Re: [boost] Boost.Threads, N2178, N2184, et al

From: Yuval Ronen (ronen_yuval_at_[hidden])
Date: 2007-03-25 17:07:37

Peter Dimov wrote:
> Howard Hinnant wrote:
> 
>> N2184 takes the minimalist approach.  It is easier to add
>> functionality (and the associated expense) than to subtract it.  There
>> are many things the N2184::thread does not directly support.  I
>> believe this is a feature, not a bug.
> 
> This is true under the assumption that we need to target the least common 
> denominator. Try/timed joins for example come for free on Windows. So you 
> are imposing an unnecessary mutex+cv overhead for everyone wanting to use 
> try/timed joins there.
> 
> I've decided to adopt a different approach and suggest a way to equalize 
> ('harmonise' in EU terms :-) ) the platforms via the join2 extensions. In a 
> perfect world, this would lead to everyone enjoying _zero overhead_ 
> try/timed joins in a few years once pthread implementors adopt the 
> extensions.
> 
> Yes, I agree that this can be considered idealistic; but the other option is 
> to not even give them a chance to offer the functionality as there would be 
> no portable C++ way to take advantage of it. 

I'm far from being an expert on the Windows internals, but maybe what 
seems to "zero overhead" try/timed join is not really zero overhead, and 
the overhead is there, just hidden somewhere inside. If that's the case, 
then the "idealistic" way to go is to get Windows to supply a true zero 
overhead join.