I've uploaded a new version of a barrier synchonization primitive to
 http://groups.yahoo.com/group/boost/files/thread_barrier_v2.zip

Changes/Issues:

1. HTML documentation included.
2. generational_barrier variant renamed to barrier. This will be
the primary barrier in the package.
3. barrier variant renamed to one_shot_barrier. This may be
dropped from the package as it is a limited version of #2 w/o much
compensating efficiency/functionality.
4. Both barrier variants now return a BOOST_SERIAL_THREAD value to
exactly one thread upon return from wait().
5. Behavior is still undefined if the barrier is destroyed while
some threads are still in wait(). Once Boost.Threads cancellation
mechanics are solidified, I think that barrier should cooperate
gracefully with cancellation and that this will address many of the
same needs that an exception throw from wait() would accomplish.


Comments welcome.

Thanks,
Dave