A new design and prototype implementation of boost::rw_mutex has been
uploaded to:

 http://groups.yahoo.com/group/boost/files/thread_rw_lock_v2.zip

Features/Shortcomings:

- Four types of explicit scheduling - reader_priority,
writer_priority, alternating (many reads), and alternating (single
reads). Thanks to Dan'l Miller for pointing out both types of
alternating schemes.

- Implemented completely in terms of existing Boost.Threads primitives

- Interface for a recursive_rw_mutex documented, but implementation
is not available (yet).


Comments welcome, as always.
Dave