Re: Threading in new C++ standard
On Apr 16, 12:28 am, "Dann Corbit" <dcor...@connx.com> wrote:
Rather than create a new way of doing things:http://www.open-std.org/jtc1/=
sc22/wg21/docs/papers/2008/n2497.html
why not just pick up ACE into the existing
standard:http://www.cse.wustl.edu/~schmidt/ACE.html the same
way that the STL (and subsequently BOOST) have been subsumed?
There are serious problems with the model ACE uses.
Since it already runs on zillions of platforms, they have
obviously worked most of the kinks out of the generalized
threading and processes idea (along with many other useful
abstractions).
It's not actually used on "zillions of platforms"---as far as I
know, it supports Windows and Unix, and that's about it.
ACE is somewhat dated, and uses what was the classical model for
thread objects at the time it was developed. The general
concensus today is that this model isn't really that
appropriate, at least for a language with value semantics like
C++.
The second aspect is that ACE (and Boost, which represents a
more "state of the art" model) only address one of the reasons
threading is desired, and don't effectively support uses like
parallelizing, which are becoming important with the diffusion
of multicore machines.
Even more interesting than generalized threading would be
generalized software transactions. The Intel compiler has an
experimental version that does
this:http://softwarecommunity.intel.com/articles/eng/1460.htm
I think we're still largely at the beginning when it comes to
knowing the best idioms to support threading. Rather than
standardize something experimental, which later turns out to be
far less than ideal, I think we should only standardize an
essential minimum, on which people can build and experiment.
--
James Kanze (GABI Software) email:james.kanze@gmail.com
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