part of 
this bigger picture. Implementing the STL containers using some 
lock-free techniques (the goal of original poster) may force the 
implementer to drive the design somewhere else - just to show the 
advantages of lock-free programming - meaning that it will not be STL 
any longer.

Having said that, the implementation of STL that I'm using is lock-free 
in the sense that there are no locks at all. Why improve it? ;-)

But more seriously, I admit that I have no idea what the original poster 
*really* meant by lock-free STL containers, but anything that is 
constructive will be for sure of service to the community.


-- 
Maciej Sobczak : http://www.msobczak.com/
Programming    : http://www.msobczak.com/prog/

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