Thead lib from boost mutex help

Is it possable to explicity unlock and lock a mutex using the boost thread libary. There is the scoped_lock function. But that does not offer enought control over the mutex and I keep deadlocking my code.

Thanks

boost::mutex implements the "Lockable Concept" - which means it has member functions lock, try_lock, and unlock.
http://www.boost.org/doc/libs/1_37_0...mutex_concepts
http://www.boost.org/doc/libs/1_37_0...ex_types.mutex

gg