Re: [boost] [thread] Question about MT API C++0X N2094

From: Howard Hinnant (hinnant_at_[hidden])
Date: 2006-11-01 16:33:33

On Nov 1, 2006, at 2:34 PM, Roland Schwarz wrote:

> Could you please provide an example where it is not possible to
> solve the problem with scoped_lock only? I simply cannot find
> one. Currently this would be the only "killer argument" for my
> proposed aggregate/POD type mutex. Therfore I am very interested
> in this.

The implementation of condition variables on Windows is an example of  
where you want to lock/unlock in a non-scoped pattern (if I'm  
understanding your question correctly).

> Are users of the library "allowed" to access them directly?
> If yes why? Isn't this redundant to locks?

Yes.  So clients can write their own mutexes and use them with  
std::locks (and vice-versa).

> E.g. the requirement for these N2094 mutex concepts would make
> implementation of my proposed POD mutex variant impossible.

I think a statically initialized mutex is very important.  I hope we  
can solve this one.  Might take a language extension...

-Howard