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

From: Yuval Ronen (ronen_yuval_at_[hidden])
Date: 2007-03-23 12:07:54

Peter Dimov wrote:
> Yuval Ronen wrote:
>> Peter Dimov wrote:
>>> Anthony Williams wrote:
>>>
>>>> However, Microsoft do not supply such an interface, so someone has
>>>> to write one. Writing one might be a good idea, but using it to
>>>> implement the C++ API, when the C++ API could be better written
>>>> using the win32 API directly seems a bad plan to me, especially if
>>>> you could use your C++ API to implement pthreads.
>>> It depends on what your plan is supposed to achieve. If you want to
>>> gradually transition from where we are now to a point where
>>> Microsoft does supply a pthread layer, it's not a bad plan at all.
>>> If you want something else, it might or might not be, depending on
>>> what exactly do you want. Anyway, I see that you are taking this as
>>> an argument, so I'll leave you to your opinion.
>> Excuse me for being a bit daft here, but why is our plan to make
>> Microsoft supply a Windows pthread layer? The reason we all want that
>> today, is because there *is no* C/C++ threading standard. Once there
>> is such a standard, we wouldn't care anymore about the underlying OS API.
>> That's the whole purpose of this (or any) standardization effort, isn't 
>> it?
> 
> That was the exact purpose of the pthreads standard. Now people on 
> POSIX-compliant OSes don't care about the underlying OS APIs (which in 
> general have little to do with pthreads) because the vendor ships a pthread 
> layer.

Maybe it was the purpose of the POSIX standard, but it was never 
accepted by the C or C++ standard committees. POSIX, for now, is an OS 
standard, not a C/C++ standard, so it *is* the OS API. Remember what the 
"OS" in "POSIX" stands for.

> Add to that the fact that all threading proposals to date agree that the 
> pthreads threading abstraction is the way to go; they all mandate its set of 
> primitives and semantics. So we do want Microsoft to offer the pthread 
> threading model to C++ programmers, even if some of us don't realize it.

Yes, we do want Microsoft to offer the pthread threading model, 
absolutely, but not necessarily the pthread syntax. They are different 
things.

> The obvious question now is: do we want Microsoft to offer this threading 
> model only to C++ programmers and not to C programmers? And what do we stand 
> to gain from that? How is it in the best interest of the C++ community to 
> demand that C code remains nonportable? 

Of course we want Microsoft to offer this threading model to C 
programmers, but it's the job of the C standard committee to define the 
exact syntax. This standard C syntax might as well be the exact POSIX 
syntax, no problem by me. But it doesn't really matter one way or the 
other, as long as the C syntax accepted is a good one. Microsoft will 
implement it because it's standard C, and people will use it because the 
syntax is good, and the model is the known-to-be-good POSIX model.