Re: [boost] Report from Berlin C++ Standards Committee meeting

From: Beman Dawes (bdawes_at_[hidden])
Date: 2006-04-12 18:16:49

"Ion Gaztañaga" <igaztanaga_at_[hidden]> wrote in message 
news:443ABF78.8040305_at_gmail.com...
>  >> I think all desired modifications can be proposed in the current
>>> Boost Thread rework effort and aren't too intrusive. For thread
>>> launching I prefer Kevlin Henney's proposal approach. Has the
>>> committee rejected this approach?
>>
>> You are not alone.  The problem is that Kevlin is a very busy man, and
>> has not yet produced a full working proposal.  Likewise, I am not aware
>> of a freely available reference implementation, whereas there are at
>> least 3 known separate implementations of the Boost threads interface.
>
> There is a partial implementation (threader, joiner and lockable) I
> wrote some months ago:
>
> http://boost-consulting.com/vault/index.php?&direction=0&order=&directory=Concurrent%20Programming
>
> See thread_ex.2005-08-31.zip. It's constructed above Boost.Thread. I
> didn't know then Boost.Thread's had unlock() function so I had to make
> ugly things to access Boost.Thread's mutex private functions. But the
> thread launcher is implemented with Boost.Thread and shared_ptr.
>
>> The approach has not been rejected, but is unlikely to make it in time
>> for TR2.  Likewise, the thread library itself is most likely destined
>> for TR2 rather than C++0x, although I believe the evolution group would
>> prefer us to be more aggressive on this.
>
> We can implement thread launching interface above Boost.Thread, as in
> the wrapper I wrote. Using that wrapper to launch threads and condensing
> 6 mutex types into 2 it's possible for TR2. We can let read write mutex
> (or shared_mutex, if you prefer that name) for C++0x along with a
> message queue. I will look to Pete's paper to propose changes to Boost
> mailing list (including Howard Hinnant's lock reduction).

I'd personally like you and the other Boost threading experts to keep 
working on a thread launching interface above Boost.Threads, and if it seems 
to be working out well, propose it for TR2. (That's my personal opinion - I 
have no idea what the rest of the LWG thinks.) There is still enough time 
for this if people get going. There has to be a proposal with proposed 
wording for TR2 by October, but it can have some rough edges. If the LWG 
likes it, you will have another six months to polish it and gain more use 
experience.

--Beman