Possible language changes

[jimmaureenrogers at att.net]

-------------- Original message from Doug Lea <dl at cs.oswego.edu>: -------------- 
> 
> Thanks for confirming that it is hopeless to aim for agreement at 
> higher layers! Some people want something Ada-like, 
> some pthreads-like. Etc. Can't win. (Exactly as discussed 
> in my talk at the VEE workshop last fall. See 
> http://gee.cs.oswego.edu/dl/cpjslides/lines.pdf or 
> http://www.research.ibm.com/vee04/talks.html). 
> 
> I think that the best that can be done at layer 3 is to define 
> some simple and basic notion of a thread: 
> create, start, destruct, get/set priorities etc, 
> block, unblock, and associate thread-locals. 
> 
> And probably some minimal integration of these with lower layers: 
> Memory effects of starting and terminating, dealing with 
> exceptions. etc. 
> 
> Can anyone make a good case for doing more ethan this? 

Of course we can. 
History tells us that low level constructs such as these will 
eventually generate a number of libraries to implement higher
level concurrency abstractions. 

Eventually C++ will need to develop a concurrency equivalent to
the STL; a standardized Threading Library. Why suffer the
incompatibilities of many libraries followed by an eventual
standardization? This would only repeat C++ history that does not
need to be repeated.

There are already several threading libraries available for C++.
Implementation of low level concurrency abstractions will simply
cause more threading libraries to be created.

Is it really necessary to define a perfect threading approach for
C++, or is it sufficient to define a very good threading approach?
I believe that a very good approach is achievable and useable within
a reasonable time frame. Perfection will never be achieved.

Jim Rogers